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Gafane-Matemane LF, Craig A, Kruger R, Alaofin OS, Ware LJ, Jones ESW, Kengne AP. Hypertension in sub-Saharan Africa: the current profile, recent advances, gaps, and priorities. J Hum Hypertens 2025; 39:95-110. [PMID: 38698111 PMCID: PMC11867975 DOI: 10.1038/s41371-024-00913-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 04/15/2024] [Accepted: 04/17/2024] [Indexed: 05/05/2024]
Abstract
Recent global and regional reports consistently confirm the high and increasing prevalence of hypertension in sub-Saharan Africa (SSA), with poor detection, treatment, and control rates. This narrative review summarises the burden of hypertension in SSA and recent findings from community-based hypertension management strategies. We further outline prominent risk factors according to recent data and associated underlying mechanisms for hypertension development. An extensive review of literature showed that most countries have reported on the prevalence of hypertension during 2017-2023, despite limitations linked to the lack of nationally representative studies, heterogeneity of sampling and data collection methods. Task-shifting approaches that assign roles to model patients and community health workers reported improved linkage to healthcare services and adherence to medication, with inconsistent findings on blood pressure (BP)-lowering effects over time. The regularly reported risk factors include unhealthy diet, sedentary lifestyle, increased adiposity and underweight, ageing, level of education, and/or income as well as psychosocial factors. Newer data on the pathophysiological mechanisms leading to hypertension and potential areas of intervention are reported from children and adults and include, among others, salt-handling and volume overload, endothelial function, BP dipping patterns and the role of human immunodeficiency virus . To conclude, significant strides have been made in data reporting from SSA on the burden of hypertension in the region as well as biomarker research to improve understanding and identification of areas of intervention. However, gaps remain on linkage between knowledge generation, translation, and implementation research. Coordinated studies addressing both discovery science and public health are crucial to curb hypertension development and improve management in SSA.
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Affiliation(s)
- Lebo F Gafane-Matemane
- Hypertension in Africa Research Team, North-West University, Potchefstroom, 2520, South Africa.
- SAMRC Research Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, 2520, South Africa.
| | - Ashleigh Craig
- SAMRC/Wits Developmental Pathways for Health Research Unit (DPHRU), University of the Witwatersrand, Soweto, 1864, South Africa
| | - Ruan Kruger
- Hypertension in Africa Research Team, North-West University, Potchefstroom, 2520, South Africa
- SAMRC Research Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, 2520, South Africa
| | - Omotayo S Alaofin
- Hypertension in Africa Research Team, North-West University, Potchefstroom, 2520, South Africa
| | - Lisa J Ware
- SAMRC/Wits Developmental Pathways for Health Research Unit (DPHRU), University of the Witwatersrand, Soweto, 1864, South Africa
| | - Erika S W Jones
- Division of Nephrology and Hypertension, Groote Schuur Hospital and Kidney and Hypertension Research Unit, University of Cape Town, Cape Town, South Africa
| | - Andre Pascal Kengne
- Non-Communicable Diseases Research Unit, South African Medical Research Council, Francie Van Zijl Dr, Parow Valley, Cape Town, 7501, South Africa
- Department of Biological and Environmental Sciences, Faculty of Natural Sciences, Walter Sisulu University, Mthatha, South Africa
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Young BE, Kissell CE, Vranish JR, Stephens BY, Holwerda SW, Fadel PJ. Sex differences in sympathetic transduction in black and white adults: implications for racial disparities in hypertension and cardiovascular disease risk. Am J Physiol Heart Circ Physiol 2024; 327:H672-H680. [PMID: 39058432 DOI: 10.1152/ajpheart.00337.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 07/16/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024]
Abstract
The prevalence of hypertension in non-Hispanic black (BL) individuals is the greatest of any racial/ethnic group. Whereas women generally display lower rates of hypertension than men of the same background, BL women display a similar if not greater burden of hypertension compared with BL men. The risk for cardiovascular disease and related events is also highest in BL individuals. Given the importance of the sympathetic nervous system for the regulation of the cardiovascular system, a growing body of literature has investigated sympathetic function in BL and non-Hispanic white (WH) individuals. Here, we are focused on emerging evidence indicating that sympathetic function may be altered in BL individuals, with particular emphasis on the process by which bursts of muscle sympathetic nerve activity (MSNA) are transduced into vasoconstriction and increases in blood pressure (sympathetic vascular transduction). To synthesize this growing body of literature we discuss sex and race differences in 1) sympathetic outflow, 2) sympathetic vascular transduction, and 3) adrenergic receptor sensitivity. Sex differences are discussed foremost, to set the stage for new data indicating a sex dimorphism in sympathetic regulation in BL individuals. Specifically, we highlight evidence for a potential neurogenic phenotype including greater adiposity-independent sympathetic outflow and enhanced sympathetic vascular transduction in BL men that is not observed in BL women. The implications of these findings for the greater hypertension and cardiovascular disease risk in BL adults are discussed along with areas that require further investigation.
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Affiliation(s)
- Benjamin E Young
- Department of Kinesiology, Health Promotion and Recreation, College of Education, University of North Texas, Denton, Texas, United States
| | - Claire E Kissell
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas, United States
| | - Jennifer R Vranish
- Department of Integrative Physiology and Health Science, Alma College, Alma, Michigan, United States
| | - Brandi Y Stephens
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas, United States
| | - Seth W Holwerda
- Department of Anesthesiology, Pain and Perioperative Medicine, Kansas University Medical Center, Kansas City, Kansas, United States
| | - Paul J Fadel
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas, United States
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Rahman S, Gamboa A, Saleem M, Kulapatana S, Diedrich A, Biaggioni I, Kirabo A, Shibao CA. Complete autonomic blockade reveals nitric oxide contribution to blood pressure regulation in obese Black women. Clin Auton Res 2024; 34:427-436. [PMID: 39090323 PMCID: PMC11362192 DOI: 10.1007/s10286-024-01050-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 06/26/2024] [Indexed: 08/04/2024]
Abstract
PURPOSE Hypertension is one of the major causes of cardiovascular morbidity and mortality in the USA and disproportionately affects Black women. Endothelial-derived nitric oxide (eNO) substantially regulates blood pressure in humans, and impaired NO-mediated vasodilation has been reported in the Black population. Previous studies using an NO synthase inhibitor, NG-monomethyl-L-arginine (L-NMMA) did not fully determine the NO contribution to blood pressure because of baroreflex buffering. Therefore, in the present study we used trimethaphan, a ganglionic blocker, to inhibit baroreflex buffering and study NO modulation of blood pressure in Black women during L-NMMA infusion. METHODS L-NMMA at doses of 250 μg/kg per minute was infused in combination with trimethaphan at doses of 4 mg/min to eliminate baroreflex mechanisms. Heart rate (HR) was obtained with continuous electrocardiogram monitoring, and continuous blood pressure was measured with the volume clamp method. The increase in systolic blood pressure (SBP) during both infusions was used to estimate the contribution of NO to blood pressure. RESULTS Ten Black (age range 30-50 years, body mass index [BMI] 30-45 kg/m2), and nine White women (age range 30-50 years, body mass index 30-45 kg/m2) were enrolled in this study. During autonomic blockade, there was no difference in the decrease in SBP between Black and White women (- 20 ± 16.45 vs. - 24 ± 15.49 mm Hg, respectively; P = 0.659). When autonomic blockade was combined with L-NMMA, Black women had a significant increase in SBP compared to White women (54 ± 13.62 vs. 39 ± 09.64 mm Hg, respectively; P = 0.022, respectively). CONCLUSION Autonomic blood pressure regulation was similar between Black and White women. However, NO contribution to blood pressure was significantly greater in Black women compared to White women. REGISTRATION ClinicalTrials.gov: NCT01122407.
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Affiliation(s)
- Sharla Rahman
- Department of Medicine, Epidemiology, Vanderbilt University School of Medicine, Nashville, TN, 37212-8802, USA
| | - Alfredo Gamboa
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Room 536 Robinson Research Building, Nashville, TN, 37212-8802, USA
| | - Mohammad Saleem
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Room 536 Robinson Research Building, Nashville, TN, 37212-8802, USA
| | - Surat Kulapatana
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Room 536 Robinson Research Building, Nashville, TN, 37212-8802, USA
- Department of Physiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand
| | - André Diedrich
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Room 536 Robinson Research Building, Nashville, TN, 37212-8802, USA
| | - Italo Biaggioni
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Room 536 Robinson Research Building, Nashville, TN, 37212-8802, USA
| | - Annet Kirabo
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, P415C Medical Research Building IV, 2215 Garland Avenue, Nashville, TN, 37232, USA.
| | - Cyndya A Shibao
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Room 536 Robinson Research Building, Nashville, TN, 37212-8802, USA.
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Turner CG, Hayat MJ, Otis JS, Quyyumi AA, Wong BJ. The effect of endothelin a receptor inhibition and biological sex on cutaneous microvascular function in non-Hispanic Black and White young adults. Physiol Rep 2024; 12:e16149. [PMID: 39016164 PMCID: PMC11252828 DOI: 10.14814/phy2.16149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 06/28/2024] [Accepted: 07/04/2024] [Indexed: 07/18/2024] Open
Abstract
The purpose of this study was to investigate whether endothelin-A receptor (ETAR) inhibition in non-Hispanic Black (NHB) and White (NHW) young adults depends on biological sex. We recruited females during low hormone (n = 22) and high hormone (n = 22) phases, and males (n = 22). Participants self-identified as NHB (n = 33) or NHW (n = 33). Participants were instrumented with two microdialysis fibers: (1) lactated Ringer's (control) and (2) 500 nM BQ-123 (ETAR antagonist). Local heating was used to elicit cutaneous vasodilation, and an infusion of 20 mM L-NAME to quantify NO-dependent vasodilation. At control sites, NO-dependent vasodilation was lowest in NHB males (46 ± 13 %NO) and NHB females during low hormone phases (47 ± 12 %NO) compared to all NHW groups. Inhibition of ETAR increased NO-dependent vasodilation in NHB males (66 ± 13 %NO), in both groups of females during low hormone phases (NHW, control: 64 ± 12 %NO, BQ-123: 85 ± 11 %NO; NHB, BQ-123: 68 ± 13 %NO), and in NHB females during high hormone phases (control: 61 ± 11 %NO, BQ-123: 83 ± 9 %NO). There was no effect for ETAR inhibition in NHW males or females during high hormone phases. These data suggest the effect of ETAR inhibition on NO-dependent vasodilation is influenced by biological sex and racial identity.
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Affiliation(s)
- Casey G. Turner
- Department of Kinesiology and HealthGeorgia State UniversityAtlantaGeorgiaUSA
- Molecular Cardiology Research InstituteTufts Medical CenterBostonMassachusettsUSA
| | - Matthew J. Hayat
- School of Public HealthGeorgia State UniversityAtlantaGeorgiaUSA
| | - Jeffrey S. Otis
- Department of Kinesiology and HealthGeorgia State UniversityAtlantaGeorgiaUSA
| | - Arshed A. Quyyumi
- Emory Clinical Cardiovascular Research InstituteEmory University School of MedicineAtlantaGeorgiaUSA
| | - Brett J. Wong
- Department of Kinesiology and HealthGeorgia State UniversityAtlantaGeorgiaUSA
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Reindl M, Lechner I, Reinstadler SJ, Metzler B. Cardiac remodelling patterns in hypertension: does ethnicity matter? Eur Heart J Cardiovasc Imaging 2024; 25:912-913. [PMID: 38700002 DOI: 10.1093/ehjci/jeae116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Accepted: 04/23/2024] [Indexed: 05/05/2024] Open
Affiliation(s)
- Martin Reindl
- University Clinic of Internal Medicine III, Cardiology and Angiology, Medical University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria
| | - Ivan Lechner
- University Clinic of Internal Medicine III, Cardiology and Angiology, Medical University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria
| | - Sebastian J Reinstadler
- University Clinic of Internal Medicine III, Cardiology and Angiology, Medical University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria
| | - Bernhard Metzler
- University Clinic of Internal Medicine III, Cardiology and Angiology, Medical University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria
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Stephens BY, Young BE, Nandadeva D, Skow RJ, Greaney JL, Brothers RM, Fadel PJ. Sympathetic transduction at rest and during cold pressor test in young healthy non-Hispanic Black and White women. Am J Physiol Regul Integr Comp Physiol 2023; 325:R682-R691. [PMID: 37781734 PMCID: PMC11178294 DOI: 10.1152/ajpregu.00073.2023] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 09/01/2023] [Accepted: 09/20/2023] [Indexed: 10/03/2023]
Abstract
Non-Hispanic Black (BL) individuals have the highest prevalence of hypertension and cardiovascular disease (CVD) compared with all other racial/ethnic groups. Previous work focused on racial disparities in sympathetic control and blood pressure (BP) regulation between young BL and White (WH) adults, have mainly included men. Herein, we hypothesized that BL women would exhibit augmented resting sympathetic vascular transduction and greater sympathetic and BP reactivity to cold pressor test (CPT) compared with WH women. Twenty-eight young healthy women (BL: n = 14, 22 [Formula: see text] 4 yr; WH: n = 14, 22 [Formula: see text] 4 yr) participated. Beat-to-beat BP (Finometer), common femoral artery blood flow (duplex Doppler ultrasound), and muscle sympathetic nerve activity (MSNA; microneurography) were continuously recorded. In a subset (BL n = 10, WH n = 11), MSNA and BP were recorded at rest and during a 2-min CPT. Resting sympathetic vascular transduction was quantified as changes in leg vascular conductance (LVC) and mean arterial pressure (MAP) following spontaneous bursts of MSNA using signal averaging. Sympathetic and BP reactivity were quantified as changes in MSNA and MAP during the last minute of CPT. There were no differences in nadir LVC following resting MSNA bursts between BL (-8.70 ± 3.43%) and WH women (-7.30 ± 3.74%; P = 0.394). Likewise, peak increases in MAP following MSNA bursts were not different between groups (BL: +2.80 ± 1.42 mmHg; vs. WH: +2.99 ± 1.15 mmHg; P = 0.683). During CPT, increases in MSNA and MAP were also not different between BL and WH women, with similar transduction estimates between groups (ΔMAP/ΔMSNA; P = 0.182). These findings indicate that young, healthy BL women do not exhibit exaggerated sympathetic transduction or augmented sympathetic and BP reactivity during CPT.NEW & NOTEWORTHY This study was the first to comprehensively investigate sympathetic vascular transduction and sympathetic and BP reactivity during a cold pressor test in young, healthy BL women. We demonstrated that young BL women do not exhibit exaggerated resting sympathetic vascular transduction and do not have augmented sympathetic or BP reactivity during cold stress compared with their WH counterparts. Collectively, these findings suggest that alterations in sympathetic transduction and reactivity are not apparent in young, healthy BL women.
