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Sautillet B, Bourdillon N, Millet GP, Lemaître F, Cozette M, Delanaud S, Ahmaïdi S, Costalat G. Hot water immersion: Maintaining core body temperature above 38.5°C mitigates muscle fatigue. Scand J Med Sci Sports 2024; 34:e14503. [PMID: 37747708 DOI: 10.1111/sms.14503] [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: 03/28/2023] [Revised: 09/06/2023] [Accepted: 09/15/2023] [Indexed: 09/26/2023]
Abstract
PURPOSE Hot water immersion (HWI) has gained popularity to promote muscle recovery, despite limited data on the optimal heat dose. The purpose of this study was to compare the responses of two exogenous heat strains on core body temperature, hemodynamic adjustments, and key functional markers of muscle recovery following exercise-induced muscle damage (EIMD). METHODS Twenty-eight physically active males completed an individually tailored EIMD protocol immediately followed by one of the following recovery interventions: HWI (40°C, HWI40 ), HWI (41°C, HWI41 ) or warm water immersion (36°C, CON36 ). Gastrointestinal temperature (Tgi ), hemodynamic adjustments (cardiac output [CO], mean arterial pressure [MAP], and systemic vascular resistance [SVR]), pre-frontal cortex deoxyhemoglobin (HHb), ECG-derived respiratory frequency, and subjective perceptual measures were tracked throughout immersion. In addition, functional markers of muscle fatigue (maximal concentric peak torque [Tpeak ]) and muscle damage (late-phase rate of force development [RFD100-200 ]) were measured prior to EIMD (pre-), 24 h (post-24 h), and 48 h (post-48 h) post-EIMD. RESULTS By the end of immersion, HWI41 led to significantly higher Tgi values than HWI40 (38.8 ± 0.1 vs. 38.0°C ± 0.6°C, p < 0.001). While MAP was well maintained throughout immersion, only HWI41 led to increased (HHb) (+4.2 ± 1.47 μM; p = 0.005) and respiratory frequency (+4.0 ± 1.21 breath.min-1 ; p = 0.032). Only HWI41 mitigated the decline in RFD100-200 at post-24 h (-7.1 ± 31.8%; p = 0.63) and Tpeak at post-48 h (-3.1 ± 4.3%, p = 1). CONCLUSION In physically active males, maintaining a core body temperature of ~25 min within the range of 38.5°C-39°C has been found to be effective in improving muscle recovery, while minimizing the risk of excessive physiological heat strain.
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Affiliation(s)
- Benoît Sautillet
- Faculty of Sport Sciences, APERE Laboratory, UR 3300, University of Picardie Jules Verne, Amiens, France
| | - Nicolas Bourdillon
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Fréderic Lemaître
- Faculty of Sport Sciences, CETAPS Laboratory, UR 3832, Normandy University, Rouen, France
| | - Maryne Cozette
- Faculty of Sport Sciences, APERE Laboratory, UR 3300, University of Picardie Jules Verne, Amiens, France
| | - Stéphane Delanaud
- PériTox UMR_I 01 laboratory, CURS-UPJV, F-80054, University of Picardie Jules Verne, Amiens, France
| | - Saïd Ahmaïdi
- Faculty of Sport Sciences, APERE Laboratory, UR 3300, University of Picardie Jules Verne, Amiens, France
| | - Guillaume Costalat
- Faculty of Sport Sciences, APERE Laboratory, UR 3300, University of Picardie Jules Verne, Amiens, France
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Marriott RJ, Singh B, McArdle N, Darcey E, King S, Bond-Smith D, Reynor A, Noffsinger W, Ward K, Mukherjee S, Hillman DR, Cadby G. Does OSA Increase Risk for Cancer?: A Large Historical Sleep Clinic Cohort Study. Chest 2023; 164:1042-1056. [PMID: 37150506 DOI: 10.1016/j.chest.2023.04.043] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 04/25/2023] [Indexed: 05/09/2023] Open
Abstract
BACKGROUND The relationship between OSA and cancer is unclear. RESEARCH QUESTION What is the association between OSA and cancer prevalence and incidence in a large Western Australian sleep clinic cohort (N = 20,289)? STUDY DESIGN AND METHODS OSA severity was defined by apnea-hypopnea index (AHI) and nocturnal hypoxemia (duration and percentage at oxygen saturation < 90%) measured by in-laboratory polysomnogram. Measures of potential confounding included age, sex, BMI, smoking status, socioeconomic status, and BP. Outcomes were determined from the Western Australian cancer and death registries. Analyses were confined within periods using consistent AHI scoring criteria: January 1, 1989, to July 31, 2002 (American Sleep Disorders Association criteria), and August 1, 2002, to June 30, 2013 (Chicago criteria). We examined associations of AHI and nocturnal hypoxemia with cancer prevalence using logistic regression and cancer incidence using Cox regression analyses. RESULTS Cancer prevalence at baseline was 329 of 10,561 in the American Sleep Disorders Association period and 633 of 9,728 in the Chicago period. Nocturnal hypoxemia but not AHI was independently associated with prevalent cancer following adjustment for participant age, sex, BMI, smoking status, socioeconomic status, and BP. Of those without prevalent cancer, cancer was diagnosed in 1,950 of 10,232 (American Sleep Disorders Association) and 623 of 9,095 (Chicago) participants over a median follow-up of 11.2 years. Compared with the reference category (no OSA, AHI < 5 events per hour), univariable models estimated higher hazard ratios for cancer incidence for mild (AHI 5-15 events per hour), moderate (AHI 15.1-30 events per hour), and severe (AHI > 30 events per hour) OSA. Multivariable analyses consistently revealed associations between age and, in some cases, sex, BMI, and smoking status, with cancer incidence. After adjusting for confounders, multivariable models showed no independent association between OSA severity and increased cancer incidence. INTERPRETATION Nocturnal hypoxemia is independently associated with prevalent cancer. OSA severity is associated with incident cancer, although this association seems secondary to other risk factors for cancer development. OSA is not an independent risk factor for cancer incidence.
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Affiliation(s)
- Ross J Marriott
- School of Population and Global Health, University of Western Australia, Crawley, WA, Australia
| | - Bhajan Singh
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia; Department of Pulmonary Physiology & Sleep Medicine, West Australian Sleep Disorders Research Institute, Sir Charles Gairdner Hospital, Nedlands, WA, Australia.
| | - Nigel McArdle
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia; Department of Pulmonary Physiology & Sleep Medicine, West Australian Sleep Disorders Research Institute, Sir Charles Gairdner Hospital, Nedlands, WA, Australia
| | - Ellie Darcey
- School of Population and Global Health, University of Western Australia, Crawley, WA, Australia
| | - Stuart King
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia; Department of Pulmonary Physiology & Sleep Medicine, West Australian Sleep Disorders Research Institute, Sir Charles Gairdner Hospital, Nedlands, WA, Australia
| | - Daniela Bond-Smith
- School of Population and Global Health, University of Western Australia, Crawley, WA, Australia; University of Hawaii Economic Research Organization, University of Hawaii at Mānoa, Honolulu, Hawaii
| | - Ayesha Reynor
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia; Department of Pulmonary Physiology & Sleep Medicine, West Australian Sleep Disorders Research Institute, Sir Charles Gairdner Hospital, Nedlands, WA, Australia
| | - William Noffsinger
- Department of Pulmonary Physiology & Sleep Medicine, West Australian Sleep Disorders Research Institute, Sir Charles Gairdner Hospital, Nedlands, WA, Australia
| | - Kim Ward
- Department of Pulmonary Physiology & Sleep Medicine, West Australian Sleep Disorders Research Institute, Sir Charles Gairdner Hospital, Nedlands, WA, Australia
| | - Sutapa Mukherjee
- Flinders Health and Medical Research Institute and Adelaide Institute for Sleep Health, Flinders University, Adelaide, SA, Australia; Respiratory and Sleep Services, Southern Adelaide Local Health Network, SA Health, Adelaide, SA, Australia
| | - David R Hillman
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia; Department of Pulmonary Physiology & Sleep Medicine, West Australian Sleep Disorders Research Institute, Sir Charles Gairdner Hospital, Nedlands, WA, Australia
| | - Gemma Cadby
- School of Population and Global Health, University of Western Australia, Crawley, WA, Australia
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Martínez-Díaz IC, Carrasco Páez L. Little but Intense: Using a HIIT-Based Strategy to Improve Mood and Cognitive Functioning in College Students. Healthcare (Basel) 2023; 11:1880. [PMID: 37444715 DOI: 10.3390/healthcare11131880] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/24/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
Looking for useful and motivational strategies for promoting healthy habits and improving cognitive functioning in young populations, the aim of the present study was to determine if a single bout of high-intensity interval exercise could stimulate mood and working memory in college students. A total of 25 male subjects (mean ± SD, age: 21.7 ± 2.1 years; height: 1.77 ± 0.06 m; weight: 72.6 ± 8.4 kg; body mass index: 23.1 ± 1.4 kg/m2; VO2peak: 47.1 ± 9.3 mL/kg/min) participated voluntarily in this study. Participants underwent a high-intensity interval exercise consisting of 10 × 1 min of cycling at VO2peak power output. The Profile of Mood States (POMS) questionnaire and Digit Span Test (DST) were administered at three assessment time points: (a) pre-intervention assessment, (b) post-intervention assessment, and (c) 30 min post-intervention. The mood states decreased significantly after exercise; however, a significant increase in mood was found after 30 min of recovery. A significant post-exercise increase in DST performance was observed; moreover, DST scores obtained 30 min after exercise remained higher than those assessed pre-exercise. In conclusion, a single bout of HIIT induces acute positive changes in mood states in male college students and seems to be a powerful stimulus for cognitive functioning.
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Affiliation(s)
| | - Luis Carrasco Páez
- BIOFANEX Research Group, Department of Physical Education and Sports, University of Seville, E-41013 Seville, Spain
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Jacobs E, Rolnick N, Wezenbeek E, Stroobant L, Capelleman R, Arnout N, Witvrouw E, Schuermans J. Investigating the autoregulation of applied blood flow restriction training pressures in healthy, physically active adults: an intervention study evaluating acute training responses and safety. Br J Sports Med 2023:bjsports-2022-106069. [PMID: 36604156 DOI: 10.1136/bjsports-2022-106069] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/29/2022] [Indexed: 01/07/2023]
Abstract
OBJECTIVE To examine the effects of autoregulated (AUTO) and non-autoregulated (NAUTO) blood flow restriction (BFR) application on adverse effects, performance, cardiovascular and perceptual responses during resistance exercise. METHODS Fifty-six healthy participants underwent AUTO and NAUTO BFR resistance exercise in a randomised crossover design using a training session with fixed amount of repetitions and a training session until volitional failure. Cardiovascular parameters, rate of perceived effort (RPE), rate of perceived discomfort (RPD) and number of repetitions were investigated after training, while the presence of delayed onset muscle soreness (DOMS) was verified 24 hours post-session. Adverse events during or following training were also monitored. RESULTS AUTO outperformed NAUTO in the failure protocol (p<0.001), while AUTO scored significantly lower for DOMS 24 hours after exercise (p<0.001). Perceptions of effort and discomfort were significantly higher in NAUTO compared with AUTO in both fixed (RPE: p=0.014, RPD: p<0.001) and failure protocol (RPE: p=0.028, RPD: p<0.001). Sixteen adverse events (7.14%) were recorded, with a sevenfold incidence in the fixed protocol for NAUTO compared with AUTO (NAUTO: n=7 vs AUTO: n=1) and five (NAUTO) vs three (AUTO) adverse events in the failure protocol. No significant differences in cardiovascular parameters were found comparing both pressure applications. CONCLUSION Autoregulation appears to enhance safety and performance in both fixed and failure BFR-training protocols. AUTO BFR training did not seem to affect cardiovascular stress differently, but was associated with lower DOMS, perceived effort and discomfort compared with NAUTO. TRIAL REGISTRATION NUMBER NCT04996680.
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Affiliation(s)
- Ewoud Jacobs
- Department of Rehabilitation Sciences, Ghent University Faculty of Medicine and Health Sciences, Ghent, Belgium
| | - Nicholas Rolnick
- The Human Performance Mechanic, Lehman College, New York City, New York, USA
| | - Evi Wezenbeek
- Department of Rehabilitation Sciences, Ghent University Faculty of Medicine and Health Sciences, Ghent, Belgium
| | - Lenka Stroobant
- Department of Orthopaedics and Traumatology, Ghent University Hospital, Ghent, Belgium
| | - Robbe Capelleman
- Department of Rehabilitation Sciences, Ghent University Faculty of Medicine and Health Sciences, Ghent, Belgium
| | - Nele Arnout
- Department of Orthopaedics and Traumatology, Ghent University Hospital, Ghent, Belgium
| | - Erik Witvrouw
- Department of Rehabilitation Sciences, Ghent University Faculty of Medicine and Health Sciences, Ghent, Belgium
| | - Joke Schuermans
- Department of Rehabilitation Sciences, Ghent University Faculty of Medicine and Health Sciences, Ghent, Belgium
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Alves TC, Pugliesi Abdalla P, Bohn L, Da Silva LSL, dos Santos AP, Tasinafo Júnior MF, Rossini Venturini AC, Mota J, Lopes Machado DR. Acute and chronic cardiometabolic responses induced by resistance training with blood flow restriction in HIV patients. Sci Rep 2022; 12:16989. [PMID: 36216952 PMCID: PMC9550823 DOI: 10.1038/s41598-022-19857-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 09/06/2022] [Indexed: 12/29/2022] Open
Abstract
Resistance training with blood flow restriction (RTBFR) allows physically impaired people living with HIV (PWH) to exercise at lower intensities than traditional resistance training (TRT). But the acute and chronic cardiac and metabolic responses of PWH following an RTBFR protocol are unknown. The objective was to compare the safety of acute and chronic effects on hemodynamic and lipid profiles between TRT or RTBFR in PWH. In this randomized control trial, 14 PWH were allocated in RTBFR (GRTBFR; n = 7) or TRT (GTRT; n = 7). Both resistance training protocols had 36 sessions (12 weeks, three times per week). Protocol intensity was 30% (GRTBFR) and 80% (GTRT). Hemodynamic (heart rate, blood pressure) and lipid profile were acutely (rest and post exercise 7th, 22nd, and 35th sessions) and chronically (pre and post-program) recorded. General linear models were applied to determine group * time interaction. In the comparisons between groups, the resistance training program showed acute adaptations: hemodynamic responses were not different (p > 0.05), regardless of the assessment session; and chronicles: changes in lipidic profile favors GRTBFR, which significantly lower level of total cholesterol (p = 0.024), triglycerides (p = 0.002) and LDL (p = 0.030) compared to GTRT. RTBFR and TRT induced a similar hemodynamic adaptation in PWH, with no significant risks of increased cardiovascular stress. Additionally, RTBFR promoted better chronic adequacy of lipid profile than TRT. Therefore, RTBFR presents a safe resistance training alternative for PWH.Trial registration: ClinicalTrials.gov ID: NCT02783417; Date of registration: 26/05/2016.
