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Nowicki A, Gambin B, Secomski W, Trawinski Z, Szubielski M, Olszewski R. DOES FLOW-MEDIATED DILATION NORMALIZATION FOR BASE-SCALED SHEAR RATE IMPROVE ITS VALUE IN CORONARY ARTERY DISEASE DIAGNOSTICS? ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:2551-2555. [PMID: 32600670 DOI: 10.1016/j.ultrasmedbio.2020.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 05/28/2020] [Accepted: 05/29/2020] [Indexed: 06/11/2023]
Abstract
The article presents a new normalization of flow-mediated dilation (FMD) in the radial artery, taking into account the parameter BSSR being equal to the ratio of the basal shear rate (BS) measured before the cuff inflation and post occlusive shear rate (SR). The in vivo usefulness of the new normalization algorithm was evaluated in two groups of patients. In group I, comprising 15 healthy volunteers, the normalized FMD/SR was (3.19 ± 1.4)•10-4, while in group II, comprising 13 patients with stable coronary artery disease (CAD), it was (1.02 ± 0.76)•10-4. We calculated almost 50% larger difference between the average values after normalizing FMD/BSSR. Specifically, the FMD/BSSR was equal to 28 ± 9.40 in group I and 6.01 ± 3.74 in group II. The prediction of CAD patients based on FMD/SR values had a sensitivity of 83.3% and a specificity of 84.6%, whereas the prediction of CAD patients based on the FMD/BSSR values revealed 100% sensitivity and specificity. These results confirm the usefulness of the novel normalization algorithm of the FMD in differentiation of normal patients from those with stable CAD.
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Affiliation(s)
- Andrzej Nowicki
- Department of Ultrasound, Institute of the Fundamental Technological Research of the Polish Academy of Sciences, Warsaw, Poland.
| | - Barbara Gambin
- Department of Ultrasound, Institute of the Fundamental Technological Research of the Polish Academy of Sciences, Warsaw, Poland
| | - Wojciech Secomski
- Department of Ultrasound, Institute of the Fundamental Technological Research of the Polish Academy of Sciences, Warsaw, Poland
| | - Zbigniew Trawinski
- Department of Ultrasound, Institute of the Fundamental Technological Research of the Polish Academy of Sciences, Warsaw, Poland
| | | | - Robert Olszewski
- Department of Ultrasound, Institute of the Fundamental Technological Research of the Polish Academy of Sciences, Warsaw, Poland; Department of Geriatrics, National Institute of Geriatrics, Rheumatology and Rehabilitation, Warsaw, Poland
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El-Nahas NG, Badawy MM. Isometric Versus Aerobic Training Effects on Vascular Adaptation in Patients with Type 2 Diabetes. Pak J Biol Sci 2020; 22:400-405. [PMID: 31930828 DOI: 10.3923/pjbs.2019.400.405] [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] [Indexed: 11/15/2022]
Abstract
BACKGROUND AND OBJECTIVE Diabetes is known to be associated with arterial remodeling and dysfunction which predispose to different microvascular complications. This study was aimed to find out the effect of isometric versus aerobic training on vascular adaptation in patients with type 2 diabetes. MATERIALS AND METHODS The study was carried out on 40 type 2 diabetic patients (20 men and 20 women). Patients were selected from the outpatient clinic of El-Agouza Police Authority Hospital. They were assigned into 2 matched and equal groups in number. Group A with mean age of 49.55 years, received unilateral isometric handgrip exercise 22 min per session, 3 sessions per week for 8 weeks and group B with mean age 50.15 years, received aerobic exercise in form of arm ergometry for 30 min, 3 sessions per week for 8 weeks. They were assessed by a Doppler ultrasound for brachial artery adaptation (the brachial artery diameter, blood velocity and shear rate) before and after 8 weeks of training. RESULTS Group A showed significant improvement in brachial artery adaptation as increased brachial artery diameter from 4.28±0.19 to 4.43±0.18, baseline vessel velocity from 7.09±0.41 to 8.62±0.46 and its shear rate from 66.24±4.19 to 77.65±5.27, while in group B who received the aerobic exercise the results showed a minimal change between pre training and post-training results 4.24±0.23 to 4.26±0.21 for brachial artery diameter, 7.26±0.54 to 7.46±0.67 for blood velocity and 67.8±3.16 to 68.81±4.29 for shear rate respectively. CONCLUSION Isometric handgrip exercise improved brachial artery diameter, blood velocity and shear rate in patients with type 2 diabetes.