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Affiliation(s)
- Brandi Y Stephens
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, United States
| | - Benjamin E Young
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, United States
- Department of Applied Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Damsara Nandadeva
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, United States
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
| | - Rachel J Skow
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, United States
| | - Jody L Greaney
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, United States
| | - R Matthew Brothers
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, United States
| | - Paul J Fadel
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, United States
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Stavres J, Faulkner B, Haynes H, Newsome TA, Dearmon M, Ladner KR, Luck JC. Additive influence of exercise pressor reflex activation on Valsalva responses in white and black adults. Eur J Appl Physiol 2023; 123:2259-2270. [PMID: 37269380 DOI: 10.1007/s00421-023-05240-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 05/20/2023] [Indexed: 06/05/2023]
Abstract
AIM This study aimed to determine if activation of the exercise pressor reflex exerts additive or redundant influences on the autonomic responses to the Valsalva maneuver (VL), and if these responses differ between White and Black or African American (B/AA) individuals. METHODS Twenty participants (B/AA n = 10, White n = 10) performed three separate experimental trials. In the first trial, participants performed two VLs in a resting condition. In a second trial, participants performed 5 min of continuous handgrip (HG) exercise at 35% of the predetermined maximal voluntary contraction. In a third and final trial, participants repeated the 5-min bout of HG while also performing two VLs during the 4th and 5th minutes. Beat by beat blood pressure and heart rate (HR) were recorded continuously and the absolute systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), and heart rate (HR) responses were reported for phases I-IV of each VL. RESULTS No significant group by trial interactions or main effects of group were observed for any phase of the VL (all p ≥ 0.36). However, significant main effects of time were observed for blood pressure and heart rate during phases IIa-IV (all p ≤ 0.02). Specifically, the addition of HG exercise exaggerated the hypertensive responses during phases IIb and IV (all p ≤ 0.04) and blunted the hypotensive responses during phases IIa and III (all p ≤ 0.01). CONCLUSIONS These results suggest that activation of the exercise pressor reflex exerts an additive influence on autonomic responses to the VL maneuver in both White and B/AA adults.
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Affiliation(s)
- Jon Stavres
- School of Kinesiology and Nutrition, University of Southern Mississippi, Hattiesburg, MS, USA.
| | - Barry Faulkner
- School of Kinesiology and Nutrition, University of Southern Mississippi, Hattiesburg, MS, USA
| | - Hunter Haynes
- School of Kinesiology and Nutrition, University of Southern Mississippi, Hattiesburg, MS, USA
| | - Ta'Quoris A Newsome
- School of Kinesiology and Nutrition, University of Southern Mississippi, Hattiesburg, MS, USA
| | - Marshall Dearmon
- School of Kinesiology and Nutrition, University of Southern Mississippi, Hattiesburg, MS, USA
| | - Kenneth R Ladner
- School of Kinesiology and Nutrition, University of Southern Mississippi, Hattiesburg, MS, USA
| | - J Carter Luck
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, PA, USA
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Turner CG, Hayat MJ, Grosch C, Quyyumi AA, Otis JS, Wong BJ. Endothelin A receptor inhibition increases nitric oxide-dependent vasodilation independent of superoxide in non-Hispanic Black young adults. J Appl Physiol (1985) 2023; 134:891-899. [PMID: 36892887 PMCID: PMC10042601 DOI: 10.1152/japplphysiol.00739.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023] Open
Abstract
Young non-Hispanic Black adults have reduced microvascular endothelial function compared with non-Hispanic White counterparts, but the mechanisms are not fully elucidated. The purpose of this study was to investigate the effect of endothelin-1 A receptor (ETAR) and superoxide on cutaneous microvascular function in young non-Hispanic Black (n = 10) and White (n = 10) adults. Participants were instrumented with four intradermal microdialysis fibers: 1) lactated Ringer's (control), 2) 500 nM BQ-123 (ETAR antagonist), 3) 10 μM tempol (superoxide dismutase mimetic), and 4) BQ-123 + tempol. Skin blood flow was assessed via laser-Doppler flowmetry (LDF), and each site underwent rapid local heating from 33°C to 39°C. At the plateau of local heating, 20 mM l-NAME [nitric oxide (NO) synthase inhibitor] was infused to quantify NO-dependent vasodilation. Data are means ± standard deviation. NO-dependent vasodilation was decreased in non-Hispanic Black compared with non-Hispanic White young adults (P < 0.01). NO-dependent vasodilation was increased at BQ-123 sites (73 ± 10% NO) and at BQ-123 + tempol sites (71 ± 10%NO) in non-Hispanic Black young adults compared with control (53 ± 13%NO, P = 0.01). Tempol alone had no effect on NO-dependent vasodilation in non-Hispanic Black young adults (63 ± 14%NO, P = 0.18). NO-dependent vasodilation at BQ-123 sites was not statistically different between non-Hispanic Black and White (80 ± 7%NO) young adults (P = 0.15). ETAR contributes to reduced NO-dependent vasodilation in non-Hispanic Black young adults independent of superoxide, suggesting a greater effect on NO synthesis rather than NO scavenging via superoxide.NEW & NOTEWORTHY Endothelin-1 A receptors (ETARs) have been shown to reduce endothelial function independently and through increased production of superoxide. We show that independent ETAR inhibition increases microvascular endothelial function in non-Hispanic Black young adults. However, administration of a superoxide dismutase mimetic alone and in combination with ETAR inhibition had no effect on microvascular endothelial function suggesting that, in the cutaneous microvasculature, the negative effects of ETAR in non-Hispanic Black young adults are independent of superoxide production.
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Affiliation(s)
- Casey G Turner
- Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia, United States
| | - Matthew J Hayat
- Department of Population Health Sciences, School of Public Health, Georgia State University, Atlanta, Georgia, United States
| | - Caroline Grosch
- Department of Population Health Sciences, School of Public Health, Georgia State University, Atlanta, Georgia, United States
| | - Arshed A Quyyumi
- Emory Clinical Cardiovascular Research Institute, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Jeffrey S Otis
- Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia, United States
| | - Brett J Wong
- Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia, United States
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Morgan RW, Berg RA, Reeder RW, Carpenter TC, Franzon D, Frazier AH, Graham K, Meert KL, Nadkarni VM, Naim MY, Tilford B, Wolfe HA, Yates AR, Sutton RM. The physiologic response to epinephrine and pediatric cardiopulmonary resuscitation outcomes. Crit Care 2023; 27:105. [PMID: 36915182 PMCID: PMC10012560 DOI: 10.1186/s13054-023-04399-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 03/08/2023] [Indexed: 03/16/2023] Open
Abstract
BACKGROUND Epinephrine is provided during cardiopulmonary resuscitation (CPR) to increase systemic vascular resistance and generate higher diastolic blood pressure (DBP) to improve coronary perfusion and attain return of spontaneous circulation (ROSC). The DBP response to epinephrine during pediatric CPR and its association with outcomes have not been well described. Thus, the objective of this study was to measure the association between change in DBP after epinephrine administration during CPR and ROSC. METHODS This was a prospective multicenter study of children receiving ≥ 1 min of CPR with ≥ 1 dose of epinephrine and evaluable invasive arterial BP data in the 18 ICUs of the ICU-RESUS trial (NCT02837497). Blood pressure waveforms underwent compression-by-compression quantitative analysis. The mean DBP before first epinephrine dose was compared to mean DBP two minutes post-epinephrine. Patients with ≥ 5 mmHg increase in DBP were characterized as "responders." RESULTS Among 147 patients meeting inclusion criteria, 66 (45%) were characterized as responders and 81 (55%) were non-responders. The mean increase in DBP with epinephrine was 4.4 [- 1.9, 11.5] mmHg (responders: 13.6 [7.5, 29.3] mmHg versus non-responders: - 1.5 [- 5.0, 1.5] mmHg; p < 0.001). After controlling for a priori selected covariates, epinephrine response was associated with ROSC (aRR 1.60 [1.21, 2.12]; p = 0.001). Sensitivity analyses identified similar associations between DBP response thresholds of ≥ 10, 15, and 20 mmHg and ROSC; DBP responses of ≥ 10 and ≥ 15 mmHg were associated with higher aRR of survival to hospital discharge and survival with favorable neurologic outcome (Pediatric Cerebral Performance Category score of 1-3 or no worsening from baseline). CONCLUSIONS The change in DBP following epinephrine administration during pediatric in-hospital CPR was associated with return of spontaneous circulation.
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Affiliation(s)
- Ryan W Morgan
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania, 3401 Civic Center Boulevard, Wood Building - 6104, Philadelphia, PA, 19104, USA.
| | - Robert A Berg
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania, 3401 Civic Center Boulevard, Wood Building - 6104, Philadelphia, PA, 19104, USA
| | - Ron W Reeder
- Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Todd C Carpenter
- Department of Pediatrics, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO, USA
| | - Deborah Franzon
- Department of Pediatrics, Benioff Children's Hospital, University of California, San Francisco, San Francisco, CA, USA
| | - Aisha H Frazier
- Nemours Cardiac Center, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA.,Department of Pediatrics, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Kathryn Graham
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania, 3401 Civic Center Boulevard, Wood Building - 6104, Philadelphia, PA, 19104, USA
| | - Kathleen L Meert
- Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit, MI, USA
| | - Vinay M Nadkarni
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania, 3401 Civic Center Boulevard, Wood Building - 6104, Philadelphia, PA, 19104, USA
| | - Maryam Y Naim
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania, 3401 Civic Center Boulevard, Wood Building - 6104, Philadelphia, PA, 19104, USA
| | - Bradley Tilford
- Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit, MI, USA
| | - Heather A Wolfe
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania, 3401 Civic Center Boulevard, Wood Building - 6104, Philadelphia, PA, 19104, USA
| | - Andrew R Yates
- Department of Pediatrics, Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| | - Robert M Sutton
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania, 3401 Civic Center Boulevard, Wood Building - 6104, Philadelphia, PA, 19104, USA
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Monfredi OJ, Moore CC, Sullivan BA, Keim-Malpass J, Fairchild KD, Loftus TJ, Bihorac A, Krahn KN, Dubrawski A, Lake DE, Moorman JR, Clermont G. Continuous ECG monitoring should be the heart of bedside AI-based predictive analytics monitoring for early detection of clinical deterioration. J Electrocardiol 2023; 76:35-38. [PMID: 36434848 PMCID: PMC10061545 DOI: 10.1016/j.jelectrocard.2022.10.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/01/2022] [Accepted: 10/22/2022] [Indexed: 11/24/2022]
Abstract
The idea that we can detect subacute potentially catastrophic illness earlier by using statistical models trained on clinical data is now well-established. We review evidence that supports the role of continuous cardiorespiratory monitoring in these predictive analytics monitoring tools. In particular, we review how continuous ECG monitoring reflects the patient and not the clinician, is less likely to be biased, is unaffected by changes in practice patterns, captures signatures of illnesses that are interpretable by clinicians, and is an underappreciated and underutilized source of detailed information for new mathematical methods to reveal.
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Affiliation(s)
- Oliver J Monfredi
- Center for Advanced Medical Analytics, University of Virginia, United States of America; Department of Medicine, University of Virginia, United States of America
| | - Christopher C Moore
- Center for Advanced Medical Analytics, University of Virginia, United States of America; Department of Medicine, University of Virginia, United States of America
| | - Brynne A Sullivan
- Center for Advanced Medical Analytics, University of Virginia, United States of America; Department of Pediatrics, University of Virginia, United States of America
| | - Jessica Keim-Malpass
- Center for Advanced Medical Analytics, University of Virginia, United States of America; School of Nursing, University of Virginia, United States of America
| | - Karen D Fairchild
- Center for Advanced Medical Analytics, University of Virginia, United States of America; Department of Pediatrics, University of Virginia, United States of America
| | - Tyler J Loftus
- Department of Surgery, University of Florida, United States of America
| | - Azra Bihorac
- Department of Medicine, University of Florida, United States of America
| | - Katherine N Krahn
- Center for Advanced Medical Analytics, University of Virginia, United States of America; Department of Medicine, University of Virginia, United States of America
| | - Artur Dubrawski
- Robotics Institute, Carnegie Mellon University, United States of America
| | - Douglas E Lake
- Center for Advanced Medical Analytics, University of Virginia, United States of America; Department of Medicine, University of Virginia, United States of America
| | - J Randall Moorman
- Center for Advanced Medical Analytics, University of Virginia, United States of America; Department of Medicine, University of Virginia, United States of America.
| | - Gilles Clermont
- Department of Critical Care, University of Pittsburgh, United States of America
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11
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Akins JD, Martin ZT, Patik JC, Curtis BM, Campbell JC, Olvera G, Brothers RM. Young, non-hispanic black men and women exhibit divergent peripheral and cerebral vascular reactivity. Exp Physiol 2022; 107:450-461. [PMID: 35344241 PMCID: PMC9058228 DOI: 10.1113/ep090168] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 03/21/2022] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of the study? Does peripheral and cerebral vascular function differ in young, non-Hispanic Black men and women? What is the main finding and its importance? The non-Hispanic, Black women in this study presented greater peripheral conduit artery and cerebrovascular reactivity, yet similar peripheral microvascular function relative to the non-Hispanic, Black men. These preliminary findings suggest that young, Black women and men possess divergent vascular function, possibly contributing to the unique non-Hispanic Black sex differences in cardiovascular and cerebrovascular diseases. ABSTRACT In the U.S., cardiovascular and cerebrovascular diseases remain more prominent in the non-Hispanic Black (BL) population relative to other racial/ethnic groups. Typically, sex differences emerge in the manifestation of these diseases, though these differences may not fully materialize in the BL population. While numerous mechanisms are implicated, differences in vascular function likely contribute. Research has demonstrated blunted vasodilation in several vascular regions in BL versus non-Hispanic White individuals, though much of this work did not assess sex differences. Therefore, this study aimed to ascertain if indices of vascular function are different between young, BL women (BW) and men (BM). Eleven BW and 15 BM (22 (4) vs. 23 (3) y) participated in this study. Each participant underwent testing for brachial artery flow-mediated dilation (FMD), post-occlusive reactive hyperemia (RH), and cerebral vasomotor reactivity during rebreathing-induced hypercapnia. BW exhibited greater adjusted FMD than BM (P < 0.05 for all), but similar or lower RH when assessed as blood velocity (P > 0.39 for all) or blood flow reactivity (P < 0.05 for all), respectively. Across a range of hypercapnia, BW had greater middle cerebral artery blood velocity and cerebrovascular conductance index than BM (P < 0.001 for both). These preliminary data suggest that young, BW have greater vascular function relative to young, BM, though this was inconsistent across different indices. These findings provide insight into the divergent epidemiological findings between BM and BW. Further research is needed to elucidate possible mechanisms and relate these physiological responses to epidemiological observations. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- John D Akins
- Department of Kinesiology, The University of Texas at Arlington, Arlington, TX, USA
| | - Zachary T Martin
- Department of Kinesiology, The University of Texas at Arlington, Arlington, TX, USA
| | - Jordan C Patik
- Department of Kinesiology, The University of Texas at Arlington, Arlington, TX, USA.,Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA
| | - Bryon M Curtis
- Department of Kinesiology, The University of Texas at Arlington, Arlington, TX, USA.,Institute for Exercise and Environmental Medicine, Dallas, TX, USA
| | - Jeremiah C Campbell
- Department of Kinesiology, The University of Texas at Arlington, Arlington, TX, USA
| | - Guillermo Olvera
- Department of Kinesiology, The University of Texas at Arlington, Arlington, TX, USA.,Institute for Exercise and Environmental Medicine, Dallas, TX, USA
| | - R Matthew Brothers
- Department of Kinesiology, The University of Texas at Arlington, Arlington, TX, USA
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12
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Bunsawat K, Grosicki GJ, Jeong S, Robinson AT. Racial and ethnic disparities in cardiometabolic disease and COVID-19 outcomes in White, Black/African American, and Latinx populations: Physiological underpinnings. Prog Cardiovasc Dis 2022; 71:11-19. [PMID: 35490869 PMCID: PMC9050188 DOI: 10.1016/j.pcad.2022.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 04/24/2022] [Indexed: 02/05/2023]
Abstract
Coronavirus disease 2019 (COVID-19) is a highly contagious respiratory illness caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that began spreading globally in late 2019. While most cases of COVID-19 present with mild to moderate symptoms, COVID-19 was the third leading cause of mortality in the United States in 2020 and 2021. Though COVID-19 affects individuals of all races and ethnicities, non-Hispanic Black and Hispanic/Latinx populations are facing an inequitable burden of COVID-19 characterized by an increased risk for hospitalization and mortality. Importantly, non-Hispanic Black and Hispanic/Latinx adults have also faced a greater risk of non-COVID-19-related mortality (e.g., from cardiovascular disease/CVD) during the pandemic. Contributors to the racial disparities in morbidity and mortality during the pandemic are multi-factorial as we discuss in our companion article on social determinants of health. However, profound racial variation in the prevalence of CVD and metabolic diseases may serve as a key driver of worse COVID-19-related and non-COVID-19-related health outcomes among racial and ethnic minority groups. Within this review, we provide data emphasizing the inequitable burden of CVD and metabolic diseases among non-Hispanic Black and Hispanic/Latinx populations. We also discuss the pathophysiology of these conditions, with a focus on how aberrant physiological alterations in the context of CVD and metabolic diseases manifest to increase susceptibility to severe COVID-19.