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Affiliation(s)
- Thiago Cândido Alves
- grid.11899.380000 0004 1937 0722Universidade de São Paulo, Avenue of Bandeirantes no 3900, University Campus-Monte Alegre, Ribeirão Preto, SP 14040-902 Brazil
| | - Pedro Pugliesi Abdalla
- grid.11899.380000 0004 1937 0722Universidade de São Paulo, Avenue of Bandeirantes no 3900, University Campus-Monte Alegre, Ribeirão Preto, SP 14040-902 Brazil ,grid.5808.50000 0001 1503 7226Universidade do Porto, Porto, Portugal
| | - Lucimere Bohn
- grid.5808.50000 0001 1503 7226Universidade do Porto, Porto, Portugal ,grid.410936.90000 0001 2199 9085Universidade Lusófona do Porto, Porto, Portugal
| | - Leonardo Santos Lopes Da Silva
- grid.11899.380000 0004 1937 0722Universidade de São Paulo, Avenue of Bandeirantes no 3900, University Campus-Monte Alegre, Ribeirão Preto, SP 14040-902 Brazil
| | - André Pereira dos Santos
- grid.11899.380000 0004 1937 0722Universidade de São Paulo, Avenue of Bandeirantes no 3900, University Campus-Monte Alegre, Ribeirão Preto, SP 14040-902 Brazil
| | - Márcio Fernando Tasinafo Júnior
- grid.11899.380000 0004 1937 0722Universidade de São Paulo, Avenue of Bandeirantes no 3900, University Campus-Monte Alegre, Ribeirão Preto, SP 14040-902 Brazil
| | - Ana Cláudia Rossini Venturini
- grid.11899.380000 0004 1937 0722Universidade de São Paulo, Avenue of Bandeirantes no 3900, University Campus-Monte Alegre, Ribeirão Preto, SP 14040-902 Brazil
| | - Jorge Mota
- grid.5808.50000 0001 1503 7226Universidade do Porto, Porto, Portugal
| | - Dalmo Roberto Lopes Machado
- grid.11899.380000 0004 1937 0722Universidade de São Paulo, Avenue of Bandeirantes no 3900, University Campus-Monte Alegre, Ribeirão Preto, SP 14040-902 Brazil ,grid.5808.50000 0001 1503 7226Universidade do Porto, Porto, Portugal
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Joyce KE, Balanos GM, Bradley C, Fountain A, Bradwell AR, Lucas SJE. Post-exercise urinary alpha-1 acid glycoprotein is not dependent on hypoxia. J Appl Physiol (1985) 2021; 132:261-269. [PMID: 34762527 PMCID: PMC8791839 DOI: 10.1152/japplphysiol.00476.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Proteinuria is a transient physiological phenomenon that occurs with a range of physical activities and during ascent to altitude. Exercise intensity appears to dictate the magnitude of postexercise proteinuria; however, evidence also indicates the possible contributions from exercise-induced hypoxemia or reoxygenation. Using an environmental hypoxic chamber, this crossover-designed study aimed to evaluate urinary alpha-1 acid glycoprotein (α1-AGP) excretion pre/postexercise performed in hypoxia (HYP) and normoxia (NOR). Sixteen individuals underwent experimental sessions in normoxia (NOR, 20.9% O2) and hypoxia (HYP, 12.0% O2). Sessions began with a 2-h priming period before completing a graded maximal exercise test (GXT) on a cycle ergometer, which was followed by continuation of exposure for an additional 2 h. Physiological responses (i.e., blood pressure, heart rate, and peripheral oxygenation), Lake Louise Scores (LLSs), and urine specimens (analyzed for albumin and α1-AGP) were collected pre- and postexercise (after 30, 60, and 120 min). Peak power output was significantly reduced in HYP (193 ± 45 W) compared with NOR (249 ± 59 W, P < 0.01). Postexercise urinary α1-AGP was greater in NOR (20.04 ± 14.84 µg·min−1) than in HYP (15.08 ± 13.46 µg·min−1), albeit the difference was not significant (P > 0.05). Changes in urinary α1-AGP from pre- to post-30 min were not related to physiological responses or performance outcomes observed during GXT in NOR or HYP. Despite profound systemic hypoxemia with maximal exercise in hypoxia, postexercise α1-AGP excretion was not elevated above the levels observed following normoxic exercise. NEW & NOTEWORTHY By superimposing hypoxic exposure and maximal exercise, we were able to investigate the impact of hypoxia on postexercise proteinuria. Urinalysis for α1-AGP (via particle-enhanced immunoturbidimetry) in specimens collected pre-/postexercise enabled the sensitive detection of altered glomerular permeability. Data indicated that exercise intensity, rather than the degree of exercise-induced hypoxemia, determines postexercise proteinuria.
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Affiliation(s)
- Kelsey Elizabeth Joyce
- School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - George M Balanos
- School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Christopher Bradley
- School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Amy Fountain
- Research & Development, The Binding Site Ltd, Birmingham, United Kingdom
| | - Arthur Randell Bradwell
- The Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Samuel J E Lucas
- School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
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Noninvasive carotid pressure-diameter loops to identify viscoelastic properties in ageing, hypertension and type 2 diabetes. J Hypertens 2021; 39:2307-2317. [PMID: 34620812 DOI: 10.1097/hjh.0000000000002918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Arterial stiffness as pulse wave velocity (PWV) predicts cardiovascular events independently of blood pressure (BP). PWV does not distinguish between stiffness in systole and diastole. This cross-sectional study aimed to test the hypothesis that viscous and elastic carotid wall properties differ between systole and diastole, distinguishing effects of ageing, hypertension and T2 diabetes (T2DM). METHODS We examined carotid visco-elasticity in 307 people (180 men), with hypertension alone (n = 69), combined hypertension/T2DM (H-T2DM, n = 99), normotensive (N-T2DM, n = 25) and healthy controls (n = 114). Diameter (D)/pressure (P) waveforms were measured at right /left common carotid arteries, respectively. Local carotid PWV and distensibility in systole and diastole were evaluated by the D2P-loop method, and wall viscosity from hysteresis, the area (HA) within the P--D loop, as a dynamic measure of systolic loading and diastolic unloading. RESULTS Controls' hysteresis fell quadratically with age (R2 = 0.23, P < 0.001). Yet mean HA in hypertensive patients (0.95, 95% CI 0.65-1.23) was six-fold higher than in age-matched controls (0.14, -0.20 to 0.49, P < 0.001) with a 2.5× difference between diastolic (dDs) to systolic (sDs) distensibility (P < 0.05) in hypertensive patients. HA was higher in hypertensive patients and H-T2DMs (0.80, 0.58-1.04) than N-T2DMs (0.20, -0.17 to 0.54, P < 0.05), but similar between controls and N-T2DMs. BP-adjusted carotid diameters in all T2DM were significantly greater compared with controls and hypertensive patients. CONCLUSION Higher BP increased wall viscosity, hysteresis and relative difference between systolic and diastolic distensibility across groups. Carotid diameters were increased in all T2DMs, more in H-T2DM, probably altering BP-flow dynamics in T2DM.
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Angius L, Pageaux B, Crisafulli A, Hopker J, Marcora SM. Ischemic preconditioning of the muscle reduces the metaboreflex response of the knee extensors. Eur J Appl Physiol 2021; 122:141-155. [PMID: 34596759 PMCID: PMC8748374 DOI: 10.1007/s00421-021-04815-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 09/16/2021] [Indexed: 11/25/2022]
Abstract
Purpose This study investigated the effect of ischemic preconditioning (IP) on metaboreflex activation following dynamic leg extension exercise in a group of healthy participants. Method Seventeen healthy participants were recruited. IP and SHAM treatments (3 × 5 min cuff occlusion at 220 mmHg or 20 mmHg, respectively) were administered in a randomized order to the upper part of exercising leg’s thigh only. Muscle pain intensity (MP) and pain pressure threshold (PPT) were monitored while administrating IP and SHAM treatments. After 3 min of leg extension exercise at 70% of the maximal workload, a post-exercise muscle ischemia (PEMI) was performed to monitor the discharge group III/IV muscle afferents via metaboreflex activation. Hemodynamics were continuously recorded. MP was monitored during exercise and PEMI. Results IP significantly reduced mean arterial pressure compared to SHAM during metaboreflex activation (mean ± SD, 109.52 ± 7.25 vs. 102.36 ± 7.89 mmHg) which was probably the consequence of a reduced end diastolic volume (mean ± SD, 113.09 ± 14.25 vs. 102.42 ± 9.38 ml). MP was significantly higher during the IP compared to SHAM treatment, while no significant differences in PPT were found. MP did not change during exercise, but it was significantly lower during the PEMI following IP (5.10 ± 1.29 vs. 4.00 ± 1.54). Conclusion Our study demonstrated that IP reduces hemodynamic response during metaboreflex activation, while no effect on MP and PPT were found. The reduction in hemodynamic response was likely the consequence of a blunted venous return.
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Affiliation(s)
- Luca Angius
- Faculty of Health and Life Sciences, Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle upon Tyne, UK.
- Endurance Research Group, School of Sport and Exercise Sciences, University of Kent, Chatham Maritime, UK.
| | - Benjamin Pageaux
- École de Kinésiologie et des Sciences de l'Activité Physique (EKSAP), Faculté de Médicine, Université de Montréal, Montréal, QC, Canada
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, QC, Canada
| | - Antonio Crisafulli
- The Department of Medical Sciences, Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy
| | - James Hopker
- Endurance Research Group, School of Sport and Exercise Sciences, University of Kent, Chatham Maritime, UK
| | - Samuele Maria Marcora
- Endurance Research Group, School of Sport and Exercise Sciences, University of Kent, Chatham Maritime, UK
- Department of Biomedical and NeuroMotor Sciences (DiBiNeM), University of Bologna, Bologna, Italy
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The effect of heart rate and pulse pressure on mean arterial pressure: the combined formula for calculation of mean arterial pressure. Blood Press Monit 2021; 26:373-379. [PMID: 34054029 DOI: 10.1097/mbp.0000000000000548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND We demonstrate a new formula to predict mean arterial pressure (MAP) using corrections of the key factors associated with the inaccuracy of the standard formula: heart rate (HR) and pulse pressure (PP). METHODS A total of 99 patients (50 men, 49 women; mean age 52.5 ± 10.3 years), who underwent elective coronary angiography, were enrolled in our study. The arterial pressure was measured in the aortic root. MAP was measured digitally by the area-under-the-pressure-time curve method. We evaluated the accuracy of four different formulas: the standard formula, the formula of Razminia et al., the formula of Meaney et al. and the combined formula. RESULTS PP coefficient deviation of the standard formula was negatively correlated with PP (R = -0,561, P < 0.001), and positively correlated with HR (R = 0,298, P = 0.003). Both R and R2 values of the combined formula were higher than previous formulas. Accuracy parameters of the combined formula [root mean square error (RMSE): 1.801 mmHg, mean square residuals (MSR): 3.244 mmHg2, Akaike information criterion (AIC): 401.4] were superior to the standard formula (RMSE: 1.902 mmHg, MSR: 3.620 mmHg2, AIC: 412.3), the formula of Razminia et al. (RMSE: 2.022 mmHg, MSR: 4.089 mmHg2, AIC: 424.3) and the formula of Meaney et al. (RMSE: 2.137 mmHg, MSR: 4.568 mmHg2, AIC: 435.3). In the multivariate linear regression analysis, the combined formula was the only method that independently predicts the measured MAP (beta = 0,990, P < 0.001). CONCLUSION The combined formula is superior to previous formulas for accurately predicting MAP.
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Errors and Consequences of Inaccurate Estimation of Mean Blood Flow Velocity in Cerebral Arteries. ACTA NEUROCHIRURGICA. SUPPLEMENT 2021; 131:23-25. [PMID: 33839811 DOI: 10.1007/978-3-030-59436-7_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Many transcranial Doppler ultrasonography devices estimate the mean flow velocity (FVm) by using the traditional formula (FVsystolic + 2 × FVdiastolic)/3 instead of a more accurate formula calculating it as the time integral of the current flow velocities divided by the integration period. We retrospectively analyzed flow velocity and intracranial pressure signals containing plateau waves (transient intracranial hypertension), which were collected from 14 patients with a traumatic brain injury. The differences in FVm and its derivative pulsatility index (PI) calculated with the two different methods were determined. We found that during plateau waves, when the intracranial pressure (ICP) rose, the error in FVm and PI increased significantly from the baseline to the plateau (from 4.6 ± 2.4 to 9.8 ± 4.9 cm/s, P < 0.05). Similarly, the error in PI also increased during plateau waves (from 0.11 ± 0.07 to 0.44 ± 0.24, P < 0.005). These effects were most likely due to changes in the pulse waveform during increased ICP, which alter the relationship between systolic, diastolic, and mean flow velocities. If a change in the mean ICP is expected, then calculation of FVm with the traditional formula is not recommended.
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11
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Fujii N, Fujimoto T, Yinhang C, Dobashi K, Matsutake R, Amano T, Watanabe K, Nishiyasu T. Caffeine Exacerbates Hyperventilation and Reductions in Cerebral Blood Flow in Physically Fit Men Exercising in the Heat. Med Sci Sports Exerc 2021; 53:845-852. [PMID: 33044440 DOI: 10.1249/mss.0000000000002537] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Caffeine is an exercise performance enhancer widely used by individuals engaged in training or competition under heat-stressed conditions. Caffeine ingestion during exercise in the heat is believed to be safe because it does not greatly affect body temperature responses, heart rate, or body fluid status. However, it remains unknown whether caffeine affects hyperthermia-induced hyperventilation or reductions in the cerebral blood flow index. We tested the hypothesis that under conditions inducing severe hyperthermia, caffeine exacerbates hyperthermia-induced hyperventilation and reduces the cerebral blood flow index during exercise. METHODS Using a randomized, single-blind, crossover design, 12 physically active healthy young men (23 ± 2 yr) consumed a moderate dose of caffeine (5 mg·kg-1) or placebo in the heat (37°C). Approximately 60 min after the ingestion, they cycled for ~45 min at a workload equal to ~55% of their predetermined peak oxygen uptake (moderate intensity) until their core temperature increased to 2.0°C above its preexercise baseline level. RESULTS In both trials, ventilation increased and the cerebral blood flow index assessed by middle cerebral artery mean blood velocity decreased as core temperature rose during exercise (P < 0.05), indicating that hyperthermia-induced hyperventilation and lowering of the cerebral blood flow occurred. When core temperature was elevated by 1.5°C or more (P < 0.05), ventilation was higher and the cerebral blood flow was lower throughout the caffeine trial than the placebo trial (P < 0.05). CONCLUSIONS A moderate dose of caffeine exacerbates hyperthermia-induced hyperventilation and reductions in the cerebral blood flow index during exercise in the heat with severe hyperthermia.