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Ghardashi-Afousi A, Davoodi M, Hesamabadi BK, Asvadi-Fard M, Bigi MAB, Izadi MR, Gaeini AA. Improved carotid intima-media thickness-induced high-intensity interval training associated with decreased serum levels of Dkk-1 and sclerostin in type 2 diabetes. J Diabetes Complications 2020; 34:107469. [PMID: 31706805 DOI: 10.1016/j.jdiacomp.2019.107469] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 09/18/2019] [Accepted: 10/07/2019] [Indexed: 12/23/2022]
Abstract
AIMS Carotid intima-media thickness (cIMT) is a validated surrogate marker of atherosclerosis. Dickkopf-1 (Dkk-1) and sclerostin modulate wingless signaling, which is involved in atherosclerosis. The purpose of this study was to investigate whether 12 weeks of high-intensity interval training (HIIT) would improve cIMT and serum Dkk-1 and sclerostin levels in patients with type 2 diabetes. METHODS Seventy-four sedentary patients with type 2 diabetes were randomly divided into HIIT and control groups. The HIIT group intervention was 6 intervals (4 min) at 85%-90% HRmax separated by 3 min at 45%-50% HRmax in 3 sessions/week for 12 weeks. Before and after the intervention, cIMT, artery diameter and wall/lm ratio were recorded with high-resolution ultrasound. Serum sclerostin and Dkk-1 were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS cIMT decreased significantly in the HIIT group (0.83 ± 0.17 baseline, 0.71 ± 0.14 follow-up) compared to the control group (0.84 ± 0.20 baseline, 0.85 ± 0.19 follow-up) (P < .05). Dkk-1 and sclerostin decreased significantly after 12 weeks of HIIT (P < .01). In addition, VO2peak was increased in the HIIT group than the control group (by 6.2 mL/kg/min) (P < .05). There was a positive correlation between percent changes in cIMT and percent changes in Dkk-1 and sclerostin (both P < .01). Additionally, there were a negative correlation between percent changes VO2peak and cIMT (r = - 0.740, P = .003), Dkk-1 (r = - 0.844, P < .001) and sclerostin (r = - 0.575, P = .001) in HIIT group. CONCLUSION Our results indicate that HIIT decreases cIMT, serum levels of Dkk-1 and sclerostin and improves VO2peak in patients with type 2 diabetes.
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Affiliation(s)
- Alireza Ghardashi-Afousi
- Department of Exercise Physiology, Faculty of Physical Education and Exercise Sciences, University of Tehran, Tehran, IR, Iran.
| | | | | | - Maryam Asvadi-Fard
- Department of Medicine, Iran University of Medical Science, Tehran, IR, Iran
| | | | - Mohammad Reza Izadi
- Department of Exercise Physiology, Faculty of Physical Education and Exercise Sciences, University of Shahid Chamran, Ahvaz, IR, Iran
| | - Abbas Ali Gaeini
- Department of Exercise Physiology, Faculty of Physical Education and Exercise Sciences, University of Tehran, Tehran, IR, Iran.