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Affiliation(s)
- Kanokwan Bunsawat
- Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT 84132, USA; Geriatric Research, Education, and Clinical Center, George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, UT 84148, USA
| | - Gregory J Grosicki
- Department of Health Sciences and Kinesiology, Biodynamics and Human Performance Center, Georgia Southern University (Armstrong Campus), Savannah, GA 31419, USA
| | - Soolim Jeong
- Neurovascular Physiology Laboratory, School of Kinesiology, Auburn University, Auburn, AL 36849, USA
| | - Austin T Robinson
- Neurovascular Physiology Laboratory, School of Kinesiology, Auburn University, Auburn, AL 36849, USA.
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13
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Kobetic MD, Burchell AE, Ratcliffe LEK, Neumann S, Adams ZH, Nolan R, Nightingale AK, Paton JFR, Hart EC. Sympathetic-transduction in untreated hypertension. J Hum Hypertens 2022; 36:24-31. [PMID: 34453103 PMCID: PMC8766277 DOI: 10.1038/s41371-021-00578-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 04/28/2021] [Accepted: 07/07/2021] [Indexed: 01/31/2023]
Abstract
Transduction of muscle sympathetic nerve activity (MSNA) into vascular tone varies with age and sex. Older normotensive men have reduced sympathetic transduction so that a given level of MSNA causes less arteriole vasoconstriction. Whether sympathetic transduction is altered in hypertension (HTN) is not known. We investigated whether sympathetic transduction is impaired in untreated hypertensive men compared to normotensive controls. Eight untreated hypertensive men and 10 normotensive men (age 50 ± 15 years vs. 45 ± 12 years (mean ± SD); p = 0.19, body mass index (BMI) 24.7 ± 2.7 kg/m2 vs. 26.0 ± 4.2 kg/m2; p = 0.21) were recruited. MSNA was recorded from the peroneal nerve using microneurography; beat-to-beat blood pressure (BP; Finapres) and heart rate (ECG) were recorded simultaneously at rest for 10 min. Sympathetic-transduction was quantified using a previously described method. The relationship between MSNA burst area and subsequent diastolic BP was measured for each participant with the slope of the regression indicating sympathetic transduction. MSNA was higher in the hypertensive group compared to normotensives (73 ± 17 bursts/100 heartbeats vs. 49 ± 19 bursts/100 heart bursts; p = 0.007). Sympathetic-transduction was lower in the hypertensive versus normotensive group (0.04%/mmHg/s vs. 0.11%/mmHg/s, respectively; R = 0.622; p = 0.006). In summary, hypertensive men had lower sympathetic transduction compared to normotensive individuals suggesting that higher levels of MSNA are needed to cause the same level of vasoconstrictor tone.
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Affiliation(s)
- Matthew D. Kobetic
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology, and Neuroscience, Clinical Research and Imaging Centre, University of Bristol, Bristol, UK
| | - Amy E. Burchell
- grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
| | - Laura E. K. Ratcliffe
- grid.415953.f0000 0004 0400 1537Department of Nephrology, Lister Hospital, East and North Hertfordshire NHS Trust, Hertfordshire, UK
| | - Sandra Neumann
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology, and Neuroscience, Clinical Research and Imaging Centre, University of Bristol, Bristol, UK ,grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
| | - Zoe H. Adams
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology, and Neuroscience, Clinical Research and Imaging Centre, University of Bristol, Bristol, UK ,grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
| | - Regina Nolan
- grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
| | - Angus K. Nightingale
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology, and Neuroscience, Clinical Research and Imaging Centre, University of Bristol, Bristol, UK ,grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
| | - Julian F. R. Paton
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology, and Neuroscience, Clinical Research and Imaging Centre, University of Bristol, Bristol, UK ,grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
| | - Emma C. Hart
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology, and Neuroscience, Clinical Research and Imaging Centre, University of Bristol, Bristol, UK ,grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
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14
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Robinson AT, Wenner MM, Charkoudian N. Differential influences of dietary sodium on blood pressure regulation based on race and sex. Auton Neurosci 2021; 236:102873. [PMID: 34509133 PMCID: PMC8627459 DOI: 10.1016/j.autneu.2021.102873] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 07/19/2021] [Accepted: 08/23/2021] [Indexed: 11/30/2022]
Abstract
There are clear differences between men and women, and differences among races, in the incidence and prevalence of hypertension. Furthermore, there is extensive inter-individual variability among humans in the extent to which sodium ingestion alters blood pressure. Orthostatic intolerance and orthostatic hypotension are more common in women; these are often treated with a high salt diet, which has variable efficacy in increasing blood volume and blood pressure. Conversely, people with certain forms of hypertension are often counseled to decrease their sodium intake. Non-Hispanic Black men and women have higher rates of hypertension compared to non-Hispanic White men and women and other racial/ethnic groups. In aggregate, Black women appear to have better orthostatic tolerance than White women. In the present paper, we summarize and evaluate the current evidence for mechanisms of blood pressure regulation in men and women, as well as differences between Black and White groups, with a focus on cardiovascular responses to salt and differences among these groups. We also provide a brief review of factors that are not traditionally considered to be "biological" - such as socio-economic disparities resulting from historic and contemporary inequity across racial groups. These non-biological factors have direct and substantial influences on cardiovascular mechanisms, as well as implications for the influences of salt and sodium intake on blood pressure and cardiovascular health. We conclude that both biological and socio-economic factors provide critical modulating influences when considering the impacts of sodium on cardiovascular health as functions of race and sex.
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Affiliation(s)
- Austin T Robinson
- Neurovascular Physiology Laboratory, School of Kinesiology, Auburn University, Auburn, AL 36849, United States of America.
| | - Megan M Wenner
- Women's Cardiovascular Research Laboratory, Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE 19713, United States of America
| | - Nisha Charkoudian
- Thermal & Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, MA 01760, United States of America
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15
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Reduced Endothelial Leptin Signaling Increases Vascular Adrenergic Reactivity in a Mouse Model of Congenital Generalized Lipodystrophy. Int J Mol Sci 2021; 22:ijms221910596. [PMID: 34638939 PMCID: PMC8508873 DOI: 10.3390/ijms221910596] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/20/2021] [Accepted: 09/27/2021] [Indexed: 01/19/2023] Open
Abstract
The adipokine leptin, which is best-known for its role in the control of metabolic function, is also a master regulator of cardiovascular function. While leptin has been approved for the treatment of metabolic disorders in patients with congenital generalized lipodystrophy (CGL), the effects of chronic leptin deficiency and the treatment on vascular contractility remain unknown. Herein, we investigated the effects of leptin deficiency and treatment (0.3 mg/day/7 days) on aortic contractility in male Berardinelli-Seip 2 gene deficient mice (gBscl2-/-, model of CGL) and their wild-type control (gBscl2+/+), as well as in mice with selective deficiency in endothelial leptin receptor (LepREC-/-). Lipodystrophy selectively increased vascular adrenergic contractility via NO-independent mechanisms and induced hypertrophic vascular remodeling. Leptin treatment and Nox1 inhibition blunted adrenergic hypercontractility in gBscl2-/- mice, however, leptin failed to rescue vascular media thickness. Selective deficiency in endothelial leptin receptor did not alter baseline adrenergic contractility but abolished leptin-mediated reduction in adrenergic contractility, supporting the contribution of endothelium-dependent mechanisms. These data reveal a new direct role for endothelial leptin receptors in the control of vascular contractility and homeostasis, and present leptin as a safe therapy for the treatment of vascular disease in CGL.
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16
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Abstract
OBJECTIVE Decades of research suggest that there may be important ethnic differences in the hemodynamic mechanisms that co-determine arterial blood pressure, the primary diagnostic index of hypertension. In general, studies have observed that, compared with European Americans (EAs), African Americans (AAs) exhibit higher total peripheral resistance (TPR), an important summative index of peripheral vascular constriction. In contrast, EAs have been reliably shown to exhibit greater cardiac output (CO), which is directly linked to left ventricle and overall cardiac blood flow. We have previously proposed that elevated basal TPR, in particular, represents one component of the cardiovascular conundrum, characterized, paradoxically, by elevated resting heart rate variability among AAs relative to EAs. The present meta-analysis and systematic review of the literature sought to extend this previous work by establishing the magnitude of the empirically implied ethnic differences in resting TPR and CO. METHODS A search of the literature yielded 140 abstracts on differences in TPR between AAs and EAs; 40 were included. Sample sizes, means, and standard deviations for baseline TPR with samples that included EAs and AAs were collected, and Hedges g was computed. RESULTS Findings indicated that AAs had higher baseline TPR than did EAs (Hedges g = 0.307, SE = 0.043, confidence interval= 0.224 to 0.391, p < .001). In addition, EAs had higher resting CO than did AAs (Hedges g = -0.214, SE = 0.056, confidence interval = -0.324 to -0.104, p < .001). CONCLUSIONS We discuss the present findings in the context of the role of elevated TPR in the deleterious effects of high blood pressure specifically for AAs.
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17
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Sapp RM, Chesney CA, Springer CB, Laskowski MR, Singer DB, Eagan LE, Mascone SE, Evans WS, Prior SJ, Hagberg JM, Ranadive SM. Race-specific changes in endothelial inflammation and microRNA in response to an acute inflammatory stimulus. Am J Physiol Heart Circ Physiol 2021; 320:H2371-H2384. [PMID: 33961505 DOI: 10.1152/ajpheart.00991.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Both aberrant vascular reactivity to acute cardiovascular stress and epigenetic mechanisms such as microRNA (miR) may underlie the increased propensity for African Americans (AA) to develop cardiovascular disease. This study assessed racial differences in acute induced endothelial inflammation and related miRs. Cultured human umbilical vein endothelial cells (HUVECs) derived from AA and Caucasian Americans (CA) were exposed to influenza vaccine to determine changes in inflammatory markers, endothelial nitric oxide synthase (eNOS), and miR expression/release. Endothelial function [flow-mediated dilation (FMD)], circulating IL-6, and circulating miR were also measured in young, healthy AA and CA individuals before and after receiving the influenza vaccine. There were no significant racial differences in any parameters at baseline. The vaccine induced increases in IL-6 release (24%, P = 0.02) and ICAM-1 mRNA (40%, P = 0.03), as well as reduced eNOS mRNA (24%, P = 0.04) in AA HUVECs, but not in CA HUVECs (all P > 0.05). Intracellular levels of anti-inflammatory miR-221-3p and miR-222-3p increased specifically in CA HUVECs (72% and 53%, P = 0.04 and P = 0.06), whereas others did not change in either race. HUVEC secretion of several miRs decreased in both races, whereas the release of anti-inflammatory miR-150-5p was decreased only by AA cells (-30%, P = 0.03). In individuals of both races, circulating IL-6 increased approximately twofold 24 h after vaccination (both P < 0.01) and returned to baseline levels by 48 h, whereas FMD remained unchanged. Although macrovascular function was unaffected by acute inflammation in AA and CA individuals, AA endothelial cells exhibited increased susceptibility to acute inflammation and unique changes in related miR.NEW & NOTEWORTHY Used as an acute inflammatory stimulus, the influenza vaccine induced an inflammatory response and decreased eNOS gene expression in endothelial cells derived from African Americans, but not Caucasian Americans. Race-specific changes in intracellular expression and release of specific microRNAs also occurred and may contribute to an exaggerated inflammatory response in African Americans. In vivo, the vaccine caused similar systemic inflammation but had no effect on endothelial function or circulating microRNAs in individuals of either race.
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Affiliation(s)
- Ryan M Sapp
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryland
| | - Catalina A Chesney
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryland
| | - Catherine B Springer
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryland
| | - Matthew R Laskowski
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland
| | - Daniel B Singer
- Department of Biology, University of Maryland, College Park, Maryland
| | - Lauren E Eagan
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryland
| | - Sara E Mascone
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryland
| | - William S Evans
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryland
| | - Steven J Prior
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryland.,Baltimore Veterans Affairs Geriatric Research, Education and Clinical Center, Baltimore, Maryland
| | - James M Hagberg
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryland
| | - Sushant M Ranadive
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, Maryland
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18
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Akins JD, Curtis BM, Patik JC, Olvera G, Nasirian A, Campbell JC, Shiva S, Brothers RM. Blunted hyperemic response to mental stress in young, non-Hispanic black men is not impacted by acute dietary nitrate supplementation. J Appl Physiol (1985) 2021; 130:1510-1521. [PMID: 33764167 DOI: 10.1152/japplphysiol.00453.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Non-Hispanic black individuals suffer from an elevated prevalence of hypertension and cardiovascular disease (CVD) relative to other populations. This elevated disease risk is, in large part, related to impaired vascular function, secondary to reduced nitric oxide (NO) bioavailability. Emerging evidence suggests that dietary nitrate supplementation improves several cardiovascular parameters, including vascular function, in part by increased NO bioavailability. However, whether these findings extend to a population of black individuals is unknown. This study tested the hypothesis that forearm blood flow responses in young, non-Hispanic, black (BL) men during a mental stress challenge would be blunted relative to young, non-Hispanic, white (WH) men. We further hypothesized that acute dietary nitrate supplementation would improve this response in BL men. This study comprised two parts (phase 1 and phase 2). Phase 1 investigated the difference in blood flow responses between young, BL, and WH men. In contrast, phase 2 investigated the effect of acute nitrate supplementation on the responses in a subset of the BL men from phase 1. Eleven (nine for phase 2) BL and eight WH men (23 ± 3 vs. 24 ± 4 yr, respectively) participated in this double-blind, placebo-controlled, randomized, crossover study. During each visit, hemodynamic responses during 3 min of mental stress were assessed in the brachial artery using duplex Doppler ultrasound. Phase 1 was completed in one visit, whereas phase 2 was completed over two visits separated by ∼1 wk. During phase 2, data were collected before and 2-h postconsumption of a beverage either high in nitrate content or nitrate depleted. In phase 1, peak forearm blood flow (FBF; P < 0.001), total FBF (P < 0.01), and forearm vascular conductance (FVC; P < 0.001) were blunted in the BL. During phase 2, prebeverage responses were similar to phase 1 and were unaffected following beverage consumption (P > 0.05 vs. prebeverage for all variables). These data indicate that young, BL men have blunted microvascular vasodilatory responses to acute mental stress, which may not be altered following acute nitrate supplementation.NEW & NOTEWORTHY This study tested the hypothesis that non-Hispanic black (BL) men have a blunted forearm hyperemic response to mental stress, which would be augmented following acute nitrate supplementation. The increase in forearm blood flow during mental stress was attenuated in BL men and was not impacted by nitrate supplementation. This supports findings of altered vascular function in this population. This is especially important as BL experience a higher prevalence of stress, which contributes to CVD risk.