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Affiliation(s)
- Naoto Fujii
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, JAPAN
| | | | | | - Kohei Dobashi
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, JAPAN
| | - Ryoko Matsutake
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, JAPAN
| | - Tatsuro Amano
- Laboratory for Exercise and Environmental Physiology, Faculty of Education, Niigata University, Niigata, JAPAN
| | - Koichi Watanabe
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, JAPAN
| | - Takeshi Nishiyasu
- Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, JAPAN
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12
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Zarehoseinzade E, Allami A, Ahmadi M, Bijani B, Mohammadi N. Finasteride in hospitalized adult males with COVID-19: A risk factor for severity of the disease or an adjunct treatment: A randomized controlled clinical trial. Med J Islam Repub Iran 2021; 35:30. [PMID: 34169042 PMCID: PMC8214036 DOI: 10.47176/mjiri.35.30] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Indexed: 01/19/2023] Open
Abstract
Background: There is controversy about the efficacy of 5-alpha-reductase inhibitors in COVID-19 patients. Some assumed that finasteride might be a risk factor for deterioration and others proposed it as a possible adjunct treatment for moderate to severe COVID-19 infection in the elderly.
Methods: We performed a randomized controlled clinical trial (registration ID IRCT20200505047318N1) on 80 hospitalized male patients aged ≥50 years diagnosed with COVID-19 pneumonia in a tertiary hospital in Qazvin (Iran) from April to July 2020. The patients were randomized into one of the 2 treatment groups using simple randomization. Treatment group patients underwent routine drug therapy and 5 mg finasteride once daily for 7 days. The primary endpoint was mortality rate and length of hospital stay (LOS), and secondary endpoints were peripheral capillary oxygen saturation, respiratory rate, and inflammatory markers changes. The study protocol was approved by the medical ethics committee of Qazvin University of Medical Sciences (registration ID IR.QUMS.REC.1399.080). Data were analyzed by statistical tests and SPSS version 25. Also, p<0.05 was considered to be statistically significant.
Results: We found a significant difference on O2 saturation among the 2 study groups on fifth day compared with the admission time (p= 0.018). The results did not show significant differences in mortality rate (2.5% vs 10%; p= 0.166) and LOS (p= 0.866) between patients in the finasteride and the control group.
Conclusion: A short course of finasteride administration partially improves O2 saturation but does not influence other outcomes in hospitalized male patients aged ≥50 years with COVID-19 pneumonia. Further research in a large scale with longer follow-up is required to help clarify the role of finasteride in this setting.
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Affiliation(s)
- Elham Zarehoseinzade
- Department of Infectious Diseases, Clinical Research Development Unit, BouAli Sina Hospital, Qazvin University of Medical of Sciences, Qazvin, Iran
| | - Abbas Allami
- Department of Infectious Diseases, Clinical Research Development Unit, BouAli Sina Hospital, Qazvin University of Medical of Sciences, Qazvin, Iran
| | | | - Behzad Bijani
- Department of Infectious Diseases, Clinical Research Development Unit, BouAli Sina Hospital, Qazvin University of Medical of Sciences, Qazvin, Iran
| | - Navid Mohammadi
- Children Growth Research Center, Research Institute for Prevention of Non-Communicable Diseases, Qazvin University of Medical Sciences, Qazvin, Iran.,Canada Optimax Access Consultation, Ottawa, Canada
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13
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Wingo JE, Stone T, Ng J. Cardiovascular Drift and Maximal Oxygen Uptake during Running and Cycling in the Heat. Med Sci Sports Exerc 2021; 52:1924-1932. [PMID: 32102057 DOI: 10.1249/mss.0000000000002324] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Greater cardiovascular (CV) drift occurs during cycling compared to running in temperate conditions. CV drift also corresponds to proportional reductions in maximal oxygen uptake (V˙O2max) during heat stress. Whether exercise mode differentially affects CV drift-and accompanying declines in V˙O2max-during heat stress is uncertain. The purpose of this study was to test the hypothesis that a greater magnitude of CV drift, accompanied by a greater decrement in V˙O2max, occurs during cycling compared to running in hot conditions. METHODS 7 active men (mean ± SD; age = 25 ± 6 yr, percent body fat = 11.9% ± 2.4%) completed a control graded exercise test (GXT) on a cycle ergometer and treadmill. Then on separate, counterbalanced occasions they completed 15 or 45 min of cycling or running at 60% V˙O2max in 35°C, immediately followed by a GXT to measure V˙O2max (4 trials total). The separate 15- and 45-min trials were designed to measure CV drift and V˙O2max over the same time interval. RESULTS Heart rate increased 19% and 17% and stroke volume decreased 20% and 15% between 15 and 45 min during running and cycling, respectively, but modes were not different (all P > 0.05). Despite a 1.8°C larger core-to-skin thermal gradient during running, decrements in V˙O2peak were not different between exercise modes (95% CI for difference in change scores between 15 and 45 min: -0.2, 0.3). CONCLUSIONS CV strain (indexed as CV drift) during prolonged exercise in the heat corresponds to reduced V˙O2max, irrespective of exercise mode or the thermal gradient. As such, the upward drift in heart rate associated with CV drift reflects increased relative metabolic intensity (%V˙O2max) during prolonged cycling or running in the heat.
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Affiliation(s)
- Jonathan E Wingo
- Department of Kinesiology, The University of Alabama, Tuscaloosa, AL
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14
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Menstrual cycle effects on cardiovascular drift and maximal oxygen uptake during exercise heat stress. Eur J Appl Physiol 2020; 121:561-572. [PMID: 33156415 DOI: 10.1007/s00421-020-04542-y] [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] [Received: 05/13/2020] [Accepted: 10/24/2020] [Indexed: 10/23/2022]
Abstract
AIM Compared to other modulators of physiological strain associated with exercise heat stress, hyperthermia results in the greatest magnitude of cardiovascular (CV) drift and associated decrements in maximal oxygen uptake ([Formula: see text]). PURPOSE To determine if elevated core temperature in the luteal phase (LP) of the menstrual cycle results in greater CV drift and reductions in [Formula: see text] versus the follicular phase (FP). METHODS Seven women performed 15- and 45-min cycling bouts on separate occasions (60% [Formula: see text], 35 °C) followed by a [Formula: see text] test during the FP and LP. CV drift was measured between 15 and 45 min during the 45-min bout, and the 15-min bout was for measuring [Formula: see text] over the same time interval that CV drift occurred. RESULTS Core temperature during LP was ~ 0.3 °C higher than FP (P < 0.05), but changes from rest during exercise were similar between phases (all P > 0.05). Heart rate increased significantly over time but was not different between phases (P = 0.78). Stroke volume decreased more over time during LP compared to FP (P = 0.02), but the values were similar at the end of exercise between phases (both time points P > 0.05). [Formula: see text] decrements for FP (13%) and LP (16%) were also comparable (P = 0.97). CONCLUSIONS The LP-FP difference in core temperature in this study was not sufficient to amplify CV strain and decrements in [Formula: see text]. Greater differences in core temperature may be required to independently modulate CV drift and accompanying decrements in [Formula: see text] during prolonged exercise heat stress.
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15
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Pugliese NR, De Biase N, Conte L, Gargani L, Mazzola M, Fabiani I, Natali A, Dini FL, Frumento P, Rosada J, Taddei S, Borlaug BA, Masi S. Cardiac Reserve and Exercise Capacity: Insights from Combined Cardiopulmonary and Exercise Echocardiography Stress Testing. J Am Soc Echocardiogr 2020; 34:38-50. [PMID: 33036818 DOI: 10.1016/j.echo.2020.08.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/13/2020] [Accepted: 08/13/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Cardiopulmonary exercise testing (CPET) represents the gold standard to estimate peak oxygen consumption (VO2) noninvasively. To improve the analysis of the mechanisms behind effort intolerance, we examined whether exercise stress echocardiography measurements relate to directly measured peak VO2 during exercise in a large cohort of patients within the heart failure (HF) spectrum. METHODS We performed a symptom-limited graded ramp bicycle CPET exercise stress echocardiography in 30 healthy controls and 357 patients: 113 at risk of developing HF (American College of Cardiology/American Heart Association stage A-B) and 244 in HF stage C with preserved (HFpEF, n = 101) or reduced ejection fraction (HFrEF, n = 143). RESULTS Peak VO2 significantly decreased from controls (23, 21.7-29.7 mL/kg/minute; median, interquartile range) to stage A-B (18, 15.4-20.7 mL/kg/minute) and stage C (HFpEF: 13.6, 11.8-16.8 mL/kg/minute; HFrEF: 14.2, 10.7-17.5 mL/kg/minute). A regression model to predict peak VO2 revealed that peak left ventricular (LV) systolic annulus tissue velocity (S'), peak tricuspid annular plane systolic excursion/systolic pulmonary artery pressure (right ventricle-pulmonary artery coupling), and low-load left atrial (LA) reservoir strain/E/e' (LA compliance) were independent predictors, in addition to peak heart rate, stroke volume, and workload (adjusted R2 = 0.76, P < .0001). The model was successfully tested in subjects with atrial fibrillation (n = 49) and with (n = 224) and without (n = 163) beta-blockers (all P < .01). Peak S' showed the highest accuracy in predicting peak VO2 < 10 mL/kg/minute (cut point ≤ 7.5 cm/sec, area under the curve = 0.92, P < .0001) and peak VO2 > 20 mL/kg/minute (cut point > 12.5 cm/sec, area under the curve = 0.84, P < .0001) in comparison with the other cardiac variables of the model (P < .05). CONCLUSIONS Peak VO2 is directly related to measures of LV systolic function, LA compliance, and right ventricle-pulmonary artery coupling, in addition to heart rate and stroke volume and independently of workload, age, and sex. The evaluation of cardiac mechanics may provide more insights into the causes of effort intolerance in subjects from HF stages A-C.
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Affiliation(s)
| | - Nicolò De Biase
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Lorenzo Conte
- Cardiology Unit, Ospedale Castelnuovo Garfagnana, Pisa, Italy
| | - Luna Gargani
- Institute of Clinical Physiology, C.N.R., Pisa, Italy
| | - Matteo Mazzola
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | - Andrea Natali
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Frank L Dini
- Area Cardiologica, Casa di Cura Villa Esperia, Salice Terme, Pavia, Italy
| | - Paolo Frumento
- Department of Political Sciences, University of Pisa, Pisa, Italy
| | - Javier Rosada
- Fourth Unit of Internal Medicine, University Hospital of Pisa, Pisa, Italy
| | - Stefano Taddei
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Barry A Borlaug
- Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, Minnesota
| | - Stefano Masi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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16
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Pugliese NR, Fabiani I, Santini C, Rovai I, Pedrinelli R, Natali A, Dini FL. Value of combined cardiopulmonary and echocardiography stress test to characterize the haemodynamic and metabolic responses of patients with heart failure and mid-range ejection fraction. Eur Heart J Cardiovasc Imaging 2020; 20:828-836. [PMID: 30753369 DOI: 10.1093/ehjci/jez014] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/11/2019] [Accepted: 01/21/2019] [Indexed: 12/19/2022] Open
Abstract
AIMS To characterize heart failure (HF) with mid-range ejection fraction (HFmrEF), combining cardiopulmonary exercise test, and exercise stress echocardiography. METHODS AND RESULTS We studied 169 consecutive subjects (age 62.3 ± 11 years; 74% male): 30 healthy controls, 45 patients with HF and preserved EF (HFpEF), 40 HFmrEF, and 54 with HF and reduced EF (HFrEF). Left ventricular (LV) stroke volume (SV), EF, elastance, global longitudinal strain, E/E', oxygen consumption (VO2), and arterial-venous oxygen content difference (AVO2diff) were measured in all exercise stages. HFmrEF revealed baseline features intermediate between HFrEF and HFpEF, except for B-type natriuretic peptide levels, which was similar to HFpEF and significantly lower than HFrEF. Peak VO2 was not significantly different between HF groups. HFrEF exhibited a significantly lower peak SV as compared to either HFpEF or HFmrEF (74.3 ± 21.8 mL vs. 88.0 ± 17.4 mL and 96.5 ± 25.1 mL; P < 0.01), whereas peak heart rate was not significantly different between HF groups. A significantly reduced AVO2diff at peak exercise was apparent in HFpEF and HFmrEF (15.2 ± 3.3 mL/dL and 13.3 ± 4.2 mL/dL) vs. HFrEF (17.±6.6 mL/dL; P < 0.01), whereas no significant difference was reported between HFpEF and HFmrEF. Multivariate analysis in the overall population and all groups revealed peak parameters as independent predictors of peak VO2 (R2 = 0.90, P < 0.0001); AVO2diff showed the largest standardized regression coefficient. CONCLUSION In HFpEF and HFmrEF, effort intolerance is predominantly due to peripheral factors (AVO2diff), whereas in HFrEF peak VO2 is restricted by low increases in SV. Individual therapy according to which component of VO2 is more impaired is advisable.
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Affiliation(s)
- Nicola Riccardo Pugliese
- Department of Surgical, Medical, Molecular Pathology and Critical Area, University of Pisa, Via Paradisa, 2, Pisa, Italy.,Cardiac, Thoracic and Vascular Department, University of Pisa, Via Paradisa, 2, Pisa, Italy
| | - Iacopo Fabiani
- Department of Surgical, Medical, Molecular Pathology and Critical Area, University of Pisa, Via Paradisa, 2, Pisa, Italy.,Cardiac, Thoracic and Vascular Department, University of Pisa, Via Paradisa, 2, Pisa, Italy
| | - Claudia Santini
- Cardiac, Thoracic and Vascular Department, University of Pisa, Via Paradisa, 2, Pisa, Italy
| | - Ilaria Rovai
- Cardiac, Thoracic and Vascular Department, University of Pisa, Via Paradisa, 2, Pisa, Italy
| | - Roberto Pedrinelli
- Cardiac, Thoracic and Vascular Department, University of Pisa, Via Paradisa, 2, Pisa, Italy
| | - Andrea Natali
- Department of Clinical and Experimental Medicine, University of Pisa, Via Paradisa, 2, Pisa, Italy
| | - Frank L Dini
- Cardiac, Thoracic and Vascular Department, University of Pisa, Via Paradisa, 2, Pisa, Italy
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17
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Bahnasawy S, Al-Sallami H, Duffull S. A minimal model to describe short-term haemodynamic changes of the cardiovascular system. Br J Clin Pharmacol 2020; 87:1411-1421. [PMID: 32886815 DOI: 10.1111/bcp.14541] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 08/15/2020] [Accepted: 08/21/2020] [Indexed: 12/28/2022] Open
Abstract
AIMS Current pharmacokinetic-pharmacodynamic models describing the haemodynamic changes often do not include necessary feedback mechanisms. These models provide adequate description of current data but may fail to adequately extrapolate to additional scenarios. This study aims to develop a minimal model to describe the short-term changes of haemodynamics that can be used as the basis for model development by future researchers. METHODS A minimal haemodynamic model was developed to describe the influence of drugs on blood pressure components. The model structure was defined based on known mechanisms and previously published models. The model was evaluated under 2 different simulation settings. The model parameters were calibrated to describe (without estimation) the haemodynamics of 2 antihypertensive drugs with data extracted from the literature. Structural identifiability analysis was done using various combinations of the observed variable. RESULTS The proposed model structure includes mean arterial pressure, heart rate and stroke volume and is composed of 4 states described by differential equations. Model evaluation showed flexibility in describing the haemodynamics at different target perturbations. Overlay plots of model predictions and literature data showed a good description without data fitting. The structural identifiability analysis revealed all model parameters and initial conditions were identifiable only when heart rate, mean arterial pressure and cardiac output were measured together. CONCLUSIONS A minimal model of the haemodynamic system was developed and evaluated. The model accounted for short-term haemodynamic feedback processes. We propose that this model can be used as the basis for future pharmacometric analyses of drugs acting on the haemodynamic system.