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Soares RN, Somani YB, Al-Qahtani AM, Proctor DN, Murias JM. Near-infrared spectroscopy detects transient decrements and recovery of microvascular responsiveness following prolonged forearm ischemia. Microvasc Res 2019; 125:103879. [DOI: 10.1016/j.mvr.2019.04.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 03/01/2019] [Accepted: 04/29/2019] [Indexed: 10/26/2022]
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Walker MA, Bailey TG, McIlvenna L, Allen JD, Green DJ, Askew CD. Acute Dietary Nitrate Supplementation Improves Flow Mediated Dilatation of the Superficial Femoral Artery in Healthy Older Males. Nutrients 2019; 11:E954. [PMID: 31035478 PMCID: PMC6566150 DOI: 10.3390/nu11050954] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 04/18/2019] [Accepted: 04/24/2019] [Indexed: 12/15/2022] Open
Abstract
Aging is often associated with reduced leg blood flow, increased arterial stiffness, and endothelial dysfunction, all of which are related to declining nitric oxide (NO) bioavailability. Flow mediated dilatation (FMD) and passive leg movement (PLM) hyperaemia are two techniques used to measure NO-dependent vascular function. We hypothesised that acute dietary nitrate (NO3-) supplementation would improve NO bioavailability, leg FMD, and PLM hyperaemia. Fifteen healthy older men (69 ± 4 years) attended two experiment sessions and consumed either 140 mL of concentrated beetroot juice (800 mg NO3-) or placebo (NO3--depleted beetroot juice) in a randomised, double blind, cross-over design study. Plasma nitrite (NO2-) and NO3-, blood pressure (BP), augmentation index (AIx75), pulse wave velocity (PWV), FMD of the superficial femoral artery, and PLM hyperaemia were measured immediately before and 2.5 h after consuming NO3- and placebo. Placebo had no effect but NO3- led to an 8.6-fold increase in plasma NO2-, which was accompanied by an increase in FMD (NO3-: +1.18 ± 0.94% vs. placebo: 0.23 ± 1.13%, p = 0.002), and a reduction in AIx75 (NO3-: -8.7 ± 11.6% vs. placebo: -4.6 ± 5.5%, p = 0.027). PLM hyperaemia, BP, and PWV were unchanged during both trials. This study showed that a dose of dietary NO3- improved NO bioavailability and enhanced endothelial function as measured by femoral artery FMD. These findings provide insight into the specific central and peripheral vascular responses to dietary NO3- supplementation in older adults.
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Affiliation(s)
- Meegan A Walker
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia.
| | - Tom G Bailey
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia.
- School of Human Movement and Nutrition Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
| | - Luke McIlvenna
- Institute for Health and Sport, College of Sport and Exercise Science, Victoria University, Melbourne, VIC 3031, Australia.
| | - Jason D Allen
- Institute for Health and Sport, College of Sport and Exercise Science, Victoria University, Melbourne, VIC 3031, Australia.
- Department of Kinesiology, University of Virginia, Charlottesville, VA 22903, USA.
| | - Daniel J Green
- School of Sport Sciences, Exercise and Health, University of Western Australia, West Perth, WA 6872, Australia.
| | - Christopher D Askew
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia.
- Sunshine Coast Health Institute, Sunshine Coast Hospital and Health Service, Birtinya, QLD 4575, Australia.
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Morales‐Acuna F, Ochoa L, Valencia C, Gurovich AN. Characterization of blood flow patterns and endothelial shear stress during flow‐mediated dilation. Clin Physiol Funct Imaging 2019; 39:240-245. [DOI: 10.1111/cpf.12564] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/13/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Francisco Morales‐Acuna
- Department of Rehabilitation Sciences College of Health Sciences The University of Texas at El PasoEl Paso TX USA
| | - Luis Ochoa
- Department of Mechanical Engineering W.M. Keck Center for 3D Innovation The University of Texas at El Paso El Paso TX USA
| | - Carolina Valencia
- Department of Rehabilitation Sciences College of Health Sciences The University of Texas at El PasoEl Paso TX USA
| | - Alvaro N. Gurovich
- Department of Rehabilitation Sciences College of Health Sciences The University of Texas at El PasoEl Paso TX USA