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Affiliation(s)
- John D Akins
- Integrative Vascular Physiology Laboratory, Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
| | - Bryon M Curtis
- Integrative Vascular Physiology Laboratory, Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
| | - Jordan C Patik
- Integrative Vascular Physiology Laboratory, Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
| | - Guillermo Olvera
- Integrative Vascular Physiology Laboratory, Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
| | - Aida Nasirian
- Integrative Vascular Physiology Laboratory, Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
| | - Jeremiah C Campbell
- Integrative Vascular Physiology Laboratory, Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
| | - Sruti Shiva
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - R Matthew Brothers
- Integrative Vascular Physiology Laboratory, Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
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19
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Kaur J, Barbosa TC, Nandadeva D, Young BE, Stephens BY, Brothers RM, Fadel PJ. Attenuated Rapid-Onset Vasodilation to Forearm Muscle Contraction in Black Men. Med Sci Sports Exerc 2021; 53:590-596. [PMID: 32910095 PMCID: PMC7909956 DOI: 10.1249/mss.0000000000002511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
PURPOSE Non-Hispanic Black individuals have a blunted ability to vasodilate at rest compared with other racial groups. Limited studies have investigated blood flow responses to exercise in Black individuals. Recently, our laboratory demonstrated that Black men exhibit attenuated increases in forearm vascular conductance (FVC) during steady-state rhythmic handgrip. The mechanisms for this remain unknown. Herein, we used single muscle contractions, a modality that allows for assessment of rapid-onset vasodilation (ROV) independent of major elevations in shear stress, tissue metabolism, and systemic hemodynamics. METHODS Ten young, healthy Black and White men performed single forearm contractions at 20%, 40%, and 60% maximal voluntary contraction (MVC). In addition, cuff inflations were performed on the forearm to examine the contribution of mechanical compression to ROV. Forearm blood flow (FBF; duplex Doppler ultrasound), heart rate (ECG), and mean arterial pressure (Finometer) were continuously measured. FVC was calculated as FBF/mean arterial pressure. RESULTS Baseline FVC (White men vs Black men, 0.75 ± 0.11 vs 0.80 ± 0.09 mL·min-1·mm Hg-1; P = 0.73), FBF, and MVCs (White men vs Black men, 54 ± 2 vs 54 ± 2 kg; P = 0.95) were similar between the groups. After single contractions, both groups exhibited intensity-dependent FVC and FBF increases during ROV; however, these responses were attenuated in the Black group at all intensities (e.g., 60%MVC FVC: White men vs Black men, +371% ± 37% vs +220% ± 23% baseline; P = 0.001). FVC and FBF responses to cuff inflation alone were also attenuated in Black individuals (P < 0.001). CONCLUSIONS Collectively, these data indicate that Black men have an overall blunted ability to rapidly vasodilate compared with young White men.
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Affiliation(s)
- Jasdeep Kaur
- Department of Kinesiology, University of Texas at Arlington, Arlington, TX
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20
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Ojji D, Ale BM, Shedul L, Umuerri E, Ejim E, Alikor C, Agunyenwa C, Njideofor U, Eze H, Ansa V. The Effect of Nebivolol on Office Blood Pressure of Blacks Residing in Sub-Saharan Africa (A Pilot Study). Front Cardiovasc Med 2021; 7:613917. [PMID: 33505995 PMCID: PMC7829216 DOI: 10.3389/fcvm.2020.613917] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 11/30/2020] [Indexed: 11/13/2022] Open
Abstract
Introduction: There is substantial clinical evidence that monotherapy with beta-blockers are less effective in reducing blood pressure among hypertensive Black patients compared to Whites. The highly selective beta-1 agents like nebivolol and bisoprolol have, however, been reported to be effective in reducing blood pressure in African Americans. However, results in African Americans cannot be extrapolated to native Africans because of genetic admixture and gene-environment interaction. There is, therefore, the need for us to generate data that are applicable to Africans residing in sub-Saharan Africa. We therefore decided to evaluate the efficacy and tolerability of highly selective beta-1 agent nebivolol in hypertensive Black patients residing in sub-Saharan Africa. Materials and Methods: The nebivolol study was a multicenter, prospective, observational program among hypertensive patients with 4- and 8-week follow up which was conducted in 5 cities in Nigeria of Abuja, Calabar, Enugu, Oghara, and Port Harcourt. Dosages of nebivolol used in keeping with local prescribing information were 5 and 10 mg once daily each. The effectiveness of treatment was assessed by change from baseline in mean office systolic and diastolic blood pressures, and the proportion of patients achieving the therapeutic goal of <140/90 mmHg. Safety and tolerability of this medication were also assessed. Results: We report the results of the 140 patients studied. The mean age and body mass index were 46.9 ± 7.3 years and 22.3 ± 5.8 kg/m2, respectively, and 57.1% were female. Nebivolol reduced SBP and DBP by 7.6 and 6.6 mmHg, respectively, in 4 weeks, and by 11.1 and 8.0 mm Hg, respectively, in 8 weeks. Blood pressure control was achieved in 54.8% of the patients in 4 weeks and increased to 60.4% in 8 weeks. There was no change in metabolic profile between randomization and at 8 weeks, and erectile dysfunction occurred in 1.3% of the study population. Conclusions: Nebivolol 5 and 10 mg appear efficacious in Nigerian Africans with no negative metabolic effect and minimal side effect profile. Clinical Trial Registration: www.ClinicalTrials.gov, Study Identification: NCT03598673.
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Affiliation(s)
- Dike Ojji
- Department of Internal Medicine, Faculty of Clinical Sciences, College of Health Sciences, University of Abuja and University of Abuja Teaching Hospital, Gwagwalada, Nigeria.,Cardiovacular Research Unit, Department of Internal Medicine, University of Abuja and University of Abuja Teaching Hospital, Gwagwalada, Nigeria
| | | | - Lamkur Shedul
- Department of Family Medicine, University of Abuja Teaching Hospital, Gwagwalada, Nigeria
| | - Ejiroghene Umuerri
- Department of Internal Medicine, Faculty of Clinical Medicine, College of Health Sciences, Delta State University, Abraka, Nigeria.,Delta State University Teaching Hospital, Oghara, Nigeria
| | - Emmanuel Ejim
- Department of Internal Medicine, University of Nigeria and University of Nigeria Teaching Hospital, Enugu, Nigeria
| | - Chizindu Alikor
- Department of Internal Medicine, University of Port Harcourt and University of Port Harcourt Teaching, Port Harcourt, Nigeria
| | - Charles Agunyenwa
- Department of Internal Medicine, University of Nigeria and University of Nigeria Teaching Hospital, Enugu, Nigeria
| | - Uche Njideofor
- Department of Internal Medicine, University of Calabar and University of Calabar Teaching Hospital, Calabar, Nigeria
| | - Helen Eze
- Cardiovacular Research Unit, Department of Internal Medicine, University of Abuja and University of Abuja Teaching Hospital, Gwagwalada, Nigeria
| | - Victor Ansa
- Department of Internal Medicine, University of Calabar and University of Calabar Teaching Hospital, Calabar, Nigeria
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21
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Young BE, Greaney JL, Keller DM, Fadel PJ. Sympathetic transduction in humans: recent advances and methodological considerations. Am J Physiol Heart Circ Physiol 2021; 320:H942-H953. [PMID: 33416453 DOI: 10.1152/ajpheart.00926.2020] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Ever since their origin more than one half-century ago, microneurographic recordings of sympathetic nerve activity have significantly advanced our understanding of the generation and regulation of central sympathetic outflow in human health and disease. For example, it is now appreciated that a myriad of disease states exhibit chronic sympathetic overactivity, a significant predictor of cardiovascular morbidity and mortality. Although microneurographic recordings allow for the direct quantification of sympathetic outflow, they alone do not provide information with respect to the ensuing sympathetically mediated vasoconstriction and blood pressure (BP) response. Therefore, the study of vascular and/or BP responses to sympathetic outflow (i.e., sympathetic transduction) has now emerged as an area of growing interest within the field of neural cardiovascular control in human health and disease. To date, studies have primarily examined sympathetic transduction under two distinct paradigms: when reflexively evoking sympatho-excitation through the induction of a laboratory stressor (i.e., sympathetic transduction during stress) and/or following spontaneous bursts of sympathetic outflow occurring under resting conditions (i.e., sympathetic transduction at rest). The purpose of this brief review is to highlight how our physiological understanding of sympathetic transduction has been advanced by these studies and to evaluate the primary analytical techniques developed to study sympathetic transduction in humans. We also discuss the framework by which the assessment of sympathetic transduction during stress reflects a fundamentally different process relative to sympathetic transduction at rest and why findings from investigations using these different techniques should be interpreted as such and not necessarily be considered one and the same.
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Affiliation(s)
- Benjamin E Young
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas
| | - Jody L Greaney
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas
| | - David M Keller
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas
| | - Paul J Fadel
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas
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22
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Jeong JH, Brown ML, Kapuku G, Harshfield GA, Park J. α-Adrenergic receptor blockade attenuates pressor response during mental stress in young black adults. Physiol Rep 2021; 8:e14642. [PMID: 33356011 PMCID: PMC7757373 DOI: 10.14814/phy2.14642] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/13/2020] [Accepted: 10/19/2020] [Indexed: 12/11/2022] Open
Abstract
Black individuals exhibit increased blood pressure (BP) responses to sympathetic stimulation that are associated with an increased risk of hypertension (HTN). We tested the hypothesis that α1 -adrenergic blockade inhibits the increased BP response during and after 45-min stress in young normotensive Black adults, which may be mediated, in part, by dampened vasoconstriction and decreased renal sodium retention. Utilizing a double-masked randomized, crossover study design, 51 normotensive Black adults (31 ± 8 yr) were treated with either a placebo or 1 mg/day of prazosin for 1 week. On the final day of each treatment, hemodynamic measures and urinary sodium excretion (UNaV) were collected before (Rest), during (Stress) and after (Recovery) 45 min of mental stress induced via a competitive video game task. During the Stress period, diastolic BP and total peripheral resistance (TPR) were significantly lower with prazosin compared to placebo (p < .05 for both). Similarly, we observed lower systolic BP, diastolic BP, and TPR during the Recovery period with prazosin versus placebo (p < .05 for both). There was no effect of prazosin on stress-associated UNaV. The change in systolic BP from Rest to Recovery was positively associated with the change in TPR with both treatments (p < .05 for both). In summary, prazosin treatment dampened BP reactivity to 45-min mental stress and lowered post-stress BP over the recovery period, which was linked to reduce TPR in young normotensive Black adults. These results suggest that α1 -adrenergic receptor activity may contribute to BP responses and delayed BP recovery to prolonged mental stress through increased vasoconstriction in Black adults.
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Affiliation(s)
- Jin Hee Jeong
- Department of MedicineGeorgia Prevention InstituteMedical College of GeorgiaAugusta UniversityAugustaGAUSA
- Division of Renal MedicineDepartment of MedicineEmory UniversityAtlantaGAUSA
- Department of Veterans Affairs Health Care SystemDecaturGAUSA
| | - Michelle L. Brown
- Department of MedicineGeorgia Prevention InstituteMedical College of GeorgiaAugusta UniversityAugustaGAUSA
| | - Gaston Kapuku
- Department of MedicineGeorgia Prevention InstituteMedical College of GeorgiaAugusta UniversityAugustaGAUSA
| | - Gregory A. Harshfield
- Department of MedicineGeorgia Prevention InstituteMedical College of GeorgiaAugusta UniversityAugustaGAUSA
| | - Jeanie Park
- Division of Renal MedicineDepartment of MedicineEmory UniversityAtlantaGAUSA
- Department of Veterans Affairs Health Care SystemDecaturGAUSA
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23
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Hartwig CL, Sprick JD, Jeong J, Hu Y, Morison DG, Stein CM, Paranjape S, Park J. Increased vascular α1-adrenergic receptor sensitivity in older adults with posttraumatic stress disorder. Am J Physiol Regul Integr Comp Physiol 2020; 319:R611-R616. [PMID: 32966119 DOI: 10.1152/ajpregu.00155.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Posttraumatic stress disorder (PTSD) is an independent risk factor for the development of hypertension and cardiovascular disease. Patients with PTSD have heightened blood pressure and sympathetic nervous system reactivity; however, it is unclear if patients with PTSD have exaggerated vasoconstriction in response to sympathetic nerve activation that could also contribute to increased blood pressure reactivity. Therefore, we hypothesized that patients with PTSD have increased sensitivity of vascular α1-adrenergic receptors (α1ARs), the major mediators of vasoconstriction in response to release of norepinephrine at sympathetic nerve terminals. To assess vascular α1AR sensitivity, we measured the degree of venoconstriction in a dorsal hand vein in response to exponentially increasing doses of the selective α1AR agonist, phenylephrine (PE), in 9 patients with PTSD (age = 59 ± 2 yr) and 10 age-matched controls (age = 60 ± 1 yr). Individual dose-response curves were generated to determine the dose of PE that induces 50% of maximal venoconstriction (i.e., PE ED50) reflective of vascular α1AR sensitivity. In support of our hypothesis, PE ED50 values were lower in PTSD compared with controls (245 ± 54 ng/min vs. 1,995 ± 459 ng/min, P = 0.012), indicating increased vascular α1AR sensitivity in PTSD. The PTSD group also had an increase in slope of rise in venoconstriction, indicative of an altered venoconstrictive reactivity to PE compared with controls (19.8% ± 1.2% vs. 15.1% ± 1.2%, P = 0.009). Heightened vascular α1AR sensitivity in PTSD may contribute to augmented vasoconstriction and blood pressure reactivity to sympathoexcitation and to increased cardiovascular disease risk in this patient population.