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Affiliation(s)
- Salma Bahnasawy
- Otago Pharmacometrics Group, School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Hesham Al-Sallami
- Otago Pharmacometrics Group, School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Stephen Duffull
- Otago Pharmacometrics Group, School of Pharmacy, University of Otago, Dunedin, New Zealand
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18
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Tseng PY, Chen YT, Wang CH, Chiu KM, Peng YS, Hsu SP, Chen KL, Yang CY, Lee OKS. Prediction of the development of acute kidney injury following cardiac surgery by machine learning. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2020; 24:478. [PMID: 32736589 PMCID: PMC7395374 DOI: 10.1186/s13054-020-03179-9] [Citation(s) in RCA: 162] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 07/14/2020] [Indexed: 12/14/2022]
Abstract
Background Cardiac surgery–associated acute kidney injury (CSA-AKI) is a major complication that results in increased morbidity and mortality after cardiac surgery. Most established prediction models are limited to the analysis of nonlinear relationships and fail to fully consider intraoperative variables, which represent the acute response to surgery. Therefore, this study utilized an artificial intelligence–based machine learning approach thorough perioperative data-driven learning to predict CSA-AKI. Methods A total of 671 patients undergoing cardiac surgery from August 2016 to August 2018 were enrolled. AKI following cardiac surgery was defined according to criteria from Kidney Disease: Improving Global Outcomes (KDIGO). The variables used for analysis included demographic characteristics, clinical condition, preoperative biochemistry data, preoperative medication, and intraoperative variables such as time-series hemodynamic changes. The machine learning methods used included logistic regression, support vector machine (SVM), random forest (RF), extreme gradient boosting (XGboost), and ensemble (RF + XGboost). The performance of these models was evaluated using the area under the receiver operating characteristic curve (AUC). We also utilized SHapley Additive exPlanation (SHAP) values to explain the prediction model. Results Development of CSA-AKI was noted in 163 patients (24.3%) during the first postoperative week. Regarding the efficacy of the single model that most accurately predicted the outcome, RF exhibited the greatest AUC (0.839, 95% confidence interval [CI] 0.772–0.898), whereas the AUC (0.843, 95% CI 0.778–0.899) of ensemble model (RF + XGboost) was even greater than that of the RF model alone. The top 3 most influential features in the RF importance matrix plot were intraoperative urine output, units of packed red blood cells (pRBCs) transfused during surgery, and preoperative hemoglobin level. The SHAP summary plot was used to illustrate the positive or negative effects of the top 20 features attributed to the RF. We also used the SHAP dependence plot to explain how a single feature affects the output of the RF prediction model. Conclusions In this study, machine learning methods were successfully established to predict CSA-AKI, which determines risks following cardiac surgery, enabling the optimization of postoperative treatment strategies to minimize the postoperative complications following cardiac surgeries.
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Affiliation(s)
- Po-Yu Tseng
- Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, No. 155, Section 2, Li-Nong Street, Beitou District, Taipei, 11221, Taiwan.,Stem Cell Research Center, National Yang-Ming University, Taipei, Taiwan.,Division of Nephrology, Department of Internal Medicine, Taipei City Hospital, Heping Fuyou Branch, Taipei, Taiwan
| | - Yi-Ting Chen
- Muen Biomedical and Optoelectronics Technologies Inc., New Taipei City, Taiwan
| | - Chuen-Heng Wang
- Muen Biomedical and Optoelectronics Technologies Inc., New Taipei City, Taiwan
| | - Kuan-Ming Chiu
- Division of Cardiovascular Surgery, Cardiovascular Center, Far Eastern Memorial Hospital, New Taipei City, Taiwan.,Department of Electrical Engineering, Yuan Ze University, Taoyuan City, Taiwan
| | - Yu-Sen Peng
- Division of Nephrology, Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan.,College of Electrical and Communication Engineering, Yuan Ze University, Taoyuan City, Taiwan.,Department of Applied Cosmetology, Lee-Ming Institute of Technology, New Taipei City, Taiwan
| | - Shih-Ping Hsu
- Division of Nephrology, Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Kang-Lung Chen
- Division of Cardiovascular Surgery, Cardiovascular Center, Far Eastern Memorial Hospital, New Taipei City, Taiwan.,Division of Cardiovascular Surgery, En Chu Kong Hospital, New Taipei City, Taiwan
| | - Chih-Yu Yang
- Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, No. 155, Section 2, Li-Nong Street, Beitou District, Taipei, 11221, Taiwan. .,Stem Cell Research Center, National Yang-Ming University, Taipei, Taiwan. .,Division of Nephrology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan. .,Center for Intelligent Drug Systems and Smart Bio-devices (IDS2B), Hsinchu, Taiwan.
| | - Oscar Kuang-Sheng Lee
- Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, No. 155, Section 2, Li-Nong Street, Beitou District, Taipei, 11221, Taiwan. .,Stem Cell Research Center, National Yang-Ming University, Taipei, Taiwan. .,China Medical University Hospital, Taichung, Taiwan.
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19
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Nielsen JH, Birukov A, Jensen RC, Kyhl HB, Jørgensen JS, Andersen MS, Glintborg D. Blood pressure and hypertension during pregnancy in women with polycystic ovary syndrome: Odense Child Cohort. Acta Obstet Gynecol Scand 2020; 99:1354-1363. [DOI: 10.1111/aogs.13914] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 05/07/2020] [Accepted: 05/10/2020] [Indexed: 12/26/2022]
Affiliation(s)
- Julie Hougård Nielsen
- Department of Endocrinology and Metabolism Odense University Hospital Odense Denmark
| | - Anna Birukov
- Charité – Universitätsmedizin BerlinCorporate member of Freie Universität BerlinHumboldt‐Universität zu Berlin, and Berlin Institute of Health Berlin Germany
- Department of Gynecology and Obstetrics Odense University Hospital Odense Denmark
- Experimental and Clinical Research Center, a joint cooperation between Max Delbrück Center for Molecular Medicine in the Helmholtz Association and Charité‐Universitätsmedizin Berlin Berlin Germany
- German Center for Cardiovascular Research (DZHK) Berlin Germany
- Department of Molecular Epidemiology German Institute of Human Nutrition Potsdam‐Rehbrücke Nuthetal Germany
| | - Richard Christian Jensen
- Department of Endocrinology and Metabolism Odense University Hospital Odense Denmark
- Department of Environmental Medicine University of Southern Denmark Odense Denmark
| | - Henriette Boye Kyhl
- Odense Child Cohort Hans Christian Andersen Children’s HospitalOdense University Hospital Odense Denmark
- OPEN Patient data Explorative Network (OPEN) University of Southern Denmark Odense Denmark
| | - Jan Stener Jørgensen
- Department of Gynecology and Obstetrics Odense University Hospital Odense Denmark
| | | | - Dorte Glintborg
- Department of Endocrinology and Metabolism Odense University Hospital Odense Denmark
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20
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Triggianese P, Cesareo M, Guarino MD, Conigliaro P, Chimenti MS, Cedola F, Mazzeo C, Nucci C, Perricone R. Evaluation of retinal microvascular perfusion in hereditary angioedema: a case-control study. Orphanet J Rare Dis 2020; 15:20. [PMID: 31952522 PMCID: PMC6969431 DOI: 10.1186/s13023-019-1263-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 11/22/2019] [Indexed: 11/30/2022] Open
Abstract
Evidence supports that hereditary angioedema (HAE) may be considered as a paroxysmal permeability disorder with defective but self-limiting endothelial barrier dysfunction. A potential subclinical abnormal vascular permeability at retinal capillaries could induce damage resulting in retinopathy. We aimed at exploring for the first time the presence of microangiopathy at retinal level from a highly selective cohort of patients with HAE due to C1 esterase inhibitor protein (C1INH) deficiency (type I). We conducted a pilot, prospective, case-control study including 20 type I HAE patients and 20 age−/sex-matched healthy controls (HC). All participants underwent standard ophthalmological examination including visual fields. Superficial and deep capillary plexi in the retina were analyzed by using new optical coherence tomography angiography (OCT-A). A total of 40 eyes from 20 HAE patients and 20 eyes from HC were evaluated. Perimetric indices of visual field were slightly worse in HAE than in controls. OCT-angiograms documented in HAE patients a lower retinal capillary density in both superficial and deep scans and a higher retinal thickness compared to healthy eyes. Our findings firstly documented subclinical abnormalities in retinal microvascular network in type I HAE patients that might be associated with early subtle functional changes. This preliminary evidence supports the hypothesis of a recurrent endothelial barrier failure at retinal level in HAE patients potentially resulting in chronic damage.
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Affiliation(s)
- Paola Triggianese
- Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy.
| | - Massimo Cesareo
- Ophthalmology Unit, Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy
| | - Maria Domenica Guarino
- Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy
| | - Paola Conigliaro
- Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy
| | - Maria Sole Chimenti
- Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy
| | - Francesca Cedola
- Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy
| | - Caterina Mazzeo
- Ophthalmology Unit, Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy
| | - Carlo Nucci
- Ophthalmology Unit, Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy
| | - Roberto Perricone
- Rheumatology, Allergology and Clinical Immunology, Department of "Medicina dei Sistemi", University of Rome Tor Vergata, Rome, Italy
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21
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Pugliese NR, Mazzola M, Fabiani I, Gargani L, De Biase N, Pedrinelli R, Natali A, Dini FL. Haemodynamic and metabolic phenotyping of hypertensive patients with and without heart failure by combining cardiopulmonary and echocardiographic stress test. Eur J Heart Fail 2020; 22:458-468. [PMID: 31950651 DOI: 10.1002/ejhf.1739] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 12/02/2019] [Accepted: 12/09/2019] [Indexed: 12/14/2022] Open
Abstract
AIM We combined cardiopulmonary exercise test (CPET) and exercise stress echocardiography (ESE) to identify early haemodynamic and metabolic alterations in patients with hypertension (HT) with and without heart failure with preserved ejection fraction (HFpEF). METHODS AND RESULTS Fifty stable HFpEF-HT outpatients (mean age 68 ± 14 years) on optimal medical therapy, 63 well-controlled HT subjects (mean age 63 ± 11 years) and 32 age and sex-matched healthy controls (mean age 59 ± 15 years) underwent a symptom-limited graded ramp bicycle CPET-ESE. The acquisition protocol included left ventricular cardiac output, global longitudinal strain, E/e', peak oxygen consumption (VO2 ), non-invasive arterial-venous oxygen content difference (AVO2 diff) and lung ultrasound B-lines. There was a decline in peak VO2 from controls (24.4 ± 3 mL/min/kg) to HFpEF-HT (15.2 ± 2 mL/min/kg), passing through HT (18.7 ± 2 mL/min/kg; P < 0.0001). HFpEF-HT displayed a lower peak cardiac output (9.8 ± 0.9 L/min) compared to HT (12.6 ± 1.0 L/min; P = 0.02) and controls (13.3 ± 1.0 L/min; P = 0.01). Peak AVO2 diff was reduced in HFpEF-HT and HT (13.3 ± 2 and 13.5 ± 2 mL/dL vs. controls: 16.9 ± 2 mL/dL; P < 0.0001). A different left ventricular contractility was observed among groups, expressed as low-load global longitudinal strain (-16.8 ± 5% in HFpEF-HT, -18.2 ± 3% in HT, and 20.9 ± 3% in controls; P < 0.0001), and distribution of E/e' and B-lines [HFpEF-HT: 13.7 ± 3 and 16, interquartile range (IQR) 10-22; HT: 9.5 ± 2 and 8, IQR 4-10; controls: 6.2 ± 2 and 0, IQR 0-2; P < 0.0001]. CONCLUSIONS Reduced peak VO2 values in HT with and without HFpEF may be the result of decreased AVO2 diff. CPET-ESE can also identify mild signs of left ventricular systo-diastolic dysfunction and pulmonary congestion, promoting advances in personalized therapy.
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Affiliation(s)
- Nicola R Pugliese
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Matteo Mazzola
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Iacopo Fabiani
- Cardiac, Thoracic and Vascular Department, University of Pisa, Pisa, Italy
| | - Luna Gargani
- Institute of Clinical Physiology - CNR, Pisa, Italy
| | - Nicolò De Biase
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Roberto Pedrinelli
- Cardiac, Thoracic and Vascular Department, University of Pisa, Pisa, Italy
| | - Andrea Natali
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Frank L Dini
- Cardiac, Thoracic and Vascular Department, University of Pisa, Pisa, Italy
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22
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Allen DR, Huang MU, Morris NB, Chaseling GK, Frohman EM, Jay O, Davis SL. Impaired Thermoregulatory Function during Dynamic Exercise in Multiple Sclerosis. Med Sci Sports Exerc 2019; 51:395-404. [PMID: 30779715 DOI: 10.1249/mss.0000000000001821] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
INTRODUCTION Impairments in sudomotor function during passive whole-body heating have been reported in multiple sclerosis (MS), a demyelinating disease of the CNS that disrupts autonomic function. However, the capability of the thermoregulatory system to control body temperature during exercise has never been assessed in MS. Thus, the aim of the present study was to test the hypothesis that thermoregulatory function is impaired in MS patients compared with healthy controls (CON) exercising at similar rates of metabolic heat production. METHODS Sweating and skin blood flow responses were compared between 12 individuals diagnosed with relapsing-remitting MS (9 females, 3 males) and 12 sex-, age-, mass-, and BSA-matched CON during a single bout of cycling exercise (rate of metabolic heat production: ∼4.5 W·kg) for 60 min in a climate-controlled room (25°C, 30% RH). RESULTS Individuals with MS exhibited an attenuated increase in cumulative whole-body sweat loss after 30 min (MS, 72 ± 51 g; CON, 104 ± 37 g; P = 0.04) and 60 min (MS, 209 ± 94 g; CON, 285 ± 62 g; P = 0.02), as well as lower sweating thermosensitivity (MS, 0.49 ± 0.26 mg·cm·min·°C; CON, 0.86 ± 0.30 mg·cm·min·°C; P = 0.049). Despite evidence for thermoregulatory dysfunction, there were no differences between MS and CON in esophageal or rectal temperatures at 30- or 60-min time points (P > 0.05). Cutaneous vasculature responses were also not different in MS compared with CON (P > 0.05). CONCLUSION Taken together, MS blunts sweating responses during exercise while cutaneous vasculature responses are preserved. Altered mechanisms of body temperature regulation in persons with MS may lead to temporary worsening of disease symptoms and limit exercise tolerance under more thermally challenging conditions.