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Senefeld JW, Limberg JK, Lukaszewicz KM, Hunter SK. Exercise-induced hyperemia is associated with knee extensor fatigability in adults with type 2 diabetes. J Appl Physiol (1985) 2019; 126:658-667. [PMID: 30605399 DOI: 10.1152/japplphysiol.00854.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to compare fatigability, contractile function, and blood flow to the knee extensor muscles after dynamic exercise in patients with type 2 diabetes mellitus (T2DM) and controls. The hypotheses were that patients with T2DM would demonstrate greater fatigability than controls, and greater fatigability would be associated with a lower exercise-induced increase in blood flow and greater impairments in contractile function. Patients with T2DM ( n = 15; 8 men; 62.4 ± 9.0 yr; 30.4 ± 7.7 kg/m2; 7,144 ± 3,294 steps/day) and 15 healthy control subjects (8 men, 58.4 ± 6.9 yr; 28.4 ± 4.6 kg/m2; 7,893 ± 2,323 steps/day) were matched for age, sex, body mass index, and physical activity. Fatigability was quantified as the reduction in knee extensor power during a 6-min dynamic exercise. Before and after exercise, vascular ultrasonography and electrical stimulation were used to assess skeletal muscle blood flow and contractile properties, respectively. Patients with T2DM had greater fatigability (30.0 ± 20.1% vs. 14.6 ± 19.0%, P < 0.001) and lower exercise-induced hyperemia (177 ± 90% vs. 194 ± 79%, P = 0.04) than controls but similar reductions in the electrically evoked twitch amplitude (37.6 ± 24.8% vs. 31.6 ± 30.1%, P = 0.98). Greater fatigability of the knee extensor muscles was associated with postexercise reductions in twitch amplitude ( r = 0.64, P = 0.001) and lesser exercise-induced hyperemia ( r = -0.56, P = 0.009). Patients with T2DM had greater lower-limb fatigability during dynamic exercise, which was associated with reduced contractile function and lower skeletal muscle blood flow. Thus, treatments focused on enhancing perfusion and reversing impairments in contractile function in patients with T2DM may offset lower-limb fatigability and aid in increasing exercise capacity. NEW & NOTEWORTHY Although prior studies compare patients with type 2 diabetes mellitus (T2DM) with lean controls, our study includes controls matched for age, body mass, and physical activity to more closely assess the effects of T2DM. Patients with T2DM demonstrated no impairment in macrovascular endothelial function, evidenced by similar flow-mediated dilation to controls. However, patients with T2DM had greater fatigability and reduced exercise-induced increase in blood flow (hyperemia) after a lower-limb dynamic fatiguing exercise compared with controls.
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Affiliation(s)
- Jonathon W Senefeld
- Clinical and Translational Rehabilitation Health Sciences Program, Marquette University , Milwaukee, Wisconsin.,Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin
| | - Jacqueline K Limberg
- Department of Nutrition and Exercise Physiology, University of Missouri , Columbia, Missouri
| | - Kathleen M Lukaszewicz
- Clinical and Translational Rehabilitation Health Sciences Program, Marquette University , Milwaukee, Wisconsin.,Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin
| | - Sandra K Hunter
- Clinical and Translational Rehabilitation Health Sciences Program, Marquette University , Milwaukee, Wisconsin.,Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin
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Ghardashi Afousi A, Izadi MR, Rakhshan K, Mafi F, Biglari S, Gandomkar Bagheri H. Improved brachial artery shear patterns and increased flow-mediated dilatation after low-volume high-intensity interval training in type 2 diabetes. Exp Physiol 2018; 103:1264-1276. [DOI: 10.1113/ep087005] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 06/19/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Alireza Ghardashi Afousi
- Department of Exercise Physiology, Faculty of Physical Education and Exercise Sciences; University of Tehran; Tehran IR Iran
| | - Mohammad Reza Izadi
- Department of Exercise Physiology, Faculty of Physical Education and Exercise Sciences; University of Shahid Chamran; Ahvaz IR Iran
| | - Kamran Rakhshan
- Department of Medical Physiology, Faculty of Medicine; Iran University of Medical Sciences; Tehran IR Iran
| | - Farnoosh Mafi