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Affiliation(s)
- Cortnie L Hartwig
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Health Care System, Decatur, Georgia
| | - Justin D Sprick
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Health Care System, Decatur, Georgia
| | - Jinhee Jeong
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Health Care System, Decatur, Georgia
| | - Yingtian Hu
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - Doree G Morison
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Health Care System, Decatur, Georgia
| | - C Michael Stein
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Sachin Paranjape
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Jeanie Park
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Health Care System, Decatur, Georgia
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24
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Wolf ST, Jablonski NG, Kenney WL. Examining "race" in physiology. Am J Physiol Heart Circ Physiol 2020; 319:H1409-H1413. [PMID: 33064554 PMCID: PMC7792710 DOI: 10.1152/ajpheart.00698.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/21/2020] [Accepted: 10/11/2020] [Indexed: 12/17/2022]
Abstract
Racial disparities in cardiovascular and cerebrovascular health outcomes are well described, and recent research has shed light on the mechanistic underpinnings of those disparities. However, "race" is a social construct that is poorly defined and continually evolving and is historically based on faulty premises. The continued categorization by race in physiological research suggests that there are inherent differences between races, rather than addressing the specific underlying factors that result in health disparities between groups. The purpose of this Perspectives article is to provide a brief history of the genesis of categorization by race, why such categorization should be reconsidered in physiology research, and offer recommendations to more directly investigate the underlying factors that result in group disparities in cardiovascular and cerebrovascular health.
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Affiliation(s)
- S Tony Wolf
- Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania
| | - Nina G Jablonski
- Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania
| | - W Larry Kenney
- Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania
- Graduate Program in Physiology, The Pennsylvania State University, University Park, Pennsylvania
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25
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Miller JT, Turner CG, Otis JS, Sebeh Y, Hayat MJ, Quyyumi AA, Wong BJ. Inhibition of iNOS augments cutaneous endothelial NO-dependent vasodilation in prehypertensive non-Hispanic Whites and in non-Hispanic Blacks. Am J Physiol Heart Circ Physiol 2020; 320:H190-H199. [PMID: 33124886 DOI: 10.1152/ajpheart.00644.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
We tested the hypothesis that inducible nitric oxide synthase (iNOS) contributes to reduced nitric oxide (NO)-dependent vasodilation in non-Hispanic Blacks and prehypertensive non-Hispanic Whites. Twenty Black and twenty White participants (10 normotensive, 10 prehypertensive per group; n = 40 total) participated in this study. Participants were instrumented with two microdialysis fibers, and each site was randomized as control (lactated Ringer) or iNOS inhibition (0.1 mM 1400W). Laser-Doppler flow probes and local heaters were used to measure skin blood flow and heat the skin to induce vasodilation, respectively. Each site was heated from 33°C to 39°C (rate: 0.1°C/s). Once a plateau was established, 20 mM nitro-l-arginine methyl ester (l-NAME), a nonspecific NOS inhibitor, was infused at each site to quantify NO-dependent vasodilation. At control sites, %NO-dependent vasodilation was reduced in prehypertensive Whites (47 ± 10%NO) and in both normotensive and prehypertensive Blacks (39 ± 9%NO and 28 ± 5%NO, respectively) relative to normotensive Whites (73 ± 8%NO; P < 0.0001 for all comparisons). Compared with respective control sites, iNOS inhibition increased NO-dependent vasodilation in prehypertensive Whites (68 ± 8%NO) and in both normotensive and prehypertensive Blacks (78 ± 8%NO and 55 ± 6%NO, respectively; P < 0.0001 for all comparisons). We failed to find an effect for normotensive Whites (77 ± 7%NO). After iNOS inhibition, %NO-dependent vasodilation was similar between normotensive Whites, prehypertensive Whites, and normotensive Blacks. Inhibition of iNOS increased NO-dependent vasodilation to a lesser extent in prehypertensive Blacks. These data suggest that iNOS contributes to reduced NO-dependent vasodilation in prehypertension and in Black participants.NEW & NOTEWORTHY Inducible nitric oxide synthase (iNOS) is typically upregulated in conditions of increased oxidative stress and may have detrimental effects on the vasculature. Endothelial nitric oxide (NO), which is cardioprotective, is reduced in prehypertensive non-Hispanic Whites and in non-Hispanic Blacks. We found that inhibition of iNOS can increase endothelial NO-dependent vasodilation in prehypertensive White participants and in both normotensive and prehypertensive Black participants.Inducible nitric oxide (NO) synthase (iNOS) can be upregulated under conditions of increased oxidative stress and may have detrimental effects on the vasculature. Endothelial NO, which is cardioprotective, is reduced in prehypertensive non-Hispanic Whites and in non-Hispanic Blacks. We found that inhibition of iNOS can increase endothelial NO-dependent vasodilation in prehypertensive White participants and in both normotensive and prehypertensive Black participants.
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Affiliation(s)
- James T Miller
- Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia
| | - Casey G Turner
- Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia
| | - Jeffrey S Otis
- Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia
| | - Yesser Sebeh
- School of Public Health, Georgia State University, Atlanta, Georgia
| | - Matthew J Hayat
- School of Public Health, Georgia State University, Atlanta, Georgia
| | - Arshed A Quyyumi
- Emory Clinical Cardiovascular Research Institute, Emory University School of Medicine, Atlanta, Georgia
| | - Brett J Wong
- Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia
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26
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Farrell MC, Giza RJ, Shibao CA. Race and sex differences in cardiovascular autonomic regulation. Clin Auton Res 2020; 30:371-379. [PMID: 32894376 PMCID: PMC7584374 DOI: 10.1007/s10286-020-00723-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/19/2020] [Indexed: 12/17/2022]
Abstract
Racial and ethnic differences in cardiovascular morbidity and mortality persist despite advances in risk factor identification and implementation of evidence-based treatment strategies. African American men and women are disproportionately affected by cardiovascular risk factors, particularly hypertension. In this context, previous studies have identified sex and racial differences in autonomic cardiovascular regulation which may contribute to the development of hypertension and its high morbidity burden among African Americans. In this review, we provide a comprehensive evaluation of the potential pathophysiological mechanisms of blood pressure control and their differences based on sex and race. These mechanisms include obesity-induced sympathetic activation, sympatho-vascular transduction, baroreflex sensitivity and adrenoreceptor vascular sensitivity, which have been the subjects of prior investigation in this field. Understanding the racial differences in the pathophysiology of hypertension and its co-morbid conditions would allow us to implement better treatment strategies tailored to African Americans, with the ultimate goal of reducing cardiovascular mortality in this population.
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Affiliation(s)
| | - Richard J Giza
- Drexel University College of Medicine, Philadelphia, PA, USA
| | - Cyndya A Shibao
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt Autonomic Dysfunction Center, Vanderbilt University Medical Center, 506 Robinson Research Building, Nashville, TN, 37232-6602, USA.
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27
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Brothers RM, Stephens BY, Akins JD, Fadel PJ. Influence of sex on heightened vasoconstrictor mechanisms in the non-Hispanic black population. FASEB J 2020; 34:14073-14082. [PMID: 32949436 DOI: 10.1096/fj.202001405r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/20/2020] [Accepted: 08/27/2020] [Indexed: 11/11/2022]
Abstract
Cardiovascular disease (CVD) affects individuals of all races and ethnicities; however, its prevalence is highest in non-Hispanic black individuals (BL) relative to other populations. While previous research has provided valuable insight into elevated CVD risk in the BL population, this work has been almost exclusively conducted in men. This is alarming given that BL women suffer from CVD at an equivalent rate to BL men and each has a greater prevalence when compared to all other ethnicities, regardless of sex. The importance of investigating sex differences in mechanisms of cardiovascular function is highlighted by the National Institute of Health requiring sex to be considered as a biological variable in research studies to better our "understanding of key sex influences on health processes and outcomes." The mechanism(s) responsible for the elevated CVD risk in BL women remains unclear and is likely multifactorial. Limited studies in BL women suggest that, while impaired vasodilator capacity is involved, heightened vasoconstrictor tone and/or responsiveness may also contribute. Within this mini-review, we will discuss potential mechanisms of elevated rates of hypertension and other CVDs in BL individuals with a particular focus on young, otherwise healthy, college-aged women. To stimulate academic thought and future research, we will also discuss potential mechanisms for impaired vascular function in BL women, as well as possible divergent mechanisms between BL men and women based on either preliminary data or plausible speculation extending from findings in the existing literature. Last, we will conclude with potential future research directions aimed at better understanding the elevated risk for hypertension and CVD in BL women.
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Affiliation(s)
| | | | - John D Akins
- Department of Kinesiology, University of Texas, Arlington, TX, USA
| | - Paul J Fadel
- Department of Kinesiology, University of Texas, Arlington, TX, USA
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28
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Barbosa TC, Young BE, Stephens BY, Nandadeva D, Kaur J, Keller DM, Fadel PJ. Functional sympatholysis is preserved in healthy young Black men during rhythmic handgrip exercise. Am J Physiol Regul Integr Comp Physiol 2020; 319:R323-R328. [PMID: 32783690 DOI: 10.1152/ajpregu.00105.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Black men have attenuated increases in forearm vascular conductance (FVC) and forearm blood flow (FBF) during moderate- and high-intensity rhythmic handgrip exercise compared with White men, but the underlying mechanisms are unclear. Here, we tested for the first time the hypothesis that functional sympatholysis (i.e., attenuation of sympathetic vasoconstriction in the exercising muscles) is impaired in Black men compared with White men. Thirteen White and 14 Black healthy young men were studied. FBF (duplex Doppler ultrasound) and mean arterial pressure (MAP; Finometer) were measured at rest and during rhythmic handgrip exercise at 30% maximal voluntary contraction. FVC was calculated as FBF/MAP. Sympathetic activation was induced via lower body negative pressure (LBNP) at -20 Torr for 2 min at rest and from the 3rd to the 5th min of handgrip. Sympathetic vasoconstriction was assessed as percent reductions in FVC during LBNP. The groups presented similar resting FVC, FBF, and MAP. During LBNP at rest, reductions in FVC were not different between White (-35 ± 10%) and Black men (-32 ± 14%, P = 0.616), indicating similar reflex-induced sympathetic vasoconstriction. During handgrip exercise, there were minimal reductions in FVC with LBNP in either group (White: -1 ± 7%; Black: +1 ± 8%; P = 0.523), indicating functional sympatholysis in both groups. Thus, contrary to our hypothesis, our findings indicate a preserved functional sympatholysis in healthy young Black men compared with White men, suggesting that this mechanism does not appear to contribute to reduced exercise hyperemia during moderate-intensity rhythmic handgrip in this population.
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Affiliation(s)
- Thales C Barbosa
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
| | - Benjamin E Young
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
| | - Brandi Y Stephens
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
| | - Damsara Nandadeva
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
| | - Jasdeep Kaur
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
| | - David M Keller
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
| | - Paul J Fadel
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas
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29
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Young BE, Kaur J, Vranish JR, Stephens BY, Barbosa TC, Cloud JN, Wang J, Keller DM, Fadel PJ. Augmented resting beat-to-beat blood pressure variability in young, healthy, non-Hispanic black men. Exp Physiol 2020; 105:1102-1110. [PMID: 32362031 DOI: 10.1113/ep088535] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 04/24/2020] [Indexed: 12/21/2022]
Abstract
NEW FINDINGS What is the central question of this study? The prevalence of hypertension in black individuals exceeds that in other racial groups. Despite this well-known heightened risk, the underlying contributory factors remain incompletely understood. We hypothesized that young black men would exhibit augmented beat-to-beat blood pressure variability compared with white men and that black men would exhibit augmented total peripheral resistance variability. What is the main finding and its importance? We demonstrate that young, healthy black men exhibit greater resting beat-to-beat blood pressure variability compared with their white counterparts, which is accompanied by greater variability in total peripheral resistance. These swings in blood pressure over time might contribute to the enhanced cardiovascular risk profile in black individuals. ABSTRACT The prevalence of hypertension in black (BL) individuals exceeds that in other racial groups. Recently, resting beat-to-beat blood pressure (BP) variability has been shown to predict cardiovascular risk and detect target organ damage better than ambulatory BP monitoring. Given the heightened risk in BL individuals, we hypothesized young BL men would exhibit augmented beat-to-beat BP variability compared with white (WH) men. Furthermore, given studies reporting reduced vasodilatation and augmented vasoconstriction in BL individuals, we hypothesized that BL men would exhibit augmented variability in total peripheral resistance (TPR). In 45 normotensive men (24 BL), beat-to-beat BP (Finometer) was measured during 10-20 min of quiet rest. Cardiac output and TPR were estimated (Modelflow method). Despite similar resting BP, BL men exhibited greater BP standard deviation (e.g. systolic BP SD; BL, 7.1 ± 2.2 mmHg; WH, 5.4 ± 1.5 mmHg; P = 0.006) compared with WH men, which was accompanied by a greater TPR SD (P = 0.003), but not cardiac output SD (P = 0.390). Other traditional measures of variability provided similar results. Histogram analysis indicated that BL men exhibited a greater percentage of cardiac cycles with BPs higher (> +10 mmHg higher) and lower (< -8 mmHg lower) than mean systolic BP compared with WH men (interaction, P < 0.001), which was accompanied by a greater percentage of cardiac cycles with high/low TPR (P < 0.001). In a subset of subjects (n = 30), reduced sympathetic baroreflex sensitivity was associated with augmented BP variability (r = -0.638, P < 0.001), whereas cardiac baroreflex sensitivity had no relationship (P = 0.447). Herein, we document an augmented beat-to-beat BP variability in young BL men, which coincided with fluctuations in vascular resistance and reduced sympathetic BRS.
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Affiliation(s)
- Benjamin E Young
- Department of Kinesiology, University of Texas at Arlington, Arlington, TX, USA
| | - Jasdeep Kaur
- Department of Kinesiology, University of Texas at Arlington, Arlington, TX, USA
| | - Jennifer R Vranish
- Department of Integrative Physiology and Health Science, Alma College, Alma, MI, USA
| | - Brandi Y Stephens
- Department of Kinesiology, University of Texas at Arlington, Arlington, TX, USA
| | - Thales C Barbosa
- Department of Kinesiology, University of Texas at Arlington, Arlington, TX, USA
| | - Jane N Cloud
- Department of Kinesiology, University of Texas at Arlington, Arlington, TX, USA
| | - Jing Wang
- College of Nursing, University of Texas at Arlington, Arlington, TX, USA
| | - David M Keller
- Department of Kinesiology, University of Texas at Arlington, Arlington, TX, USA
| | - Paul J Fadel
- Department of Kinesiology, University of Texas at Arlington, Arlington, TX, USA
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30
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Drew RC, Charkoudian N, Park J. Neural control of cardiovascular function in black adults: implications for racial differences in autonomic regulation. Am J Physiol Regul Integr Comp Physiol 2019; 318:R234-R244. [PMID: 31823675 DOI: 10.1152/ajpregu.00091.2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Black adults are at increased risk for developing hypertension and cardiovascular and chronic kidney disease and have greater associated morbidity/mortality than white adults who are otherwise demographically similar. Despite the key role of the autonomic nervous system in the regulation of cardiovascular function, the mechanistic contributions of sympathetic nerves to racial differences in cardiovascular dysfunction and disease remain poorly understood. In this review, we present an update and synthesis of current understanding regarding the roles of autonomic neural mechanisms in normal and pathophysiological cardiovascular control in black and white adults. At rest, many hemodynamic and autonomic variables, including blood pressure, cardiac output, and sympathetic nerve activity, are similar in healthy black and white adults. However, resting sympathetic vascular transduction and carotid baroreflex responses are altered in ways that tend to promote increased vasoconstriction and higher blood pressure, even in healthy, normotensive black adults. Acute sympathoexcitatory maneuvers, including exercise and cold pressor test, often result in augmented sympathetic and hemodynamic responses in healthy black adults. Clinically, although mechanistic evidence is scarce in this area, existing data support the idea that excessive sympathetic activation and/or transduction into peripheral vasoconstriction contribute importantly to the pathophysiology of hypertension and chronic kidney disease in black compared with white adults. Important areas for future work include more detailed study of sympathetic and hemodynamic reactivity to exercise and other stressors in male and female black adults and, particularly, sympathetic control of renal function, an important area of clinical concern in black patients.