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Affiliation(s)
- Dustin R Allen
- Applied Physiology and Wellness, Southern Methodist University, Dallas, TX.,Department of Health Sciences, Boston University, Boston, MA
| | - M U Huang
- Applied Physiology and Wellness, Southern Methodist University, Dallas, TX
| | - Nathan B Morris
- Thermal Ergonomics Laboratory, Faculty of Health Sciences, The University of Sydney, Lidcombe, NSW, AUSTRALIA
| | - Georgia K Chaseling
- Thermal Ergonomics Laboratory, Faculty of Health Sciences, The University of Sydney, Lidcombe, NSW, AUSTRALIA
| | - Elliot M Frohman
- Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Ollie Jay
- Thermal Ergonomics Laboratory, Faculty of Health Sciences, The University of Sydney, Lidcombe, NSW, AUSTRALIA.,Charles Perkins Centre, The University of Sydney, Camperdown, NSW, AUSTRALIA
| | - Scott L Davis
- Applied Physiology and Wellness, Southern Methodist University, Dallas, TX.,Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX
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23
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Wingo JE, Ng J, Katica CP, Carter SJ. Fan cooling after cardiovascular drift does not reverse decrements in maximal oxygen uptake during heat stress. Temperature (Austin) 2019; 6:260-270. [PMID: 31608305 DOI: 10.1080/23328940.2019.1657344] [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: 06/19/2019] [Revised: 08/14/2019] [Accepted: 08/14/2019] [Indexed: 01/07/2023] Open
Abstract
Cardiovascular (CV) drift, the progressive increase in heart rate (HR) and decrease in stroke volume (SV) during constant rate, moderate intensity exercise, is related to reduced maximal oxygen uptake (V̇O2max) during heat stress. Once it has already occurred, it is unknown whether the detrimental effects of CV drift on V̇O2max can be reversed. This study tested the hypothesis that fan cooling after CV drift has occurred attenuates decrements in V̇O2max associated with CV drift. Eight men completed a control graded exercise test (GXT) in 22°C to measure V̇O2max. Then on separate, counterbalanced occasions, they completed one 15-min (15MIN) and two 45-min bouts (45NF and 45FAN) of cycling in 35°C, 40% RH at 60% V̇O2max, each immediately followed by a GXT to measure V̇O2max. For one of the 45-min trials (45FAN), fan airflow (4.5 m/s) was directed at participants beginning ~5 min before the GXT and continuing throughout the remainder of exercise. The purpose of the separate 15- and 45-min trials was to measure V̇O2max during the same time interval that CV drift occurred. HR increased (13.8% and 11.4%) and SV decreased (14.4% and 14.1%) for 45NF and 45FAN, respectively; trials were not different (all P > 0.05). Despite a decrease in mean skin temperature of ~1°C with fan use, V̇O2max decreased similarly between conditions (17% vs. 15% for 45NF and 45FAN, P = 0.54). Fan cooling after CV drift was insufficient to reverse the negative consequences of CV drift on V̇O2max after prolonged exercise in a hot environment. Abbreviations: 15MIN: 15-min trial; 45FAN: 45-min, fan trial; 45NF: 45-min, no fan trial; ANOVA: Analysis of variance; CV: Cardiovascular; GXT: Graded exercise test; HR: Heart rate; SV: Stroke volume; T̅b: Mean body temperature; Tre: Rectal temperature; T̅sk: Mean skin temperature; V̇O2max: Maximal oxygen uptake.
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Affiliation(s)
- Jonathan E Wingo
- Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA
| | - Jason Ng
- Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA.,Department of Kinesiology, California State University, San Bernardino, CA, USA
| | - Charles P Katica
- Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA.,Department of Kinesiology, Pacific Lutheran University, Tacoma, WA, USA
| | - Stephen J Carter
- Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA.,Department of Kinesiology, Indiana University Bloomington, Bloomington, IN, USA
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24
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Ilett MJ, Rantalainen T, Keske MA, May AK, Warmington SA. The Effects of Restriction Pressures on the Acute Responses to Blood Flow Restriction Exercise. Front Physiol 2019; 10:1018. [PMID: 31456694 PMCID: PMC6700307 DOI: 10.3389/fphys.2019.01018] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 07/23/2019] [Indexed: 12/02/2022] Open
Abstract
Purpose No current guidelines or recommendations exist informing the selection of restriction pressure during blood flow restriction exercise (BFRE). Moreover, the effects of specific relative restriction pressures on the acute muscle, metabolic and cardiopulmonary responses to BFRE are unclear. The purpose of this study was to characterize these acute responses at different levels of restriction pressure. Methods Participants (n = 10) completed rhythmic isometric knee extension exercise across five experimental trials in a balanced randomized order. Three were BFRE trials {B-40 [restriction pressure set to 40% LOP (total limb occlusion pressure)]; B-60 (60% LOP); and B-80 (80% LOP)} with a workload equivalent to 20% maximal voluntary force (MVC), one was non-BFRE at 20% MVC (LL) and one was non-BFRE at 80% MVC (HL). Measurements recorded were torque, muscle activity via electromyography (EMG), tissue oxygenation via near infrared spectroscopy, whole body oxygen consumption, blood lactate and heart rate. Results For the LL and B-40 trials, most measures remained constant. However, for the B-60 and B-80 trials, significant fatigue was demonstrated by a reduction in MVC torque across the trial (p < 0.05). Blood lactate increased from baseline in HL, B-60, and B-80 (p < 0.05). Submaximal EMG was greater in B-60 and B-80 than LL, but lower compared with HL (p < 0.05). Tissue oxygenation decreased in HL, B-40, B-60, and B-80 (p < 0.05), which was lower in the B-80 trial compared to all other trials (p < 0.01). Whole body oxygen consumption was not different between the BFRE trials (p > 0.05). Conclusion We demonstrate graded/progressive acute responses with increasing applied pressure during BFRE, from which we speculate that an effective minimum “threshold” around 60% LOP may be necessary for BFRE to be effective with training. While these data provide some insight on the possible mechanisms by which BFRE develops skeletal muscle size and strength when undertaken chronically across a training program, the outcomes of chronic training programs using different levels of applied restriction pressures remain to be tested. Overall, the present study recommends 60–80% LOP as a suitable “minimum” BFRE pressure.
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Affiliation(s)
- Michael J Ilett
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition, Deakin University, Geelong, VIC, Australia
| | - Timo Rantalainen
- Gerontology Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Michelle A Keske
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition, Deakin University, Geelong, VIC, Australia
| | - Anthony K May
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition, Deakin University, Geelong, VIC, Australia
| | - Stuart A Warmington
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition, Deakin University, Geelong, VIC, Australia
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25
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Sharifi I, Goudarzi S, Khodabakhshi MB. A novel dynamical approach in continuous cuffless blood pressure estimation based on ECG and PPG signals. Artif Intell Med 2019; 97:143-151. [DOI: 10.1016/j.artmed.2018.12.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 12/17/2018] [Accepted: 12/18/2018] [Indexed: 12/01/2022]
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26
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Percutaneous transluminal angioplasty alone versus stent placement for the treatment of transplant renal artery stenosis. Diagn Interv Imaging 2019; 100:493-502. [PMID: 30952527 DOI: 10.1016/j.diii.2019.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 02/28/2019] [Accepted: 03/10/2019] [Indexed: 11/20/2022]
Abstract
PURPOSE The purposes of this retrospective study were to assess the efficacy of endovascular techniques for the treatment of transplant renal artery stenosis (TRAS) by analyzing technical and clinical success and to compare the results of percutaneous transluminal angioplasty (PTA) alone to those of stenting. MATERIALS AND METHODS A retrospective analysis was conducted on 31 patients who underwent endovascular treatment for TRAS between January 2012 and December 2017. There were 23 men and 8 women with a mean age of 60.5±14 (SD) years (range: 24-81 years). Ten patients (10/31; 32%; 8 men, 2 women; median age, 63 years) were treated with PTA alone and 21/31 (68%; 15 men, 6 women; median age, 65 years) with metallic stent placement. Several variables including serum creatinine level, glomerular filtration rate, arterial blood pressure value, antihypertensive medication obtained before and after treatment were compared. Technical success was assessed for each procedure. Clinical success was defined as a 15% drop in serum creatinine level, a decrease greater than 15% in mean blood pressure values or a decrease greater than 10% in mean blood pressure values with a reduction in the number of antihypertensive drugs needed for hypertension control. RESULTS Technical success was obtained in all patients [31/31; 100%; 95% confidence interval (CI): 89-100%] and clinical success in 27/31 patients (87%; 95%CI: 71-95%). Four patients (4/31; 13%; 95%CI: 5-29%) underwent repeat endovascular intervention. Mean serum creatinine level and mean arterial blood pressure values were significantly lower after treatment (177.4 and 93.8μmol/l, respectively) compared to before treatment (319.4 and 106.7μmol/l, respectively) in the stent group but not in the group treated with PTA alone (P=0.0012 and P=0.002, respectively). CONCLUSION The endovascular approach is safe and effective in the management of TRAS and stenting, depending on the morphology of the stenosis, should be the treatment of choice when possible.
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27
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Effects of exercise in normobaric hypoxia on hemodynamics during muscle metaboreflex activation in normoxia. Eur J Appl Physiol 2019; 119:1137-1148. [DOI: 10.1007/s00421-019-04103-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Accepted: 02/13/2019] [Indexed: 01/21/2023]
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28
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Roberto S, Milia R, Doneddu A, Pinna V, Palazzolo G, Serra S, Orrù A, Hosseini Kakhak SA, Ghiani G, Mulliri G, Pagliaro P, Crisafulli A. Hemodynamic abnormalities during muscle metaboreflex activation in patients with type 2 diabetes mellitus. J Appl Physiol (1985) 2018; 126:444-453. [PMID: 30543497 DOI: 10.1152/japplphysiol.00794.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Metaboreflex is a reflex triggered during exercise or postexercise muscle ischemia (PEMI) by metaboreceptor stimulation. Typical features of metaboreflex are increased cardiac output (CO) and blood pressure. Patients suffering from metabolic syndrome display hemodynamic abnormalities, with an exaggerated systemic vascular resistance (SVR) and reduced CO response during PEMI-induced metaboreflex. Whether patients with type 2 diabetes mellitus (DM2) have similar hemodynamic abnormalities is unknown. Here we contrast the hemodynamic response to PEMI in 14 patients suffering from DM2 (age 62.7 ± 8.3 yr) and in 15 age-matched controls (CTLs). All participants underwent a control exercise recovery reference test and a PEMI test to obtain the metaboreflex response. Central hemodynamics were evaluated by unbiased operator-independent impedance cardiography. Although the blood pressure response to PEMI was not significantly different between the groups, we found that the SVR and CO responses were reversed in patients with DM2 as compared with the CTLs (SVR: 392.5 ± 549.6 and -14.8 ± 258.9 dyn·s-1·cm-5; CO: -0.25 ± 0.63 and 0.46 ± 0.50 l/m, respectively, in DM2 and in CTL groups, respectively; P < 0.05 for both). Of note, stroke volume (SV) increased during PEMI in the CTL group only. Failure to increase SV and CO was the consequence of reduced venous return, impaired cardiac performance, and augmented afterload in patients with DM2. We conclude that patients with DM2 have an exaggerated vasoconstriction in response to metaboreflex activation not accompanied by a concomitant increase in heart performance. Therefore, in these patients, blood pressure response to the metaboreflex relies more on SVR increases rather than on increases in SV and CO. NEW & NOTEWORTHY The main new finding of the present investigation is that subjects with type 2 diabetes mellitus have an exaggerated vasoconstriction in response to metaboreflex activation. In these patients, blood pressure response to the metaboreflex relies more on systemic vascular resistance than on cardiac output increments.
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Affiliation(s)
- Silvana Roberto
- Sports Physiology Laboratory, Department of Medical Sciences and Public Health, University of Cagliari , Cagliari , Italy
| | - Raffaele Milia
- Sports Physiology Laboratory, Department of Medical Sciences and Public Health, University of Cagliari , Cagliari , Italy
| | - Azzurra Doneddu
- Sports Physiology Laboratory, Department of Medical Sciences and Public Health, University of Cagliari , Cagliari , Italy
| | - Virginia Pinna
- Sports Physiology Laboratory, Department of Medical Sciences and Public Health, University of Cagliari , Cagliari , Italy
| | - Girolamo Palazzolo
- Sports Physiology Laboratory, Department of Medical Sciences and Public Health, University of Cagliari , Cagliari , Italy
| | - Stefano Serra
- Sports Physiology Laboratory, Department of Medical Sciences and Public Health, University of Cagliari , Cagliari , Italy
| | - Andrea Orrù
- Sports Physiology Laboratory, Department of Medical Sciences and Public Health, University of Cagliari , Cagliari , Italy
| | | | - Giovanna Ghiani
- Sports Physiology Laboratory, Department of Medical Sciences and Public Health, University of Cagliari , Cagliari , Italy
| | - Gabriele Mulliri
- Sports Physiology Laboratory, Department of Medical Sciences and Public Health, University of Cagliari , Cagliari , Italy
| | - Pasquale Pagliaro
- Cardiovascular Physiology Laboratory, Department of Clinical and Biological Science, University of Torino , Turin , Italy
| | - Antonio Crisafulli
- Sports Physiology Laboratory, Department of Medical Sciences and Public Health, University of Cagliari , Cagliari , Italy
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29
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Crisafulli A, de Farias RR, Farinatti P, Lopes KG, Milia R, Sainas G, Pinna V, Palazzolo G, Doneddu A, Magnani S, Mulliri G, Roberto S, Oliveira RB. Blood Flow Restriction Training Reduces Blood Pressure During Exercise Without Affecting Metaboreflex Activity. Front Physiol 2018; 9:1736. [PMID: 30618781 PMCID: PMC6299290 DOI: 10.3389/fphys.2018.01736] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 11/16/2018] [Indexed: 12/12/2022] Open
Abstract
Objective: Blood flow restriction training (BFRT) has been proposed to induce muscle hypertrophy, but its safety remains controversial as it may increase mean arterial pressure (MAP) due to muscle metaboreflex activation. However, BFR training also causes metabolite accumulation that may desensitize type III and IV nerve endings, which trigger muscle metaboreflex. Then, we hypothesized that a period of BFR training would result in blunted hemodynamic activation during muscle metaboreflex. Methods: 17 young healthy males aged 18–25 yrs enrolled in this study. Hemodynamic responses during muscle metaboreflex were assessed by means of postexercise muscle ischemia (PEMI) at baseline (T0) and after 1 month (T1) of dynamic BFRT. BFRT consisted of 3-min rhythmic handgrip exercise applied 3 days/week (30 contractions per minute at 30% of maximum voluntary contraction) in the dominant arm. On the first week, the occlusion was set at 75% of resting systolic blood pressure (always obtained after 3 min of resting) and increased 25% every week, until reaching 150% of resting systolic pressure at week four. Hemodynamic measurements were assessed by means of impedance cardiography. Results: BFRT reduced MAP during handgrip exercise (T1: 96.3 ± 8.3 mmHg vs. T0: 102.0 ± 9.53 mmHg, p = 0.012). However, no significant time effect was detected for MAP during the metaboreflex activation (P > 0.05). Additionally, none of the observed hemodynamic outcomes, including systemic vascular resistance (SVR), showed significant difference between T0 and T1 during the metaboreflex activation (P > 0.05). Conclusion: BFRT reduced blood pressure during handgrip exercise, thereby suggesting a potential hypotensive effect of this modality of training. However, MAP reduction during handgrip seemed not to be provoked by lowered metaboreflex activity.