- Department of Exercise Physiology, Faculty of Physical Education and Exercise Sciences; University of Tehran; Tehran IR Iran
| | - Soheil Biglari
- Department of Exercise Physiology, Faculty of Physical Education and Exercise Sciences; University of Tehran; Tehran IR Iran
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Soares RN, Reimer RA, Alenezi Z, Doyle-Baker PK, Murias JM. Near-infrared spectroscopy can detect differences in vascular responsiveness to a hyperglycaemic challenge in individuals with obesity compared to normal-weight individuals. Diab Vasc Dis Res 2018; 15:55-63. [PMID: 28931323 DOI: 10.1177/1479164117731481] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
OBJECTIVE To examine whether the near-infrared spectroscopy combined with vascular occlusion test technique could detect differences in vascular responsiveness during hyperglycaemia between normal-weight individuals and individuals with obesity. METHODS A total of 16 normal-weight individuals (body mass index, 21.3 ± 1.7 kg/m2) and 13 individuals with obesity (body mass index, 34.4 ± 2.0 kg/m2) were submitted to five vascular occlusion tests (Pre, 30, 60, 90 and 120 min after glucose challenge). Vascular responsiveness was determined by the Slope 2 (Slope 2 StO2) and the area under the curve (StO2AUC) of oxygen saturation derived from near-infrared spectroscopy-vascular occlusion test. RESULTS The Slope 2 StO2 increased from 1.07 ± 0.16%/s (Pre) to 1.53 ± 0.21%/s at 90 min ( p < 0.05) in the control group, while in obese it increased from 0.71 ± 0.09%/s (Pre) to 0.92 ± 0.14%/s at 60 min ( p < 0.05), and to 0.97 ± 0.10%/s ( p < 0.01) at 120 min after glucose ingestion. The StO2AUC decreased from 1729 ± 214% . sec (Pre) to 1259 ± 232% . sec at 60 min ( p < 0.05) and to 1034 ± 172% . sec at 90 min ( p < 0.05) in the normal-weight group, whereas it decreased at 90 min (637 ± 98% . sec; p < 0.05) and at 120 min (590 ± 93% . sec; p < 0.01) compared to 30 min (1232 ± 197% . sec) after glucose ingestion in individuals with obesity. CONCLUSION Near-infrared spectroscopy-vascular occlusion test technique was capable of detecting differences in vascular responsiveness during hyperglycaemia between normal-weight individuals and individuals with obesity.
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Affiliation(s)
| | - Raylene A Reimer
- 1 Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- 2 Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Zaid Alenezi
- 1 Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Patricia K Doyle-Baker
- 1 Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- 3 Faculty of Environmental Design, University of Calgary, Calgary, AB, Canada
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Soares RN, Reimer RA, Murias JM. Changes in vascular responsiveness during a hyperglycemia challenge measured by near-infrared spectroscopy vascular occlusion test. Microvasc Res 2017; 111:67-71. [DOI: 10.1016/j.mvr.2017.01.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/12/2017] [Accepted: 01/12/2017] [Indexed: 02/07/2023]
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Flow-mediated dilation: can new approaches provide greater mechanistic insight into vascular dysfunction in preeclampsia and other diseases? Curr Hypertens Rep 2015; 16:487. [PMID: 25182159 DOI: 10.1007/s11906-014-0487-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Endothelial dysfunction is a key feature of preeclampsia and may contribute to increased cardiovascular disease risk years after pregnancy. Flow-mediated dilation (FMD) is a non-invasive endothelial function test that predicts cardiovascular event risk. New protocols allow researchers to measure three components of the FMD response: FMD, low flow-mediated constriction, and shear stimulus. This review encourages researchers to think beyond "low FMD" by examining how these three components may provide additional insights into the mechanisms and location of vascular dysfunction. The review then examines what FMD studies reveal about vascular dysfunction in preeclampsia while highlighting opportunities to gain greater mechanistic insight from new protocols. Studies using traditional protocols show that FMD is low in mid-pregnancy prior to preeclampsia, at diagnosis, and for 3 years post-partum. However, FMD returns to normal by 10 years post-partum. Studies using new protocols are needed to gain more mechanistic insight.