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Affiliation(s)
- Rachel C Drew
- Department of Exercise and Health Sciences, University of Massachusetts Boston, Boston, Massachusetts
| | - Nisha Charkoudian
- Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Jeanie Park
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.,Atlanta Veterans Affairs Health Care System, Decatur, Georgia
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Goessler KF, Peçanha T. A call for attention: Is it time to revise the exercise guidelines for hypertension in African and Asian populations? Eur J Prev Cardiol 2019; 27:455-456. [PMID: 31490088 DOI: 10.1177/2047487319874896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Karla F Goessler
- Department of Physical Education, Filadelfia University Center, Brazil
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32
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Brothers RM, Fadel PJ, Keller DM. Racial disparities in cardiovascular disease risk: mechanisms of vascular dysfunction. Am J Physiol Heart Circ Physiol 2019; 317:H777-H789. [PMID: 31397168 DOI: 10.1152/ajpheart.00126.2019] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cardiovascular disease (CVD) accounts for a third of all deaths in the United States making it the leading cause of morbidity and mortality. Although CVD affects individuals of all races/ethnicities, the prevalence of CVD is highest in non-Hispanic black (BL) individuals relative to other populations. The mechanism(s) responsible for elevated CVD risk in the BL population remains incompletely understood. However, impaired vascular vasodilator capacity and exaggerated vascular vasoconstrictor responsiveness are likely contributing factors, both of which are present even in young, otherwise healthy BL individuals. Within this review, we highlight some historical and recent data, collected from our laboratories, of impaired vascular function, in terms of reduced vasodilator capacity and heightened vasoconstrictor responsiveness, in the peripheral and cerebral circulations in BL individuals. We provide data that such impairments may be related to elevated oxidative stress and subsequent reduction in nitric oxide bioavailability. In addition, divergent mechanisms of impaired vasodilatory capacity between BL men and women are discussed. Finally, we propose several directions where future research is needed to fill in knowledge gaps, which will allow for better understanding of the mechanisms contributing to impaired vascular function in this population. Ultimately, this information will allow for better lifestyle and therapeutic approaches to be implemented in an effort to minimize the increased CVD burden in the BL population.
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Affiliation(s)
- R Matthew Brothers
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas
| | - Paul J Fadel
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas
| | - David M Keller
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas
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Sprick JD, Morison DL, Stein CM, Li Y, Paranjape S, Fonkoue IT, DaCosta DR, Park J. Vascular α 1-adrenergic sensitivity is enhanced in chronic kidney disease. Am J Physiol Regul Integr Comp Physiol 2019; 317:R485-R490. [PMID: 31314543 DOI: 10.1152/ajpregu.00090.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Chronic kidney disease (CKD) is often complicated by difficult-to-control hypertension, in part due to chronic overactivation of the sympathetic nervous system (SNS). CKD patients also exhibit a greater increase in arterial blood pressure for a given increase in sympathetic nerve activation, suggesting an augmented vasoconstrictive response to SNS activation (i.e., neurovascular transduction). One potential mechanism of increased sympathetic neurovascular transduction is heightened sensitivity of the vascular α1-adrenergic receptors (α1ARs), the major effectors of vasoconstriction in response to norepinephrine release at the sympathetic nerve terminals. Therefore, we hypothesized that patients with CKD have increased vascular α1AR sensitivity. We studied 32 patients with CKD stages III and IV (age 59.9 ± 1.3 yr) and 19 age-matched controls (CON, age 63.2 ± 1.6 yr). Using a linear variable differential transformer (LVDT), we measured change in venoconstriction in response to exponentially increasing doses of the selective α1AR agonist phenylephrine (PE) administered sequentially into a dorsal hand vein. Individual semilogarithmic PE dose-response curves were constructed for each participant to determine the PE dose at which 50% of maximum venoconstriction occurred (ED50), reflecting α1AR sensitivity. In support of our hypothesis, CKD patients had a lower PE ED50 than CON (CKD = 2.23 ± 0.11 vs. CON = 2.63 ± 0.20, P = 0.023), demonstrating increased vascular α1AR sensitivity. Additionally, CKD patients had a greater venoconstrictive capacity to PE than CON (P = 0.015). Augmented α1AR sensitivity may contribute mechanistically to enhanced neurovascular transduction in CKD and may explain, in part, the greater blood pressure reactivity exhibited in these patients.
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Affiliation(s)
- Justin D Sprick
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Health Care System, Decatur, Georgia
| | - Doree L Morison
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Health Care System, Decatur, Georgia
| | - C Michael Stein
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Yunxiao Li
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - Sachin Paranjape
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Ida T Fonkoue
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Health Care System, Decatur, Georgia
| | - Dana R DaCosta
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Health Care System, Decatur, Georgia
| | - Jeanie Park
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Health Care System, Decatur, Georgia
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Myburgh C, Huisman HW, Mels CMC. Cardiovascular reactivity and oxidative stress in young and older adults: the African-PREDICT and SABPA studies. Blood Press 2019; 28:229-238. [PMID: 31030564 DOI: 10.1080/08037051.2019.1609348] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Background: Oxidative stress and increased cardiovascular reactivity are associated with endothelial dysfunction and cardiovascular disease development. These factors along with early vascular compromise are more pronounced in black populations. We aimed to compare cardiovascular reactivity and investigate associations thereof with oxidative stress in two bi-ethnic cohorts (younger: 25.0 ± 3.19yrs; older: 44.7 ± 9.61yrs). Methods: Cardiovascular reactivity using the color-word conflict test was measured with the Finometer device. Oxidative stress markers included superoxide dismutase (SOD), γ-glutamyl transferase (γ-GT) and reactive oxygen species (ROS). Results: Black groups displayed greater cardiovascular responses to stress than white groups. In younger white participants, diastolic blood pressure (DBP) (β = 0.31; p = 0.001) and mean arterial blood pressure (MAP) (β = 0.28; p = 0.002) associated with ROS. In older black participants, DBP (β = 0.23; p = 0.009), MAP (β = 0.18; p = 0.033), stroke volume (β = -0.20; p = 0.023) and arterial compliance (β = -0.25; p = 0.005) associated with γ-GT. In older white participants, systolic blood pressure (β = -0.20; p = 0.006) and MAP (β = -0.19; p = 0.009) associated with SOD. Conclusions: In the older black group, cardiovascular reactivity associated with markers of glutathione metabolism, suggesting a possible compensatory up-regulation thereof in order to correct their heightened responses to stress. Independent of age, findings in the white groups support a regulatory role of ROS to maintain vascular tone during stress.
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Affiliation(s)
- Caitlynd Myburgh
- a Hypertension in Africa Research Team (HART) , North-West University , Potchefstroom , South Africa.,b University of South Africa (UNISA) , Roodepoort , South Africa
| | - Hugo W Huisman
- a Hypertension in Africa Research Team (HART) , North-West University , Potchefstroom , South Africa.,c MRC Research Unit for Hypertension and Cardiovascular Disease , North-West University , Potchefstroom , South Africa
| | - Catharina M C Mels
- a Hypertension in Africa Research Team (HART) , North-West University , Potchefstroom , South Africa.,c MRC Research Unit for Hypertension and Cardiovascular Disease , North-West University , Potchefstroom , South Africa
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35
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Carnevali L, Ottaviani C, Williams DP, Kapuku G, Thayer JF, Hill LK. Hemodynamic profile and compensation deficit in African and European Americans during physical and mental stress. Biol Psychol 2018; 141:17-24. [PMID: 30599210 DOI: 10.1016/j.biopsycho.2018.12.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 11/09/2018] [Accepted: 12/05/2018] [Indexed: 12/21/2022]
Abstract
Increased vascular reactivity to stress has been suggested to contribute to the greater risk for developing hypertension in African Americans. Here, we examined the way (hemodynamic profile) and the extent to which (compensation deficit) cardiac output and total peripheral resistance compensate for each other in determining blood pressure responses to a physical (orthostasis) and a mental (anger recall) stress task, in normotensive African American (AA, n = 30) and European American (EA, n = 48) college students. Blood pressure stress reactivity did not differ as a function of race. However, AAs showed a prominent vascular hemodynamic profile and a significant compensation deficit in response to both tasks, while EAs showed no hemodynamic response to orthostasis and a mixed profile in response to anger recall. The present findings demonstrate a more prominent vascular hemodynamic reactivity to stress in AAs, which could contribute to the pathogenesis of hypertension in this ethnic group.
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Affiliation(s)
- Luca Carnevali
- Stress Physiology Lab, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy.
| | | | | | - Gaston Kapuku
- Department of Population Health Sciences, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Julian F Thayer
- Department of Psychology, The Ohio State University, Columbus, OH, USA
| | - LaBarron K Hill
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA; Center for Biobehavioral Health Disparities Research, Duke University, Durham, NC, USA; Center for the Study of Aging and Human Development, Duke University, Durham, NC, USA
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36
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van Laer SD, Snijder MB, Agyemang C, Peters RJ, van den Born BJH. Ethnic differences in hypertension prevalence and contributing determinants - the HELIUS study. Eur J Prev Cardiol 2018; 25:1914-1922. [PMID: 30296837 DOI: 10.1177/2047487318803241] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
AIMS There are important ethnic differences in the prevalence of hypertension and hypertension-mediated cardiovascular complications, but there is ongoing debate on the nature of these differences. We assessed the contribution of lifestyle, socio-economic and psychosocial variables to ethnic differences in hypertension prevalence. METHODS We used cross-sectional data from the Healthy Life In an Urban Setting (HELIUS) study, including 21,520 participants aged 18-70 years of South-Asian Surinamese ( n = 3032), African Surinamese ( n = 4124), Ghanaian ( n = 2331), Turkish ( n = 3594), Moroccan ( n = 3891) and Dutch ( n = 4548) ethnic origin. Ethnic differences in hypertension prevalence rates were examined using logistic regression models. RESULTS After adjustment for a broad range of variables, significant higher hypertension prevalence compared to the Dutch population remained in Ghanaian men (odds ratio 2.62 (95% confidence interval 2.14-3.22)) and women (4.16 (3.39-5.12)), African Surinamese men (1.62 (1.37-1.92)) and women (2.70 (2.29-3.17)) and South-Asian Surinamese men (1.22 (1.15-1.46)) and women (1.84 (1.53-2.22)). In contrast, Turkish men (0.72 (0.60-0.87)) and Moroccan men (0.50 (0.41-0.61)) and women (0.57 (0.46-0.71)) had a lower hypertension prevalence compared with the Dutch population. The differences in hypertension prevalence were present across different age groups and persisted after stratification for body mass index and waist-to-hip ratio. CONCLUSION Large ethnic differences in hypertension prevalence exist that are already present in young adulthood. Adjustment for common variables known to be associated with a higher risk of hypertension explained the higher adjusted prevalence rates among Turks and Moroccans, but not in African and South-Asian descent populations who remained to have a higher rate of hypertension compared to the Dutch host population.
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Affiliation(s)
- Stag D van Laer
- 1 Department of Internal and Vascular Medicine, Academic Medical Center, the Netherlands
| | - Marieke B Snijder
- 2 Department of Public Health, Amsterdam Public Health Research Institute, the Netherlands.,3 Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Amsterdam Public Health Research Institute, the Netherlands
| | - Charles Agyemang
- 2 Department of Public Health, Amsterdam Public Health Research Institute, the Netherlands
| | - Ron Jg Peters
- 4 Department of Cardiology, Academic Medical Center, the Netherlands
| | - Bert-Jan H van den Born
- 1 Department of Internal and Vascular Medicine, Academic Medical Center, the Netherlands.,2 Department of Public Health, Amsterdam Public Health Research Institute, the Netherlands
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37
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Barbosa TC, Kaur J, Stephens BY, Akins JD, Keller DM, Brothers RM, Fadel PJ. Attenuated forearm vascular conductance responses to rhythmic handgrip in young African-American compared with Caucasian-American men. Am J Physiol Heart Circ Physiol 2018; 315:H1316-H1321. [PMID: 30118345 DOI: 10.1152/ajpheart.00387.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Previous studies have demonstrated that African-American (AA) individuals have heightened vasoconstrictor and reduced vasodilator responses under resting conditions compared with Caucasian-American (CA) individuals. However, potential differences in vascular responses to exercise remain unclear. Therefore, we tested the hypothesis that, compared with CA subjects, AA subjects would present an attenuated increase in forearm vascular conductance (FVC) during rhythmic handgrip exercise. Forearm blood flow (FBF; duplex Doppler ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured in healthy young CA ( n = 10) and AA ( n = 10) men during six trials of rhythmic handgrip performed at workloads of 4, 8, 12, 16, 20, and 24 kg. FVC (calculated as FBF/MAP), FBF, and MAP were similar between groups at rest (FVC: 63 ± 7 ml·min-1·100 mmHg-1 in CA subjects vs. 62 ± 7 ml·min-1·100 mmHg-1 in AA subjects, P = 0.862). There was an intensity-dependent increase in FVC during exercise in both groups; however, AA subjects presented lower FVC (interaction P < 0.001) at 8-, 12-, 16-, 20-, and 24-kg workloads (e.g., 24 kg: 324 ± 20 ml·min-1·100 mmHg-1 in CA subjects vs. 241 ± 21 ml·min-1·100 mmHg-1 in AA subjects, P < 0.001). FBF responses to exercise were also lower in AA subjects (interaction P < 0.001), whereas MAP responses did not differ between groups (e.g., ∆MAP at 24 kg: +19 ± 2 mmHg in CA subjects vs. +19 ± 2 mmHg in AA subjects, interaction P = 0.950). These findings indicate lower hyperemic responses to rhythmic handgrip exercise in AA men compared with CA men. NEW & NOTEWORTHY It is known that African-American individuals have heightened vasoconstriction and reduced vasodilation under resting conditions compared with Caucasian-American individuals. Here, we identified that the hyperemic response to moderate and high-intensity rhythmic handgrip exercise was lower in healthy young African-American men.