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Affiliation(s)
- Antonio Crisafulli
- Sports Physiology Laboratory, The Department of Medical Sciences and Public Health, and International PhD in Innovation Sciences and Technologies, University of Cagliari, Cagliari, Italy
| | - Rafael Riera de Farias
- Laboratory of Physical Activity and Health Promotion, University of Rio de Janeiro, Rio de Janeiro, Brazil.,Graduate Program in Exercise and Sport Sciences, University of Rio de Janeiro State, Rio de Janeiro, Brazil
| | - Paulo Farinatti
- Laboratory of Physical Activity and Health Promotion, University of Rio de Janeiro, Rio de Janeiro, Brazil.,Graduate Program in Exercise and Sport Sciences, University of Rio de Janeiro State, Rio de Janeiro, Brazil.,Graduate Program in Physical Activity Sciences, Salgado de Oliveira University, Niterói, Brazil
| | - Karynne Grutter Lopes
- Laboratory of Physical Activity and Health Promotion, University of Rio de Janeiro, Rio de Janeiro, Brazil.,Graduate Program in Clinical and Experimental Physiopathology, University of Rio de Janeiro State, Rio de Janeiro, Brazil.,Laboratory of Vascular Biology, University of Rio de Janeiro State, Rio de Janeiro, Brazil
| | - Raffaele Milia
- Sports Physiology Laboratory, The Department of Medical Sciences and Public Health, and International PhD in Innovation Sciences and Technologies, University of Cagliari, Cagliari, Italy
| | - Gianmarco Sainas
- Sports Physiology Laboratory, The Department of Medical Sciences and Public Health, and International PhD in Innovation Sciences and Technologies, University of Cagliari, Cagliari, Italy
| | - Virginia Pinna
- Sports Physiology Laboratory, The Department of Medical Sciences and Public Health, and International PhD in Innovation Sciences and Technologies, University of Cagliari, Cagliari, Italy
| | - Girolamo Palazzolo
- Sports Physiology Laboratory, The Department of Medical Sciences and Public Health, and International PhD in Innovation Sciences and Technologies, University of Cagliari, Cagliari, Italy
| | - Azzurra Doneddu
- Sports Physiology Laboratory, The Department of Medical Sciences and Public Health, and International PhD in Innovation Sciences and Technologies, University of Cagliari, Cagliari, Italy
| | - Sara Magnani
- Sports Physiology Laboratory, The Department of Medical Sciences and Public Health, and International PhD in Innovation Sciences and Technologies, University of Cagliari, Cagliari, Italy
| | - Gabriele Mulliri
- Sports Physiology Laboratory, The Department of Medical Sciences and Public Health, and International PhD in Innovation Sciences and Technologies, University of Cagliari, Cagliari, Italy
| | - Silvana Roberto
- Sports Physiology Laboratory, The Department of Medical Sciences and Public Health, and International PhD in Innovation Sciences and Technologies, University of Cagliari, Cagliari, Italy
| | - Ricardo Brandão Oliveira
- Graduate Program in Exercise and Sport Sciences, University of Rio de Janeiro State, Rio de Janeiro, Brazil.,Graduate Program in Clinical and Experimental Physiopathology, University of Rio de Janeiro State, Rio de Janeiro, Brazil.,Laboratory of Active Living (LaVA), University of Rio de Janeiro State, Rio de Janeiro, Brazil
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30
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O'Conor EC, Wang J, Gibney KD, Yu X, Young GR, Jones T, Alexandrov AW, Johnson KC, Cushman WC, Tsao JW. Lowering systolic blood pressure does not increase stroke risk: an analysis of the SPRINT and ACCORD trial data. Ann Clin Transl Neurol 2018; 6:144-153. [PMID: 30656192 PMCID: PMC6331200 DOI: 10.1002/acn3.693] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 10/16/2018] [Indexed: 11/12/2022] Open
Abstract
Objective Traditional neurology teaching states that when mean arterial pressure dips below a 60 mm Hg threshold, there is an increase in stroke risk due to cerebral hypoperfusion. The aim of this study was to determine whether intensive lowering of systolic blood pressure increases adverse cardiovascular outcomes by examining the association between achieved blood pressure values, specifically mean arterial pressure and pulse pressure, and risk of stroke. Methods Data from participants in the Systolic Blood Pressure Intervention Trial (SPRINT) and the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Blood Pressure (BP) trial were examined, using survival analysis to model minimal arterial pressure and average pulse pressure during the study period against risk of stroke, hypotension, and syncope, with death as a competing risk. Results In both SPRINT and ACCORD participants, there was no increase in stroke risk with achieved mean arterial pressure values below 60 mm Hg. In SPRINT participants, achieved mean arterial pressure values greater than 90 mm Hg were associated with a 247% (HR: 3.47, 95% CI: 2.06–5.85) higher risk of stroke compared with participants in the 80–89 mmHg reference group. No association was found between low achieved pulse pressure values and greater stroke risk in either the SPRINT or ACCORD participants, as well as no association between mean arterial pressure and pulse pressure values and risk of syncope. Interpretation Intensive lowering of systolic blood pressure does not increase risk of stroke in hypertensive patients, despite extremely low mean arterial pressure or pulse pressure values.
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Affiliation(s)
- Ellen C O'Conor
- Department of Neurology University of Tennessee Health Science Center Memphis Tennessee
| | - Jiajing Wang
- Department of Preventive Medicine College of Medicine University of Tennessee Health Science Center Memphis Tennessee
| | - Kyla D Gibney
- Department of Neurology University of Tennessee Health Science Center Memphis Tennessee
| | - Xinhua Yu
- Division of Epidemiology, Biostatistics, and Environmental Health School of Public Health University of Memphis Memphis Tennessee
| | - Garrett R Young
- Department of Neurology University of Tennessee Health Science Center Memphis Tennessee
| | - Tamekia Jones
- Department of Preventive Medicine College of Medicine University of Tennessee Health Science Center Memphis Tennessee.,Department of Pediatrics College of Medicine University of Tennessee Health Science Center Memphis Tennessee.,Children's Foundation Research Institute Le Bonheur Children's Hospital Memphis Tennessee
| | - Anne W Alexandrov
- College of Nursing University of Tennessee Health Science Center Memphis Tennessee
| | - Karen C Johnson
- Department of Preventive Medicine College of Medicine University of Tennessee Health Science Center Memphis Tennessee
| | - William C Cushman
- Department of Preventive Medicine College of Medicine University of Tennessee Health Science Center Memphis Tennessee.,Memphis Veterans Affairs Medical Center Memphis Tennessee
| | - Jack W Tsao
- Department of Neurology University of Tennessee Health Science Center Memphis Tennessee.,Department of Pediatrics College of Medicine University of Tennessee Health Science Center Memphis Tennessee.,Children's Foundation Research Institute Le Bonheur Children's Hospital Memphis Tennessee.,Memphis Veterans Affairs Medical Center Memphis Tennessee
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Huang M, Brothers RM, Ganio MS, Lucas RAI, Cramer MN, Moralez G, Convertino VA, Crandall CG. Tolerance to a haemorrhagic challenge during heat stress is improved with inspiratory resistance breathing. Exp Physiol 2018; 103:1243-1250. [PMID: 29947436 PMCID: PMC6119106 DOI: 10.1113/ep087102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/22/2018] [Indexed: 02/06/2023]
Abstract
NEW FINDINGS What is the central question of this study? Does inspiratory resistance breathing improve tolerance to simulated haemorrhage in individuals with elevated internal temperatures? What is the main finding and its importance? The main finding of this study is that inspiratory resistance breathing modestly improves tolerance to a simulated progressive haemorrhagic challenge during heat stress. These findings demonstrate a scenario in which exploitation of the respiratory pump can ameliorate serious conditions related to systemic hypotension. ABSTRACT Heat exposure impairs human blood pressure control and markedly reduces tolerance to a simulated haemorrhagic challenge. Inspiratory resistance breathing enhances blood pressure control and improves tolerance during simulated haemorrhage in normothermic individuals. However, it is unknown whether similar improvements occur with this manoeuvre in heat stress conditions. In this study, we tested the hypothesis that inspiratory resistance breathing improves tolerance to simulated haemorrhage in individuals with elevated internal temperatures. On two separate days, eight subjects performed a simulated haemorrhage challenge [lower-body negative pressure (LBNP)] to presyncope after an increase in internal temperature of 1.3 ± 0.1°C. During one trial, subjects breathed through an inspiratory impedance device set at 0 cmH2 O of resistance (Sham), whereas on a subsequent day the device was set at -7 cmH2 O of resistance (ITD). Tolerance was quantified as the cumulative stress index. Subjects were more tolerant to the LBNP challenge during the ITD protocol, as indicated by a > 30% larger cumulative stress index (Sham, 520 ± 306 mmHg min; ITD, 682 ± 324 mmHg min; P < 0.01). These data indicate that inspiratory resistance breathing modestly improves tolerance to a simulated progressive haemorrhagic challenge during heat stress.
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Affiliation(s)
- Mu Huang
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, USA
- Department of Health Care Sciences, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - R Matthew Brothers
- Department of Kinesiology, University of Texas, Arlington, Arlington, TX, USA
| | - Matthew S Ganio
- Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR, USA
| | - Rebekah A I Lucas
- School of Sport, Exercise & Rehabilitation Sciences, The University of Birmingham, Edgbaston, Birmingham, UK
| | - Matthew N Cramer
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, USA
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Gilbert Moralez
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, USA
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Craig G Crandall
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, USA
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Rossetti GMK, Macdonald JH, Wylie LJ, Little SJ, Newton V, Wood B, Hawkins KA, Beddoe R, Davies HE, Oliver SJ. Dietary nitrate supplementation increases acute mountain sickness severity and sense of effort during hypoxic exercise. J Appl Physiol (1985) 2017; 123:983-992. [DOI: 10.1152/japplphysiol.00293.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/28/2017] [Accepted: 07/01/2017] [Indexed: 12/12/2022] Open
Abstract
Dietary nitrate supplementation enhances sea level performance and may ameliorate hypoxemia at high altitude. However, nitrate may exacerbate acute mountain sickness (AMS), specifically headache. This study investigated the effect of nitrate supplementation on AMS symptoms and exercise responses with 6-h hypoxia. Twenty recreationally active men [age, 22 ± 4 yr, maximal oxygen consumption (V̇o2max), 51 ± 6 ml·min−1·kg−1, means ± SD] completed this randomized double-blinded placebo-controlled crossover study. Twelve participants were classified as AMS− on the basis of Environmental Symptoms Questionnaire [Acute Cerebral Mountain Sickness score (AMS-C)] <0.7 in both trials, and five participants were classified as AMS+ on the basis of AMS-C ≥0.7 on placebo. Five days of nitrate supplementation (70-ml beetroot juice containing ~6.4 mmol nitrate daily) increased plasma NO metabolites by 182 µM compared with placebo but did not reduce AMS or improve exercise performance. After 4-h hypoxia [inspired O2 fraction ([Formula: see text]) = 0.124], nitrate increased AMS-C and headache severity (visual analog scale; whole sample ∆10 [1, 20] mm, mean difference [95% confidence interval]; P = 0.03) compared with placebo. In addition, after 5-h hypoxia, nitrate increased sense of effort during submaximal exercise (∆7 [−1, 14]; P = 0.07). In AMS−, nitrate did not alter headache or sense of effort. In contrast, in AMS+, nitrate increased headache severity (∆26 [−3, 56] mm; P = 0.07), sense of effort (∆14 [1, 28]; P = 0.04), oxygen consumption, ventilation, and mean arterial pressure during submaximal exercise. On the next day, in a separate acute hypoxic exercise test ([Formula: see text] = 0.141), nitrate did not improve time to exhaustion at 80% hypoxic V̇o2max. In conclusion, dietary nitrate increases AMS and sense of effort during exercise, particularly in those who experience AMS. Dietary nitrate is therefore not recommended as an AMS prophylactic or ergogenic aid in nonacclimatized individuals at altitude. NEW & NOTEWORTHY This is the first study to identify that the popular dietary nitrate supplement (beetroot) does not reduce acute mountain sickness (AMS) or improve exercise performance during 6-h hypoxia. The consumption of nitrate in those susceptible to AMS exacerbates AMS symptoms (headache) and sense of effort and raises oxygen cost, ventilation, and blood pressure during walking exercise in 6-h hypoxia. These data question the suitability of nitrate supplementation during altitude travel in nonacclimatized people.
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Affiliation(s)
- Gabriella M. K. Rossetti
- Extremes Research Group, College of Health and Behavioural Sciences, Bangor University, Bangor, United Kingdom; and
| | - Jamie H. Macdonald
- Extremes Research Group, College of Health and Behavioural Sciences, Bangor University, Bangor, United Kingdom; and
| | - Lee J. Wylie
- Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, St. Luke’s Campus, Exeter, United Kingdom
| | - Samuel J. Little
- Extremes Research Group, College of Health and Behavioural Sciences, Bangor University, Bangor, United Kingdom; and
| | - Victoria Newton
- Extremes Research Group, College of Health and Behavioural Sciences, Bangor University, Bangor, United Kingdom; and
| | - Benjamin Wood
- Extremes Research Group, College of Health and Behavioural Sciences, Bangor University, Bangor, United Kingdom; and
| | - Kieran A. Hawkins
- Extremes Research Group, College of Health and Behavioural Sciences, Bangor University, Bangor, United Kingdom; and
| | - Rhys Beddoe
- Extremes Research Group, College of Health and Behavioural Sciences, Bangor University, Bangor, United Kingdom; and
| | - Hannah E. Davies
- Extremes Research Group, College of Health and Behavioural Sciences, Bangor University, Bangor, United Kingdom; and
| | - Samuel J. Oliver
- Extremes Research Group, College of Health and Behavioural Sciences, Bangor University, Bangor, United Kingdom; and
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Allen DR, Huang M, Parupia IM, Dubelko AR, Frohman EM, Davis SL. Impaired sweating responses to a passive whole body heat stress in individuals with multiple sclerosis. J Neurophysiol 2017; 118:7-14. [PMID: 28275061 DOI: 10.1152/jn.00897.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 03/02/2017] [Accepted: 03/07/2017] [Indexed: 01/11/2023] Open
Abstract
Multiple sclerosis (MS) is an autoimmune disease that affects the central nervous system (CNS), disrupting autonomic function. The aim of this study was to test the hypothesis that individuals with MS have blunted control of thermoregulatory reflex increases in sweat rate (SR) and cutaneous vasodilation compared with controls during a passive whole body heat stress (WBH). Eighteen individuals with relapsing-remitting MS and 18 healthy controls (Con) participated in the study. Core temperature (Tcore), skin temperature, heart rate, arterial blood pressure (10-min intervals), skin blood flow (laser-Doppler flux, LDF), and SR were continuously measured during normothermic baseline (34°C water perfusing a tube-lined suit) and WBH (increased Tcore 0.8°C via 48°C water perfusing the suit). Following WBH, local heaters were warmed to 42°C, inducing peak cutaneous vasodilation at the site of LDF collection. Cutaneous vascular conductance (CVC) was calculated as the ratio of LDF to mean arterial pressure and expressed as a percentage of peak achieved during local heating. Individuals with MS had attenuated SR responses to WBH (ΔSR from baseline: Con, 0.65 ± 0.27; MS, 0.42 ± 0.17 mg·cm-2·min-1, P = 0.003), whereas Δ%CVC42C from baseline was similar between groups (Con, 42 ± 16%; MS, 38 ± 12%, P = 0.39). SR responses were blunted as a function of Tcore in MS (interaction: group × Tcore, P = 0.03), of which differences were evident at ΔTcore 0.7°C and 0.8°C (P < 0.05). No interaction was observed in Δ%CVC42C Taken together, the findings show MS blunts sweating responses, whereas control of the cutaneous vasculature is preserved, in response to WBH.NEW & NOTEWORTHY This study is the first to assess the reflex control of the thermoregulatory system in individuals living with multiple sclerosis (MS). The novel findings are twofold. First, attenuated increases in sweat rate in subjects with MS compared with healthy controls were observed in response to a moderate increase (0.8°C) in core temperature via passive whole body heat stress. Second, it appears the reflex control of the cutaneous vasculature is preserved in MS.