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Irace C, Tripolino C, Scavelli F, Messiniti V, Tassone B, Della Valle E, Carallo C, Gnasso A. Blood viscosity but not shear stress associates with delayed flow-mediated dilation. Eur J Appl Physiol 2014; 115:747-53. [PMID: 25428725 DOI: 10.1007/s00421-014-3058-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 11/17/2014] [Indexed: 01/22/2023]
Abstract
PURPOSE Flow-mediated dilation (FMD) is a complex mechanism involving several mediators, and different hemodynamic forces. Temporally distinct FMD patterns can be elicited by ischemic stimulus. Some subjects dilate early after cuff release, while others dilate later or do not dilate at all. Aim of the present research was to verify if hemorheological and hemodynamic factors might influence different FMD pattern. METHODS 148 free-living subjects were studied. FMD was measured at 50 s, 2 min and 3 min. Blood viscosity was measured and shear stress calculated. Shear stress stimulus was quantified as the area under the curve after ischemia (SSAUC) over the first 40-s post-occlusion. RESULTS Based on the timing or absence of arterial dilation, 82 subjects were classified as Early dilators, 37 as Late dilators and 29 as No dilators. Peak FMD was 7.9 ± 4.3 % in Early dilators, and 9.1 ± 5.7 in Late dilators (p = NS). SSAUC was not significantly different among three groups, while blood viscosity was significantly higher in Late FMD subjects. Regression analyses showed the independent predictive role of age and blood viscosity on FMD patterns, and the lack of any association between FMD pattern and the magnitude of SS. CONCLUSIONS The present study demonstrates that age and blood viscosity but not the magnitude of SS explain the different timing of the dilatory response to ischemia.
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Affiliation(s)
- Concetta Irace
- Department of Clinical and Experimental Medicine, Magna Græcia University, University Campus "Salvatore Venuta", Viale Europa, Località Germaneto, 88100, Catanzaro, Italy
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Veglia F, Amato M, Giovannardi M, Ravani A, Tedesco CC, Frigerio B, Sansaro D, Tremoli E, Baldassarre D. Potentially spurious correlations between arterial size, flow-mediated dilation, and shear rate. Hypertension 2014; 64:1328-33. [PMID: 25245392 DOI: 10.1161/hypertensionaha.114.03608] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The use of indices formed from the ratio of 2 variables often generates spurious correlations with other variables that are mathematically coupled. In this context, we examined the correlations between percent flow-mediated dilation, baseline diameter, and shear rate. In a sample of 315 participants, with and without substantial vascular risk factors, the observed correlation coefficients between the variables were of a similar magnitude to those reported in the literature. We then applied a Monte Carlo procedure based on random permutations to remove any physical or physiological explanation for these correlations. We found that the median residual correlation coefficients were comparable with those observed in our original sample. When the confounding influence of artery size was adjusted for, the mean difference in percent flow-mediated dilation between high-risk and low-risk samples was halved. These findings indicate that the widely reported correlations between flow-mediated dilation, basal artery diameter, and shear rate have a substantial spurious component. This is because percent flow-mediated dilation and shear rate are mathematically coupled to artery size.
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Affiliation(s)
- Fabrizio Veglia
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.).