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Affiliation(s)
- Thales C Barbosa
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
| | - Jasdeep Kaur
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
| | - Brandi Y Stephens
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
| | - John D Akins
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
| | - David M Keller
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
| | - R Matthew Brothers
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
| | - Paul J Fadel
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington , Arlington, Texas
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Covassin N, Greene EL, Singh P, Somers VK. Disparities in Hypertension Among African-Americans: Implications of Insufficient Sleep. Curr Hypertens Rep 2018; 20:57. [PMID: 29884924 DOI: 10.1007/s11906-018-0855-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW Sleep deficiency has been proposed as a potential contributor to racial disparities in cardiovascular health. We present contemporary evidence on the unequal burden of insufficient sleep in Blacks/African-Americans and the repercussions for disparate risk of hypertension. RECENT FINDINGS The prevalence of insufficient sleep is high and rising and has been recognized as an important cardiovascular risk factor. Presumably due to a constellation of environmental, psychosocial, and individual determinants, these risks appear exacerbated in Blacks/African-Americans, who are more likely to experience short sleep than other ethnic/racial groups. Population-based data suggest that the risk of hypertension associated with sleep deficiency is greater in those of African ancestry. However, there is a paucity of experimental evidence linking short sleep duration to blood pressure levels in African-Americans. Blacks/African-Americans may be more vulnerable to sleep deficiency and to its hypertensive effects. Future research is needed to unequivocally establish causality and determine the mechanism underlying the postulated racial inequalities in sleep adequacy and consequent cardiovascular risk.
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Affiliation(s)
- Naima Covassin
- Department of Cardiovascular Medicine, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN, 55905, USA.
| | - Eddie L Greene
- Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Prachi Singh
- Department of Cardiovascular Medicine, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN, 55905, USA
| | - Virend K Somers
- Department of Cardiovascular Medicine, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN, 55905, USA
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Abstract
OBJECTIVE Racial discrimination is increasingly recognized as a contributor to increased cardiovascular disease (CVD) risk among African Americans. Previous research has shown significant overlap between racial discrimination and hostility, an established predictor of CVD risk including alterations in adrenergic receptor functioning. The present study examined the associations of racial discrimination and hostility with adrenergic receptor responsiveness. METHODS In a sample (N = 57) of young to middle-aged African American adults (51% female) with normal and mildly elevated blood pressure, a standardized isoproterenol sensitivity test (CD25) was used to evaluate β-AR responsiveness, whereas the dose of phenylephrine required to increase mean arterial pressure by 25 mm Hg (PD25) was used to assess α1-AR responsiveness. Racial discrimination was measured using the Perceived Racism Scale and hostility was assessed using the Cook-Medley Hostility Scale. RESULTS In hierarchical regression models, greater racial discrimination, but not hostility, emerged as a significant predictor of decreased β-adrenergic receptor responsiveness (β = .38, p = .004). However, moderation analysis revealed that the association between racial discrimination and blunted β-adrenergic receptor responsiveness was strongest among those with higher hostility (β = .49, 95% confidence interval = .17-.82, p = .004). In addition, hostility, but not racial discrimination, significantly predicted α1-AR responsiveness. CONCLUSIONS These findings suggest racial discrimination was associated with blunted β-adrenergic receptor responsiveness, providing further evidence of the potential contribution of racial discrimination to increased CVD risk among African Americans. The adverse effects of discrimination on cardiovascular health may be enhanced in individuals with higher levels of hostility.
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40
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Vranish JR, Holwerda SW, Young BE, Credeur DP, Patik JC, Barbosa TC, Keller DM, Fadel PJ. Exaggerated Vasoconstriction to Spontaneous Bursts of Muscle Sympathetic Nerve Activity in Healthy Young Black Men. Hypertension 2017; 71:192-198. [PMID: 29203629 DOI: 10.1161/hypertensionaha.117.10229] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 09/05/2017] [Accepted: 09/22/2017] [Indexed: 12/16/2022]
Abstract
Blacks have the highest prevalence of hypertension, putting them at greater risk of cardiovascular disease and death. Previous studies have reported that, relative to whites, healthy black men have augmented pressor responses to sympathoexcitatory stressors. Although important, these studies do not inform about the resting state and the influence of spontaneous changes in resting muscle sympathetic nerve activity (MSNA). Likewise, little is known about the transduction of MSNA into a vascular response at rest on a beat-to-beat basis. Accordingly, we tested the hypothesis that relative to whites, blacks would exhibit greater vasoconstriction and pressor responses following spontaneous bursts of MSNA. Mean arterial pressure, common femoral artery blood flow, and MSNA were continuously recorded during 20 minutes of supine rest in 35 young healthy men (17 blacks and 18 whites). Signal averaging was used to characterize changes in leg vascular conductance, total vascular conductance, and mean arterial pressure following spontaneous MSNA bursts. Blacks demonstrated significantly greater decreases in leg vascular conductance (blacks: -15.0±1.0%; whites: -11.5±1.2%; P=0.042) and total vascular conductance (blacks: -8.6±0.9%; whites: -5.1±0.4%; P=0.001) following MSNA bursts, which resulted in greater mean arterial pressure increases (blacks: +5.2±0.6 mm Hg; whites: +3.9±0.3 mm Hg; P=0.04). These exaggerated responses in blacks compared with whites were present whether MSNA bursts occurred in isolation (singles) or in combination (multiples) and were graded with increases in burst height. Collectively, these findings suggest that healthy young black men exhibit augmented sympathetic vascular transduction at rest and provide novel insight into potential mechanism(s) by which this population may develop hypertension later in life.
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Affiliation(s)
- Jennifer R Vranish
- From the Department of Kinesiology, University of Texas at Arlington (J.R.V., B.E.Y., J.C.P., T.C.B., D.M.K., P.J.F.); School of Kinesiology, University of Southern Mississippi, Hattiesburg (D.P.C.); and Department of Health and Human Physiology, University of Iowa, Iowa City (S.W.H.)
| | - Seth W Holwerda
- From the Department of Kinesiology, University of Texas at Arlington (J.R.V., B.E.Y., J.C.P., T.C.B., D.M.K., P.J.F.); School of Kinesiology, University of Southern Mississippi, Hattiesburg (D.P.C.); and Department of Health and Human Physiology, University of Iowa, Iowa City (S.W.H.)
| | - Benjamin E Young
- From the Department of Kinesiology, University of Texas at Arlington (J.R.V., B.E.Y., J.C.P., T.C.B., D.M.K., P.J.F.); School of Kinesiology, University of Southern Mississippi, Hattiesburg (D.P.C.); and Department of Health and Human Physiology, University of Iowa, Iowa City (S.W.H.)
| | - Daniel P Credeur
- From the Department of Kinesiology, University of Texas at Arlington (J.R.V., B.E.Y., J.C.P., T.C.B., D.M.K., P.J.F.); School of Kinesiology, University of Southern Mississippi, Hattiesburg (D.P.C.); and Department of Health and Human Physiology, University of Iowa, Iowa City (S.W.H.)
| | - Jordan C Patik
- From the Department of Kinesiology, University of Texas at Arlington (J.R.V., B.E.Y., J.C.P., T.C.B., D.M.K., P.J.F.); School of Kinesiology, University of Southern Mississippi, Hattiesburg (D.P.C.); and Department of Health and Human Physiology, University of Iowa, Iowa City (S.W.H.)
| | - Thales C Barbosa
- From the Department of Kinesiology, University of Texas at Arlington (J.R.V., B.E.Y., J.C.P., T.C.B., D.M.K., P.J.F.); School of Kinesiology, University of Southern Mississippi, Hattiesburg (D.P.C.); and Department of Health and Human Physiology, University of Iowa, Iowa City (S.W.H.)
| | - David M Keller
- From the Department of Kinesiology, University of Texas at Arlington (J.R.V., B.E.Y., J.C.P., T.C.B., D.M.K., P.J.F.); School of Kinesiology, University of Southern Mississippi, Hattiesburg (D.P.C.); and Department of Health and Human Physiology, University of Iowa, Iowa City (S.W.H.)
| | - Paul J Fadel
- From the Department of Kinesiology, University of Texas at Arlington (J.R.V., B.E.Y., J.C.P., T.C.B., D.M.K., P.J.F.); School of Kinesiology, University of Southern Mississippi, Hattiesburg (D.P.C.); and Department of Health and Human Physiology, University of Iowa, Iowa City (S.W.H.).
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Marinos A, Gamboa A, Celedonio JE, Preheim BA, Okamoto LE, Ramirez CE, Arnold AC, Diedrich A, Biaggioni I, Shibao CA. Hypertension in Obese Black Women is Not Caused by Increased Sympathetic Vascular Tone. J Am Heart Assoc 2017; 6:JAHA.117.006971. [PMID: 29151035 PMCID: PMC5721777 DOI: 10.1161/jaha.117.006971] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Background Black women have one of the highest prevalence rates of hypertension and obesity in the United States. We previously reported that sympathetic activation induced by obesity is a significant contributor to hypertension in white patients. It is unknown whether sympathetic activity similarly contributes to hypertension in obese black women. Methods and Results We studied 42 obese women (16 white, body mass index 36±4 kg/m2, 44% with hypertension; 26 black, body mass index 35±4 kg/m2, 46% with hypertension). Antihypertensive medications were discontinued for 2 weeks before the day of the study. All patients underwent complete autonomic blockade with trimethaphan at a dosage of 4 mg/min. Resting sympathetic activity determined from muscle sympathetic nerve recordings was similar between obese black women with hypertension and those with normotension. In whites, sympathetic activity was elevated in obese patients with hypertension compared with normotension; the decrease in mean arterial blood pressure produced by trimethaphan was greater in obese white patients with hypertension compared with those with normotension (−26.8±9.7 mm Hg versus −14.8±7.9 mm Hg, P=0.02). In contrast, there was no difference in the depressor responses induced by trimethaphan between obese black women with hypertension and those with normotension (−15.5±10.5 mm Hg versus −12.3±10.2 mm Hg, P=0.45). Mean arterial blood pressure remained elevated in obese blacks with hypertension compared with those with normotension during trimethaphan infusion (83.7±15.0 mm Hg versus 71.7±9.8 mm Hg, P=0.02). Heart rate increased similarly with trimethaphan between white (P=0.11) and black (P=0.76) women with hypertension and normotension. Conclusions These findings suggest that sympathetic activity does not contribute to hypertension in obese black women and provide further evidence for racial differences in hypertension mechanisms.
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42
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Adefurin A, Ghimire LV, Kohli U, Muszkat M, Sofowora GG, Li C, Levinson RT, Paranjape SY, Stein CM, Kurnik D. Genetic variation in the alpha 1B-adrenergic receptor and vascular response. THE PHARMACOGENOMICS JOURNAL 2017; 17:366-371. [PMID: 27089938 PMCID: PMC5071105 DOI: 10.1038/tpj.2016.29] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 02/04/2016] [Accepted: 02/26/2016] [Indexed: 12/26/2022]
Abstract
The alpha1B (α1B)-adrenergic receptors contribute to vasoconstriction in humans. We tested the hypothesis that variation in the ADRA1B gene contributes to interindividual variability and ethnic differences in adrenergic vasoconstriction. We measured dorsal hand vein responses to increasing doses of phenylephrine in 64 Caucasians and 41 African Americans and genotyped 34 ADRA1B variants. We validated findings in another model of catecholamine-induced vasoconstriction, the increase in mean arterial pressure (ΔMAP) during a cold pressor test (CPT). One ADRA1B variant, rs10070745, present in 14 African-American heterozygotes but not in Caucasians, was associated with a lower phenylephrine ED50 (geometric mean (95% confidence interval), 144 (69-299) ng ml-1) compared with 27 African-American non-carriers (208 (130-334) ng ml-1; P=0.015) and contributed to the ethnic differences in ED50. The same variant was also associated with a greater ΔMAP during CPT (P=0.008). In conclusion, ADRA1B rs10070745 was significantly associated with vasoconstrictor responses after adrenergic stimulation and contributed to the ethnic difference in phenylephrine sensitivity.
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Affiliation(s)
- Abiodun Adefurin
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Laxmi V. Ghimire
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Utkarsh Kohli
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Mordechai Muszkat
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Gbenga G. Sofowora
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Chun Li
- Department of Biostatistics, Center for Human Genetics Research, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Rebecca T. Levinson
- Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Sachin Y. Paranjape
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - C. Michael Stein
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Daniel Kurnik
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Clinical Pharmacology Unit, Rambam Medical Center, Haifa, Israel; Rappaport Faculty of Medicine, Technion – Israel Institute of Technology, Haifa, Israel
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Sherwood A, Hill LK, Blumenthal JA, Johnson KS, Hinderliter AL. Race and sex differences in cardiovascular α-adrenergic and β-adrenergic receptor responsiveness in men and women with high blood pressure. J Hypertens 2017; 35:975-981. [PMID: 28306633 PMCID: PMC5785915 DOI: 10.1097/hjh.0000000000001266] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Hypertension is associated with unfavorable changes in adrenergic receptor responsiveness, but the relationship of race and sex to adrenergic receptor responsiveness in the development of cardiovascular disease is unclear. This study examined α-adrenergic and ß-adrenergic receptor responsiveness in African-American and white men and women with untreated high blood pressure (BP) (HBP) and with normal BP. METHODS AND RESULTS The study sample comprised 161 African-American and white men and women in the age range 25-45 years. Isoproterenol, a nonselective ß-adrenergic receptor agonist, was administered intravenously to determine the bolus dose required to increase heart rate by 25 bpm, an index of β-adrenergic receptor responsiveness. Similarly, phenylephrine, an α1-adrenergic receptor agonist, was administered to determine the bolus dose required to increase BP by 25 mmHg, an index of vascular α1-adrenergic receptor responsiveness. HBP (P < 0.01), male sex (P = 0.04), and higher BMI (P < 0.01) were all associated with reduced β-adrenergic receptor responsiveness, with a similar trend observed for African-American race (P = 0.07). Conversely, α1-adrenergic receptor responsiveness was increased in association with HBP (P < 0.01), female sex (P < 0.01), and African-American race (P < 0.01). CONCLUSION In the early stages of hypertension, cardiovascular β-adrenergic receptors demonstrate blunted responsiveness, whereas conversely α1-adrenergic receptors exhibit increased responsiveness. This pattern of receptor changes is especially evident in men and African-Americans, is exacerbated by obesity, and may contribute to the development of cardiovascular disease.