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Affiliation(s)
- Dustin R Allen
- Department of Applied Physiology & Wellness, Southern Methodist University, Dallas, Texas; and
| | - Mu Huang
- Department of Applied Physiology & Wellness, Southern Methodist University, Dallas, Texas; and
| | - Iqra M Parupia
- Department of Applied Physiology & Wellness, Southern Methodist University, Dallas, Texas; and
| | - Ariana R Dubelko
- Department of Applied Physiology & Wellness, Southern Methodist University, Dallas, Texas; and
| | - Elliot M Frohman
- Department of Neurology & Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Scott L Davis
- Department of Applied Physiology & Wellness, Southern Methodist University, Dallas, Texas; and .,Department of Neurology & Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas
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Thazhath SS, Marathe CS, Wu T, Chang J, Khoo J, Kuo P, Checklin HL, Bound MJ, Rigda RS, Horowitz M, Jones KL, Rayner CK. Acute effects of the glucagon-like peptide-1 receptor agonist, exenatide, on blood pressure and heart rate responses to intraduodenal glucose infusion in type 2 diabetes. Diab Vasc Dis Res 2017; 14:59-63. [PMID: 27941058 DOI: 10.1177/1479164116666761] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
AIM To evaluate the effects of the glucagon-like peptide-1 receptor agonist, exenatide, on blood pressure and heart rate during an intraduodenal glucose infusion in type 2 diabetes. METHODS Nine subjects with type 2 diabetes were randomised to receive intravenous exenatide or saline control in a crossover design. Glucose (3 kcal min-1) was infused via an intraduodenal manometry catheter for 60 min. Blood pressure, heart rate, and the frequency and amplitude of duodenal pressure waves were measured at regular intervals. Gastrointestinal symptoms were monitored using 100 mm visual analogue scales. RESULTS During intraduodenal glucose infusion (0-60 min), diastolic (p(0-60) = 0.03) and mean arterial (p(0-60) = 0.03) blood pressures and heart rate (p(0-60) = 0.06; p(0-120) = 0.03)) were higher with exenatide compared to placebo. The increase in the area under the curve for diastolic blood pressure and mean arterial blood pressure was related directly to the suppression of the duodenal motility index with exenatide compared to control (p = 0.007 and 0.04, respectively). CONCLUSION In type 2 diabetes, intravenous exenatide increases mean arterial blood pressure and heart rate during an intraduodenal glucose infusion, supporting the need for further research with exenatide for its potential use in postprandial hypotension.
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Affiliation(s)
- Sony S Thazhath
- Discipline of Medicine, Royal Adelaide Hospital, The University of Adelaide, Adelaide, SA, Australia
- Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, Australia
| | - Chinmay S Marathe
- Discipline of Medicine, Royal Adelaide Hospital, The University of Adelaide, Adelaide, SA, Australia
- Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, Australia
| | - Tongzhi Wu
- Discipline of Medicine, Royal Adelaide Hospital, The University of Adelaide, Adelaide, SA, Australia
- Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, Australia
| | - Jessica Chang
- Discipline of Medicine, Royal Adelaide Hospital, The University of Adelaide, Adelaide, SA, Australia
- Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, Australia
| | - Joan Khoo
- Discipline of Medicine, Royal Adelaide Hospital, The University of Adelaide, Adelaide, SA, Australia
- Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, Australia
- Department of Endocrinology, Changi General Hospital, Singapore
| | - Paul Kuo
- Discipline of Medicine, Royal Adelaide Hospital, The University of Adelaide, Adelaide, SA, Australia
- Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, Australia
| | - Helen L Checklin
- Discipline of Medicine, Royal Adelaide Hospital, The University of Adelaide, Adelaide, SA, Australia
- Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, Australia
| | - Michelle J Bound
- Discipline of Medicine, Royal Adelaide Hospital, The University of Adelaide, Adelaide, SA, Australia
- Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, Australia
| | - Rachael S Rigda
- Discipline of Medicine, Royal Adelaide Hospital, The University of Adelaide, Adelaide, SA, Australia
- Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, Australia
| | - Michael Horowitz
- Discipline of Medicine, Royal Adelaide Hospital, The University of Adelaide, Adelaide, SA, Australia
- Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, Australia
| | - Karen L Jones
- Discipline of Medicine, Royal Adelaide Hospital, The University of Adelaide, Adelaide, SA, Australia
- Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, Australia
| | - Christopher K Rayner
- Discipline of Medicine, Royal Adelaide Hospital, The University of Adelaide, Adelaide, SA, Australia
- Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, Australia
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Roberto S, Mulliri G, Milia R, Solinas R, Pinna V, Sainas G, Piepoli MF, Crisafulli A. Hemodynamic response to muscle reflex is abnormal in patients with heart failure with preserved ejection fraction. J Appl Physiol (1985) 2016; 122:376-385. [PMID: 27979984 DOI: 10.1152/japplphysiol.00645.2016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 11/22/2016] [Accepted: 12/12/2016] [Indexed: 11/22/2022] Open
Abstract
The aim of the present investigation was to assess the role of cardiac diastole on the hemodynamic response to metaboreflex activation. We wanted to determine whether patients with diastolic function impairment showed a different hemodynamic response compared with normal subjects during this reflex. Hemodynamics during activation of the metaboreflex obtained by postexercise muscle ischemia (PEMI) was assessed in 10 patients with diagnosed heart failure with preserved ejection fraction (HFpEF) and in 12 age-matched healthy controls (CTL). Subjects also performed a control exercise-recovery test to compare data from the PEMI test. The main results were that patients with HFpEF achieved a similar mean arterial blood pressure (MAP) response as the CTL group during the PEMI test. However, the mechanism by which this response was achieved was markedly different between the two groups. Patients with HFpEF achieved the target MAP via an increase in systemic vascular resistance (+389.5 ± 402.9 vs. +80 ± 201.9 dynes·s-1·cm-5 for HFpEF and CTL groups respectively), whereas MAP response in the CTL group was the result of an increase in cardiac preload (-1.3 ± 5.2 vs. 6.1 ± 10 ml in end-diastolic volume for HFpEF and CTL groups, respectively), which led to a rise in stroke volume and cardiac output. Moreover, early filling peak velocities showed a higher response in the CTL group than in the HFpEF group. This study demonstrates that diastolic function is important for normal hemodynamic adjustment to the metaboreflex. Moreover, it provides evidence that HFpEF causes hemodynamic impairment similar to that observed in systolic heart failure.NEW & NOTEWORTHY This study provides evidence that diastolic function is important for normal hemodynamic responses during the activation of the muscle metaboreflex in humans. Moreover, it demonstrates that diastolic impairment leads to hemodynamic consequences similar to those provoked by systolic heart failure. In both cases the target blood pressure is obtained mainly by means of exaggerated vasoconstriction than by a flow-mediated mechanism.
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Affiliation(s)
- Silvana Roberto
- Department of Medical Sciences, Sports Physiology Lab., University of Cagliari, Cagliari, Italy; and
| | - Gabriele Mulliri
- Department of Medical Sciences, Sports Physiology Lab., University of Cagliari, Cagliari, Italy; and
| | - Raffaele Milia
- Department of Medical Sciences, Sports Physiology Lab., University of Cagliari, Cagliari, Italy; and
| | - Roberto Solinas
- Department of Medical Sciences, Sports Physiology Lab., University of Cagliari, Cagliari, Italy; and
| | - Virginia Pinna
- Department of Medical Sciences, Sports Physiology Lab., University of Cagliari, Cagliari, Italy; and
| | - Gianmarco Sainas
- Department of Medical Sciences, Sports Physiology Lab., University of Cagliari, Cagliari, Italy; and
| | | | - Antonio Crisafulli
- Department of Medical Sciences, Sports Physiology Lab., University of Cagliari, Cagliari, Italy; and
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Magnani S, Olla S, Pau M, Palazzolo G, Tocco F, Doneddu A, Marcelli M, Loi A, Corona F, Corona F, Coghe G, Marrosu MG, Concu A, Cocco E, Marongiu E, Crisafulli A. Effects of Six Months Training on Physical Capacity and Metaboreflex Activity in Patients with Multiple Sclerosis. Front Physiol 2016; 7:531. [PMID: 27895592 PMCID: PMC5108173 DOI: 10.3389/fphys.2016.00531] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 10/25/2016] [Indexed: 12/20/2022] Open
Abstract
Patients with multiple sclerosis (MS) have an increased systemic vascular resistance (SVR) response during the metaboreflex. It has been hypothesized that this is the consequence of a sedentary lifestyle secondary to MS. The purpose of this study was to discover whether a 6-month training program could reverse this hemodynamic dysregulation. Patients were randomly assigned to one of the following two groups: the intervention group (MSIT, n = 11), who followed an adapted training program; and the control group (MSCTL, n = 10), who continued with their sedentary lifestyle. Cardiovascular response during the metaboreflex was evaluated using the post-exercise muscle ischemia (PEMI) method and during a control exercise recovery (CER) test. The difference in hemodynamic variables such as stroke volume (SV), cardiac output (CO), and SVR between the PEMI and the CER tests was calculated to assess the metaboreflex response. Moreover, physical capacity was measured during a cardiopulmonary test till exhaustion. All tests were repeated after 3 and 6 months (T3 and T6, respectively) from the beginning of the study. The main result was that the MSIT group substantially improved parameters related to physical capacity (+5.31 ± 5.12 ml·min−1/kg in maximal oxygen uptake at T6) in comparison with the MSCTL group (−0.97 ± 4.89 ml·min−1/kg at T6; group effect: p = 0.0004). However, none of the hemodynamic variables changed in response to the metaboreflex activation. It was concluded that a 6-month period of adapted physical training was unable to reverse the hemodynamic dys-regulation in response to metaboreflex activation in these patients.
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Affiliation(s)
- Sara Magnani
- Sports Physiology Lab, Department of Medical Sciences, University of Cagliari Cagliari, Italy
| | - Sergio Olla
- Sports Physiology Lab, Department of Medical Sciences, University of Cagliari Cagliari, Italy
| | - Massimiliano Pau
- Department of Mechanical, Chemical and Materials Engineering, University of Cagliari Cagliari, Italy
| | - Girolamo Palazzolo
- Sports Physiology Lab, Department of Medical Sciences, University of Cagliari Cagliari, Italy
| | - Filippo Tocco
- Sports Physiology Lab, Department of Medical Sciences, University of Cagliari Cagliari, Italy
| | - Azzurra Doneddu
- Sports Physiology Lab, Department of Medical Sciences, University of Cagliari Cagliari, Italy
| | - Maura Marcelli
- Sports Physiology Lab, Department of Medical Sciences, University of Cagliari Cagliari, Italy
| | - Andrea Loi
- Sports Physiology Lab, Department of Medical Sciences, University of Cagliari Cagliari, Italy
| | - Federica Corona
- Department of Mechanical, Chemical and Materials Engineering, University of CagliariCagliari, Italy; Department of Public Health, Clinical and Molecular Medicine, University of CagliariCagliari, Italy
| | - Francesco Corona
- Sports Physiology Lab, Department of Medical Sciences, University of Cagliari Cagliari, Italy
| | - Giancarlo Coghe
- Department of Mechanical, Chemical and Materials Engineering, University of Cagliari Cagliari, Italy
| | - Maria G Marrosu
- Sports Physiology Lab, Department of Medical Sciences, University of Cagliari Cagliari, Italy
| | - Alberto Concu
- Sports Physiology Lab, Department of Medical Sciences, University of Cagliari Cagliari, Italy
| | - Eleonora Cocco
- Department of Mechanical, Chemical and Materials Engineering, University of Cagliari Cagliari, Italy
| | - Elisabetta Marongiu
- Sports Physiology Lab, Department of Medical Sciences, University of Cagliari Cagliari, Italy
| | - Antonio Crisafulli
- Sports Physiology Lab, Department of Medical Sciences, University of Cagliari Cagliari, Italy
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Krnjajic D, Allen DR, Butts CL, Keller DM. Carotid baroreflex control of heart rate is enhanced, while control of mean arterial pressure is preserved during whole body heat stress in young healthy men. Am J Physiol Regul Integr Comp Physiol 2016; 311:R735-R741. [DOI: 10.1152/ajpregu.00152.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/29/2016] [Indexed: 11/22/2022]
Abstract
Whole body heat stress (WBH) results in numerous cardiovascular alterations that ultimately reduce orthostatic tolerance. While impaired carotid baroreflex (CBR) function during WBH has been reported as a potential reason for this decrement, study design considerations may limit interpretation of previous findings. We sought to test the hypothesis that CBR function is unaltered during WBH. CBR function was assessed in 10 healthy male subjects (age: 26 ± 3; height: 185 ± 7 cm; weight: 82 ± 10 kg; BMI: 24 ± 3 kg/m2; means ± SD) using 5-s trials of neck pressure (+45, +30, and +15 Torr) and neck suction (−20, −40, −60, and −80 Torr) during normothermia (NT) and passive WBH (Δ core temp ∼1°C). Analyses of stimulus response curves (four-parameter logistic model) for CBR control of heart rate (CBR-HR) and mean arterial pressure (CBR-MAP), as well as separate two-way ANOVA of the hypotensive and hypertensive stimuli (factor 1: thermal condition, factor 2: chamber pressure), were performed. For CBR-HR, maximal gain was increased during WBH (−0.73 ± 0.11) compared with NT (−0.39 ± 0.04, mean ± SE, P = 0.03). In addition, the CBR-HR responding range was increased during WBH (33 ± 5) compared with NT (19 ± 2 bpm, P = 0.03). Separate analysis of hypertensive stimulation revealed enhanced HR responses during WBH at −40, −60, and −80 Torr (condition × chamber pressure interaction, P = 0.049) compared with NT. For CBR-MAP, both logistic analysis and separate two-way ANOVA revealed no differences during WBH. Therefore, in response to passive WBH, CBR control of heart rate (enhanced) and arterial pressure (no change) is well preserved.