| | - Mauro Amato
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Marta Giovannardi
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Alessio Ravani
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Calogero C Tedesco
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Beatrice Frigerio
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Daniela Sansaro
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Elena Tremoli
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Damiano Baldassarre
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
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Irace C, Carallo C, Loprete A, Tripolino C, Scavelli F, Gnasso A. Delayed flow-mediated vasodilation and carotid atherosclerosis. Eur J Clin Invest 2013; 43:49-55. [PMID: 23145798 DOI: 10.1111/eci.12016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND In a previous study, we identified temporally distinct postischaemic flow-mediated dilation (FMD) patterns comparing the standard clinical measurement time of 50s postcuff release with measurement at 2 min. The comparison revealed a cohort with the highest FMD at 50s (Early FMD), another cohort with the highest FMD at 2 min (Late FMD) and a third cohort with no FMD (Absent FMD). The aim of this study was to examine whether these temporally distinct FMD patterns associated with different degrees of carotid atherosclerosis. MATERIALS AND METHODS One hundred and twenty-four free-living white subjects, participating in a cardio-vascular disease prevention campaign, were enrolled. FMD was measured at 50s, 2 min and 3 min after forearm ischaemia. The intima-media thickness (IMT) of the common carotid artery was measured, and the artery was evaluated for the presence and number of carotid plaques. RESULTS Fifty-seven subjects had Early FMD, 34 had Late FMD and 33 had Absent FMD. The three groups were comparable for age, sex and cardiovascular risk factors. The number of plaques in the carotid arteries, and IMT, increased progressively from Early, to Late, and to Absent FMD (P < 0·03), indicating that the FMD pattern is an independent predictive variable for IMT and carotid atherosclerosis. CONCLUSIONS The present study demonstrates that temporal patterns associated with the degree of atherosclerosis of the carotid arteries. Patients with delayed vasodilation (Late FMD) had a higher degree of atherosclerosis than those with early vasodilation (Early FMD), and subjects with no postischaemic vasodilation (Absent FMD) had the most atherosclerosis.
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Affiliation(s)
- Concetta Irace
- Dipartimento di Medicina Sperimentale e Clinica G. Salvatore, Magna Graecia University, Catanzaro, Italy.
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Barone Gibbs B, Dobrosielski DA, Bonekamp S, Stewart KJ, Clark JM. A randomized trial of exercise for blood pressure reduction in type 2 diabetes: effect on flow-mediated dilation and circulating biomarkers of endothelial function. Atherosclerosis 2012; 224:446-53. [PMID: 22889573 PMCID: PMC3459298 DOI: 10.1016/j.atherosclerosis.2012.07.035] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 07/23/2012] [Accepted: 07/25/2012] [Indexed: 01/22/2023]
Abstract
OBJECTIVE To investigate the effect of an exercise intervention on flow-mediated dilation (FMD) and circulating endothelial biomarkers in adults with type 2 diabetes (T2DM). METHODS Sedentary adults (n = 140), aged 40-65, with T2DM and untreated pre or Stage I hypertension or treated hypertension were randomized to a 6-month, supervised, exercise program (3× week) or a sedentary control. Assessments included BMI, body and visceral fat, blood pressure, lipids, HbA1c, insulin sensitivity (QUICKI), fitness, FMD, E-selectin, P-selectin, intracellular and vascular cellular adhesion molecules (ICAM, VCAM), and tissue plasminogen activator (tPA). Intervention effects were compared by t-tests. Pearson's correlations were calculated between changes in cardiovascular risk factors and endothelial outcomes. RESULTS Exercisers significantly improved BMI (-0.6 kg/m(2)), body fat % (-1.4%), HbA1c (-0.5%), and fitness (2.9 mL/kg min) vs. controls (p < 0.05). However, there were no differences between groups in changes in FMD, E-selectin, P-selectin, ICAM, VCAM, or tPA. Among exercisers, changes in cardiovascular risk factors correlated with several biomarkers. Decreased P-selectin correlated with decreased BMI (r = 0.29, p = 0.04) and increased HDL cholesterol (r = -0.36, p = 0.01). Decreased ICAM correlated with decreased triglycerides and HbA1c (r = 0.30, p = 0.04; r = 0.31, p = 0.03) and increased QUICKI (r = - 0.28, p = 0.05). Decreased tPA correlated with decreased total body and visceral fat (r = 0.28, p = 0.05; r = 0.38, p = 0.008) and increased QUICKI (r = -0.38, p = 0.007). CONCLUSIONS While exercise resulted in improved fitness, body composition, and glycemic control, there were no changes in FMD or circulating endothelial biomarkers. The associations of changes in cardiovascular risk factors and endothelial biomarkers suggest that improvement in risk factors could mediate the exercise-induced improvements in endothelial function seen in prior studies.
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Affiliation(s)
- Bethany Barone Gibbs
- Department of Epidemiology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
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