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Affiliation(s)
- Andrew Sherwood
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, USA
| | - LaBarron K. Hill
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, USA
| | - James A. Blumenthal
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, USA
| | - Kristy S. Johnson
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, USA
| | - Alan L. Hinderliter
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Yan H, Ranadive SM, Lane-Cordova AD, Kappus RM, Behun MA, Cook MD, Woods JA, Wilund KR, Baynard T, Halliwill JR, Fernhall B. Effect of acute aerobic exercise and histamine receptor blockade on arterial stiffness in African Americans and Caucasians. J Appl Physiol (1985) 2017; 122:386-395. [PMID: 27979988 DOI: 10.1152/japplphysiol.01115.2015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 11/28/2016] [Accepted: 12/07/2016] [Indexed: 11/22/2022] Open
Abstract
African Americans (AA) exhibit exaggerated central blood pressure (BP) and arterial stiffness measured by pulse wave velocity (PWV) in response to an acute bout of maximal exercise compared with Caucasians (CA). However, whether potential racial differences exist in central BP, elastic, or muscular arterial distensibility after submaximal aerobic exercise remains unknown. Histamine receptor activation mediates sustained postexercise hyperemia in CA but the effect on arterial stiffness is unknown. This study sought to determine the effects of an acute bout of aerobic exercise on central BP and arterial stiffness and the role of histamine receptors, in AA and CA. Forty-nine (22 AA, 27 CA) young and healthy subjects completed the study. Subjects were randomly assigned to take either histamine receptor antagonist or control placebo. Central blood BP and arterial stiffness measurements were obtained at baseline, and at 30, 60, and 90 min after 45 min of moderate treadmill exercise. AA exhibited greater central diastolic BP, elevated brachial PWV, and local carotid arterial stiffness after an acute bout of submaximal exercise compared with CA, which may contribute to their higher risk of cardiovascular disease. Unexpectedly, histamine receptor blockade did not affect central BP or PWV in AA or CA after exercise, but it may play a role in mediating local carotid arterial stiffness. Furthermore, histamine may mediate postexercise carotid arterial dilation in CA but not in AA. These observations provide evidence that young and healthy AA exhibit an exaggerated hemodynamic response to exercise and attenuated vasodilator response compared with CA.NEW & NOTEWORTHY African Americans are at greater risk for developing cardiovascular disease than Caucasians. We are the first to show that young and healthy African Americans exhibit greater central blood pressure, elevated brachial stiffness, and local carotid arterial stiffness following an acute bout of submaximal exercise compared with Caucasians, which may contribute to their higher risk of cardiovascular disease. Furthermore, African Americans exhibit attenuated vasodilator response compared with Caucasians.
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Affiliation(s)
- Huimin Yan
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, Illinois; .,Department of Exercise and Health Sciences, University of Massachusetts Boston, Boston, Massachusetts
| | - Sushant M Ranadive
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, Illinois
| | - Abbi D Lane-Cordova
- Integrative Physiology Laboratory, Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois
| | - Rebecca M Kappus
- Department of Health and Exercise Science, Appalachian State University, Boone, North Carolina; and
| | - Michael A Behun
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, Illinois
| | - Marc D Cook
- Integrative Physiology Laboratory, Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois
| | - Jeffrey A Woods
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, Illinois
| | - Kenneth R Wilund
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, Illinois
| | - Tracy Baynard
- Integrative Physiology Laboratory, Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois
| | - John R Halliwill
- Department of Human Physiology, University of Oregon, Eugene, Oregon
| | - Bo Fernhall
- Integrative Physiology Laboratory, Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois
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Hill LK, Sherwood A, Blumenthal JA, Hinderliter AL. Hemodynamics and Vascular Hypertrophy in African Americans and Caucasians With High Blood Pressure. Am J Hypertens 2016; 29:1380-1385. [PMID: 27481880 DOI: 10.1093/ajh/hpw080] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 07/06/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Hypertension in African Americans is characterized by greater systemic vascular resistance (SVR) compared with Caucasian Americans, but the responsible mechanisms are not known. The present study sought to determine if peripheral vascular hypertrophy is a potential mechanism contributing to elevated SVR in African Americans with high blood pressure (BP). METHODS In a biracial sample of 80 men and women between the ages of 25 and 45 years, with clinic BP in the range 130/85-160/99mm Hg, we assessed cardiac output and SVR, in addition to BP. Minimum forearm vascular resistance (MFVR), a marker of vascular hypertrophy, also was assessed. RESULTS SVR was elevated in African Americans compared with Caucasians (P < 0.001). Regression models indicated that age, body mass index, 24-hour diastolic BP, and ethnicity were significant predictors of SVR. There was also a significant interaction between ethnicity and MFVR in explaining SVR in the study sample. In particular, there was a significant positive association between MFVR and SVR among African Americans (P = 0.002), whereas the association was inverse and not statistically significant among Caucasians (P = 0.601). CONCLUSION Hypertrophy of the systemic microvasculature may contribute to the elevated SVR that is characteristic of the early stages of hypertension in African American compared with Caucasians.
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Kim SK, Avila JJ, Massett MP. Strain survey and genetic analysis of vasoreactivity in mouse aorta. Physiol Genomics 2016; 48:861-873. [PMID: 27764765 DOI: 10.1152/physiolgenomics.00054.2016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 09/25/2016] [Indexed: 11/22/2022] Open
Abstract
Understanding the genetic influence on vascular reactivity is important for identifying genes underlying impaired vascular function. The purpose of this study was to characterize the genetic contribution to intrinsic vascular function and to identify loci associated with phenotypic variation in vascular reactivity in mice. Concentration response curves to phenylephrine (PE), potassium chloride (KCl), acetylcholine (ACh), and sodium nitroprusside (SNP) were generated in aortic rings from male mice (12 wk old) from 27 inbred mouse strains. Significant strain-dependent differences were found for both maximal responses and sensitivity for each agent, except for SNP Max (%). Strain differences for maximal responses to ACh, PE, and KCl varied by two- to fivefold. On the basis of these large strain differences, we performed genome-wide association mapping (GWAS) to identify loci associated with variation in responses to these agents. GWAS for responses to ACh identified four significant and 19 suggestive loci. Several suggestive loci for responses to SNP, PE, and KCl (including one significant locus for KCl EC50) were also identified. These results demonstrate that intrinsic endothelial function, and more generally vascular function, is genetically determined and associated with multiple genomic loci. Furthermore, these results are supported by the finding that several genes residing in significant and suggestive loci for responses to ACh were previously identified in rat and/or human quantitative trait loci/GWAS for cardiovascular disease. This study represents the first step toward the unbiased comprehensive discovery of genetic determinants that regulate intrinsic vascular function, particularly endothelial function.
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Affiliation(s)
- Seung Kyum Kim
- Department of Health and Kinesiology, Texas A&M University, College Station, Texas
| | - Joshua J Avila
- Department of Health and Kinesiology, Texas A&M University, College Station, Texas
| | - Michael P Massett
- Department of Health and Kinesiology, Texas A&M University, College Station, Texas
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Ranadive SM, Yan H, Lane AD, Kappus RM, Cook MD, Sun P, Harvey I, Ploutz-Synder R, Woods JA, Wilund KR, Fernhall BO. Aerobic Exercise Training and Arterial Changes in African Americans versus Caucasians. Med Sci Sports Exerc 2016. [PMID: 26225767 DOI: 10.1249/mss.0000000000000742] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
UNLABELLED African Americans (AA) have increased carotid artery intima-media thickness and decreased vascular function compared with their Caucasian (CA) peers. Aerobic exercise prevents and potentially reverses arterial dysfunction. PURPOSE The purpose of this study was to examine the effect of 8 wk of moderate- to high-intensity aerobic training in young healthy sedentary AA and CA men and women. METHODS Sixty-four healthy volunteers (men, 28; women, 36) with mean age 24 yr underwent measures of arterial structure, function, and blood pressure (BP) variables at baseline, after the 4-wk control period, and 8 wk after training. RESULTS There was a significant increase in VO2peak among both groups after exercise training. Brachial systolic BP decreased significantly after the control period in both groups but not after exercise training. Carotid pulse pressure decreased significantly in both groups after exercise training as compared with that in baseline. There was no change in any of the other BP variables. AA had higher intima-media thickness at baseline and after the control period but it significantly decreased after exercise training compared with that of CA. AA had significantly lower baseline forearm blood flow and reactive hyperemia compared with those of CA, but exercise training had no effect on these variables. There was no significant difference in arterial stiffness (central pulse wave velocity) and wave-reflection (augmentation index) between the two groups at any time point. CONCLUSIONS This is the first study to show that 8 wk of aerobic exercise training causes significant improvement in the arterial structure in young, healthy AA, making it comparable with the CA and with minimal effects on BP variables.
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Affiliation(s)
- Sushant M Ranadive
- 1Department of Anesthesiology, Mayo Clinic, Rochester, MN; 2Department of Kinesiology and Community Health, Urbana, IL; 3Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL; 4Department of Health and Kinesiology Transdisciplinary Center on Health Equity Research, Texas A&M University, College Station, TX; and 5Division of Space Life Sciences, Universities Space Research Association, Houston, TX
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Differential Post-Exercise Blood Pressure Responses between Blacks and Caucasians. PLoS One 2016; 11:e0153445. [PMID: 27074034 PMCID: PMC4830622 DOI: 10.1371/journal.pone.0153445] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/29/2016] [Indexed: 11/19/2022] Open
Abstract
Post-exercise hypotension (PEH) is widely observed in Caucasians (CA) and is associated with histamine receptors 1- and 2- (H1R and H2R) mediated post-exercise vasodilation. However, it appears that blacks (BL) may not exhibit PEH following aerobic exercise. Hence, this study sought to determine the extent to which BL develop PEH, and the contribution of histamine receptors to PEH (or lack thereof) in this population. Forty-nine (22 BL, 27 CA) young and healthy subjects completed the study. Subjects were randomly assigned to take either a combined H1R and H2R antagonist (fexofenadine and ranitidine) or a control placebo. Supine blood pressure (BP), cardiac output and peripheral vascular resistance measurements were obtained at baseline, as well as at 30 min, 60 min and 90 min after 45 min of treadmill exercise at 70% heart rate reserve. Exercise increased diastolic BP in young BL but not in CA. Post-exercise diastolic BP was also elevated in BL after exercise with histamine receptor blockade. Moreover, H1R and H2R blockade elicited differential responses in stroke volume between BL and CA at rest, and the difference remained following exercise. Our findings show differential BP responses following exercise in BL and CA, and a potential role of histamine receptors in mediating basal and post-exercise stroke volume in BL. The heightened BP and vascular responses to exercise stimulus is consistent with the greater CVD risk in BL.
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Okada Y, Jarvis SS, Best SA, Edwards JG, Hendrix JM, Adams-Huet B, Vongpatanasin W, Levine BD, Fu Q. Sympathetic Neural and Hemodynamic Responses During Cold Pressor Test in Elderly Blacks and Whites. Hypertension 2016; 67:951-8. [PMID: 27021009 DOI: 10.1161/hypertensionaha.115.06700] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Accepted: 03/01/2016] [Indexed: 11/16/2022]
Abstract
The sympathetic response during the cold pressor test (CPT) has been reported to be greater in young blacks than whites, especially in those with a family history of hypertension. Because blood pressure (BP) increases with age, we evaluated whether elderly blacks have greater sympathetic activation during CPT than age-matched whites. BP, heart rate, cardiac output, and muscle sympathetic nerve activity were measured during supine baseline, 2-minute CPT, and 3-minute recovery in 47 elderly (68 ± 7 [SD] years) volunteers (12 blacks and 35 whites). Baseline BP, heart rate, cardiac output, or muscle sympathetic nerve activity did not differ between races. Systolic and diastolic BP and heart rate increased during CPT (all P<0.001) with no racial differences (all P > 0.05). Cardiac output increased during CPT and ≤ 30 s of recovery in both groups, but was lower in blacks than whites. Muscle sympathetic nerve activity increased during CPT in both groups (both P<0.001); the increase in burst frequency was similar between groups, whereas the increase in total activity was smaller in blacks (P=0.030 for interaction). Peak change (Δ) in diastolic BP was correlated with Δ total activity at 1 minute into CPT in both blacks (r=0.78,P=0.003) and whites (r=0.43,P=0.009), whereas the slope was significantly greater in blacks (P=0.007). Thus, elderly blacks have smaller sympathetic and central hemodynamic (eg, cardiac output) responses, but a greater pressor response for a given sympathetic activation during CPT than elderly whites. This response may stem from augmented sympathetic vascular transduction, greater sympathetic activation to other vascular bed(s), or enhanced nonadrenergically mediated vasoconstriction in elderly blacks.
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Affiliation(s)
- Yoshiyuki Okada
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.)
| | - Sara S Jarvis
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.)
| | - Stuart A Best
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.)
| | - Jeffrey G Edwards
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.)
| | - Joseph M Hendrix
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.)
| | - Beverley Adams-Huet
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.)
| | - Wanpen Vongpatanasin
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.)
| | - Benjamin D Levine
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.)
| | - Qi Fu
- From the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas (Y.O., S.S.J., S.A.B., J.G.E., B.D.L., Q.F.); Departments of Internal Medicine (Y.O., S.S.J., S.A.B., B.A.-H., W.V., B.D.L., Q.F.) and Anesthesiology and Pain (J.M.H.), UT Southwestern Medical Center, Dallas, TX; Department of Special Care Dentistry, Matsumoto Dental University, Nagano, Japan (Y.O.); and Department of Biological Sciences, Northern Arizona University, Flagstaff (S.S.J.).
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Carter SJ, Goldsby TU, Fisher G, Plaisance EP, Gower BA, Glasser SP, Hunter GR. Systolic blood pressure response after high-intensity interval exercise is independently related to decreased small arterial elasticity in normotensive African American women. Appl Physiol Nutr Metab 2016; 41:484-90. [PMID: 26953821 DOI: 10.1139/apnm-2015-0512] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Aerobic exercise transiently lowers blood pressure. However, limited research has concurrently evaluated blood pressure and small arterial elasticity (SAE), an index of endothelial function, among African American (AA) and European American (EA) women the morning after (i.e., ≈22 h later) acute bouts of moderate-intensity continuous (MIC) and high-intensity interval (HII) exercise matched for total work. Because of greater gradients of shear stress, it was hypothesized that HII exercise would elicit a greater reduction in systolic blood pressure (SBP) compared to MIC exercise. After baseline, 22 AA and EA women initiated aerobic exercise training 3 times/week. Beginning at week 8, three follow-up assessments were conducted over the next 8 weeks at random to measure resting blood pressure and SAE. In total all participants completed 16 weeks of training. Follow-up evaluations were made: (i) in the trained state (TS; 8-16 weeks of aerobic training); (ii) ≈22 h after an acute bout of MIC exercise; and (iii) ≈22 h after an acute bout of HII exercise. Among AAs, the acute bout of HII exercise incited a significant increase in SBP (mm Hg) (TS, 121 ± 14 versus HII, 128 ± 14; p = 0.01) whereas responses (TS, 116 ± 12 versus HII, 113 ± 9; p = 0.34) did not differ in EAs. After adjusting for race, changes in SAE were associated (partial r = -0.533; p = 0.01) with changes in SBP following HII exercise. These data demonstrate an acute, unaccustomed bout of HII exercise produces physiological perturbations resulting in a significant increase in SBP that are independently associated with decreased SAE among AA women, but not EA women.
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Affiliation(s)
- Stephen J Carter
- a Department of Human Studies, University of Alabama at Birmingham, Birmingham, AL 35233, USA.,c Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - TaShauna U Goldsby
- c Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL 35233, USA.,d Office of Energetics, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Gordon Fisher
- a Department of Human Studies, University of Alabama at Birmingham, Birmingham, AL 35233, USA.,b Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Eric P Plaisance
- a Department of Human Studies, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Barbara A Gower
- b Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Stephen P Glasser
- e Department of Preventive Medicine, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Gary R Hunter
- a Department of Human Studies, University of Alabama at Birmingham, Birmingham, AL 35233, USA.,b Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35233, USA
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