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Affiliation(s)
- Davor Krnjajic
- Department of Kinesiology, University of Texas, Arlington, Arlington, Texas
| | - Dustin R. Allen
- Department of Kinesiology, University of Texas, Arlington, Arlington, Texas
| | - Cory L. Butts
- Department of Kinesiology, University of Texas, Arlington, Arlington, Texas
| | - David M. Keller
- Department of Kinesiology, University of Texas, Arlington, Arlington, Texas
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Ejim E, Oguanobi N. Left ventricular systolic function in sickle cell anaemia: an echocardiographic evaluation in adult Nigerian patients. Afr Health Sci 2016; 16:755-765. [PMID: 27917209 DOI: 10.4314/ahs.v16i3.16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Reliable diagnostic measures for the evaluation of left ventricular systolic performance in the setting of altered myocardial loading characteristics in sickle cell anaemia remains unresolved. OBJECTIVE The study was designed to assess left ventricular systolic function in adult sickle cell patients using non-invasive endsystolic stress - end-systolic volume index ratio. METHODS A descriptive cross sectional comparative study was done using 52 patients recruited at the adult sickle cell anaemia clinic of the University of Nigeria Teaching Hospital Enugu. An equal number of age and sex-matched healthy volunteers served as controls. All the participants had haematocrit estimation, haemoglobin electrophoresis, as well as echocardiographic evaluation. RESULT The mean age of the patients and controls were 23.93 ± 5.28 (range 18-42) and 24.17 ± 4.39 (range 19 -42) years respectively, (t = 0.262; p= .794). No significant difference was seen in estimate of fractional shortening, and ejection fraction. The cardiac out-put, cardiac index and velocity of circumferential shortening were all significantly increased in the cases compared with the controls. The end systolic stress - end systolic volume index ratio (ESS/ESVI) was significantly lower in cases than controls. There were strong positive correlation between the ejection phase indices (ejection fraction and fractional shortening) and end systolic stress and ESS/ESVI. CONCLUSION The study findings suggest the presence of left ventricular systolic dysfunction in adult sickle cell anaemia. This is best detected using the loading-pressures independent force-length relationship expressed in ESS/ESVI ratio.
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Affiliation(s)
- Emmanuel Ejim
- University of Nigeria Teaching Hospital, Enugu, Medicine
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Mulliri G, Sainas G, Magnani S, Palazzolo G, Milia N, Orrù A, Roberto S, Marongiu E, Milia R, Crisafulli A. Ischemic preconditioning reduces hemodynamic response during metaboreflex activation. Am J Physiol Regul Integr Comp Physiol 2016; 310:R777-87. [PMID: 26936782 DOI: 10.1152/ajpregu.00429.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 03/01/2016] [Indexed: 11/22/2022]
Abstract
Ischemic preconditioning (IP) has been shown to improve exercise performance and to delay fatigue. However, the precise mechanisms through which IP operates remain elusive. It has been hypothesized that IP lowers the sensation of fatigue by reducing the discharge of group III and IV nerve endings, which also regulate hemodynamics during the metaboreflex. We hypothesized that IP reduces the blood pressure response during the metaboreflex. Fourteen healthy males (age between 25 and 48 yr) participated in this study. They underwent the following randomly assigned protocol: postexercise muscle ischemia (PEMI) test, during which the metaboreflex was elicited after dynamic handgrip; control exercise recovery session (CER) test; and PEMI after IP (IP-PEMI) test. IP was obtained by occluding forearm circulation for three cycles of 5 min spaced by 5 min of reperfusion. Hemodynamics were evaluated by echocardiography and impedance cardiography. The main results were that after IP the mean arterial pressure response was reduced compared with the PEMI test (means ± SD +3.37 ± 6.41 vs. +9.16 ± 7.09 mmHg, respectively). This was the consequence of an impaired venous return that impaired the stroke volume during the IP-PEMI more than during the PEMI test (-1.43 ± 15.35 vs. +10.28 ± 10.479 ml, respectively). It was concluded that during the metaboreflex, IP affects hemodynamics mainly because it impairs the capacity to augment venous return and to recruit the cardiac preload reserve. It was hypothesized that this is the consequence of an increased nitric oxide production, which reduces the possibility to constrict venous capacity vessels.
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Affiliation(s)
- Gabriele Mulliri
- Department of Medical Sciences, Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy
| | - Gianmarco Sainas
- Department of Medical Sciences, Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy
| | - Sara Magnani
- Department of Medical Sciences, Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy
| | - Girolamo Palazzolo
- Department of Medical Sciences, Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy
| | - Nicola Milia
- Department of Medical Sciences, Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy
| | - Andrea Orrù
- Department of Medical Sciences, Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy
| | - Silvana Roberto
- Department of Medical Sciences, Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy
| | - Elisabetta Marongiu
- Department of Medical Sciences, Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy
| | - Raffaele Milia
- Department of Medical Sciences, Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy
| | - Antonio Crisafulli
- Department of Medical Sciences, Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy
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Effects of mild hypohydration on cooling during cold-water immersion following exertional hyperthermia. Eur J Appl Physiol 2016; 116:687-95. [DOI: 10.1007/s00421-016-3329-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/05/2016] [Indexed: 10/22/2022]
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Zhu G, Yuan Q, Yang J, Yeo JH. The role of the circle of Willis in internal carotid artery stenosis and anatomical variations: a computational study based on a patient-specific three-dimensional model. Biomed Eng Online 2015; 14:107. [PMID: 26608827 PMCID: PMC4659208 DOI: 10.1186/s12938-015-0105-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 11/18/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of this study is to provide better insights into the cerebral perfusion patterns and collateral mechanism of the circle of Willis (CoW) under anatomical and pathological variations. METHODS In the current study, a patient-specific three-dimensional computational model of the CoW was reconstructed based on the computed tomography (CT) images. The Carreau model was applied to simulate the non-Newtonian property of blood. Flow distributions in five common anatomical variations coexisting with different degrees of stenosis in the right internal carotid artery (RICA) were investigated to obtain detailed flow information. RESULTS With the development of stenosis in unilateral internal carotid artery (ICA), the cerebral blood supply decreased when the degree of stenosis increased. The blood supply of the ipsilateral middle cerebral artery (MCA) was most affected by the stenosis of ICA. The anterior communicating artery (ACoA) and ipsilateral posterior communicating artery (PCoA) functioned as the important collateral circulation channels when unilateral stenosis occurred. The blood flow of the anterior circulation and the total cerebral blood flow (CBF) reached to the minimum in the configuration of the contralateral proximal anterior cerebral artery (A1) absence coexisting with unilateral ICA stenosis. CONCLUSIONS Communicating arteries provided important collateral channels in the complete CoW when stenosis in unilateral ICA occurred. The cross-flow in the ACoA is a sensitive indicator of the morphological change of the ICA. The collateral function of the PCoA on the affected side will not be fully activated until a severe stenosis occurred in unilateral ICA. The absence of unilateral A1 coexisting with the stenosis in the contralateral ICA could be the most dangerous configuration in terms of the total cerebral blood supply. The findings of this study would enhance the understanding of the collateral mechanism of the CoW under different anatomical variations.
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Affiliation(s)
- Guangyu Zhu
- School of Energy and Power Engineering, Xi'an Jiaotong University, 28 Xian Ning West Rd, Xi'an, 710049, Shaanxi, China.
| | - Qi Yuan
- School of Energy and Power Engineering, Xi'an Jiaotong University, 28 Xian Ning West Rd, Xi'an, 710049, Shaanxi, China.
| | - Jian Yang
- Department of Radiology and Medical Imaging, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, Shaanxi, China.
| | - Joon Hock Yeo
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Ave, Singapore, 639798, Singapore.
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Metaboreflex activity in multiple sclerosis patients. Eur J Appl Physiol 2015; 115:2481-90. [PMID: 26429722 DOI: 10.1007/s00421-015-3271-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 09/22/2015] [Indexed: 10/23/2022]
Abstract
PURPOSE The muscle metaboreflex activation has been shown essential to reach normal hemodynamic response during exercise. It has been demonstrated that patients with multiple sclerosis (MS) have impaired autonomic functions and cardiovascular regulation during exercise. However, to the best of our knowledge, no previous research to date has studied the metaboreflex in MS patients. The purpose of this study was to investigate the hemodynamic response to metaboreflex activation in patients with MS (n = 43) compared to an age-matched, control group (CTL, n = 21). METHODS Cardiovascular response during the metaboreflex was evaluated using the post-exercise muscle ischemia (PEMI) method and during a control exercise recovery (CER) test. The difference in hemodynamics between the PEMI and the CER test was calculated and this procedure allowed for the assessment of the metaboreflex response. Hemodynamics was estimated by impedance cardiography. RESULTS The MS group showed a normal mean blood pressure (MBP) response as compared to the CTL group (+6.5 ± 6.9 vs. +8 ± 6.8 mmHg, respectively), but this response was achieved with an increase in systemic vascular resistance, that was higher in the MS with respect to the CTL group (+137.6 ± 300.5 vs. -14.3 ± 240 dyne · s(-1) cm(-5), respectively). This was the main consequence of the MS group's incapacity to raise the stroke volume (-0.65 ± 10.6 vs. +6.2 ± 12.8 ml, respectively). CONCLUSION It was concluded that MS patients have an impaired capacity to increase stroke volume (SV) in response to low level metaboreflex, even if they could sustain the MBP response by vasoconstriction. This was probably a consequence of their chronic physical de-conditioning.
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Milia R, Velluzzi F, Roberto S, Palazzolo G, Sanna I, Sainas G, Pusceddu M, Mulliri G, Loviselli A, Crisafulli A. Differences in hemodynamic response to metaboreflex activation between obese patients with metabolic syndrome and healthy subjects with obese phenotype. Am J Physiol Heart Circ Physiol 2015; 309:H779-89. [DOI: 10.1152/ajpheart.00250.2015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 06/30/2015] [Indexed: 01/07/2023]
Abstract
Patients suffering from obesity and metabolic syndrome (OMS) manifest a dysregulation in hemodynamic response during exercise, with an exaggerated systemic vascular increase. However, it is not clear whether this is the consequence of metabolic syndrome per se or whether it is due to concomitant obesity. The aim of the present investigation was to discover whether OMS and noncomplicated obesity resulted in different hemodynamic responses during the metaboreflex. Twelve metabolically healthy but obese subjects (MHO; 7 women), 13 OMS patients (5 women), and 12 normal age-matched controls (CTL; 6 women) took part in this study. All participants underwent a postexercise muscle ischemia protocol to evaluate the metaboreflex activity. Central hemodynamics were evaluated by impedance cardiography. The main result shows an exaggerated increase in systemic vascular resistance from baseline during the metaboreflex in the OMS patients as compared with the other groups (481.6 ± 180.3, −0.52 ± 177.6, and −60.5 ± 58.6 dynes·s−1·cm−5 for the OMS, the MHO, and the CTL groups, respectively; P < 0.05). Moreover, the MHO subjects and the CTL group showed an increase in cardiac output during the metaboreflex (288.7 ± 325.8 and 703.8 ± 276.2 ml/m increase with respect to baseline), whereas this parameter tended to decrease in the OMS group (−350 ± 236.5 ml/m). However, the blood pressure response, which tended to be higher in the OMS patients, was not statistically different between groups. The results of the present investigation suggest that OMS patients have an exaggerated vasoconstriction in response to metaboreflex activation and that this fact is not due to obesity per se.
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Affiliation(s)
- Raffaele Milia
- From the Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy; and
| | - Fernanda Velluzzi
- The Obesity Center of the Department of Medical Sciences of the University of Cagliari, Cagliari, Italy
| | - Silvana Roberto
- From the Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy; and
- The Obesity Center of the Department of Medical Sciences of the University of Cagliari, Cagliari, Italy
| | - Girolamo Palazzolo
- From the Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy; and
| | - Irene Sanna
- From the Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy; and
| | - Gianmarco Sainas
- From the Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy; and
- The Obesity Center of the Department of Medical Sciences of the University of Cagliari, Cagliari, Italy
| | - Matteo Pusceddu
- From the Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy; and
| | - Gabriele Mulliri
- From the Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy; and
- The Obesity Center of the Department of Medical Sciences of the University of Cagliari, Cagliari, Italy
| | - Andrea Loviselli
- From the Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy; and
- The Obesity Center of the Department of Medical Sciences of the University of Cagliari, Cagliari, Italy
| | - Antonio Crisafulli
- From the Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy; and
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Haemodynamics of aerobic and resistance blood flow restriction exercise in young and older adults. Eur J Appl Physiol 2015; 115:2293-302. [PMID: 26142277 DOI: 10.1007/s00421-015-3213-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 06/27/2015] [Indexed: 12/31/2022]
Abstract
PURPOSE Light-load blood flow restriction exercise (BFRE) may provide a novel training method to limit the effects of age-related muscle atrophy in older adults. Therefore, the purpose of this study was to compare the haemodynamic response to resistance and aerobic BFRE between young adults (YA; n = 11; 22 ± 1 years) and older adults (OA; n = 13; 69 ± 1 years). METHOD On two occasions, participants completed BFRE or control exercise (CON). One occasion was leg press (LP; 20 % 1-RM) and the other was treadmill walking (TM; 4 km h(-1)). Haemodynamic responses (HR, Q, SV and BP) were recorded during baseline and exercise. RESULT At baseline, YA and OA were different for some haemodynamic parameters (e.g. BP, SV). The relative responses to BFRE were similar between YA and OA. Blood pressures increased more with BFRE, and also for LP over TM. Q increased similarly for BFRE and CON (in both LP and TM), but with elevated HR and reduced SV (TM only). CONCLUSION While BFR conferred slightly greater haemodynamic stress than CON, this was lower for walking than leg-press exercise. Given similar response magnitudes between YA and OA, these data support aerobic exercise being a more appropriate BFRE for prescription in older adults that may contribute to limiting the effects of age-related muscle atrophy.
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Milia R, Roberto S, Mulliri G, Loi A, Marcelli M, Sainas G, Milia N, Marongiu E, Crisafulli A. Effect of aging on hemodynamic response to metaboreflex activation. Eur J Appl Physiol 2015; 115:1693-703. [DOI: 10.1007/s00421-015-3153-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/15/2015] [Indexed: 10/23/2022]
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Brandner CR, Kidgell DJ, Warmington SA. Unilateral bicep curl hemodynamics: Low-pressure continuous vs high-pressure intermittent blood flow restriction. Scand J Med Sci Sports 2014; 25:770-7. [DOI: 10.1111/sms.12297] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/23/2014] [Indexed: 11/30/2022]
Affiliation(s)
- C. R. Brandner
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences; Deakin University; Burwood Victoria Australia
| | - D. J. Kidgell
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences; Deakin University; Burwood Victoria Australia
| | - S. A. Warmington
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences; Deakin University; Burwood Victoria Australia
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Improvement in hemodynamic responses to metaboreflex activation after one year of training in spinal cord injured humans. BIOMED RESEARCH INTERNATIONAL 2014; 2014:893468. [PMID: 24809060 PMCID: PMC3997898 DOI: 10.1155/2014/893468] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 02/26/2014] [Indexed: 11/25/2022]
Abstract
Spinal cord injured (SCI) individuals show an altered hemodynamic response to metaboreflex activation due to a reduced capacity to vasoconstrict the venous and arterial vessels below the level of the lesion. Exercise training was found to enhance circulating catecholamines and to improve cardiac preload and venous tone in response to exercise in SCI subjects. Therefore, training would result in enhanced diastolic function and capacity to vasoconstrict circulation. The aim of this study was to test the hypothesis that one year of training improves hemodynamic response to metaboreflex activation in these subjects. Nine SCI individuals were enrolled and underwent a metaboreflex activation test at the beginning of the study (T0) and after one year of training (T1). Hemodynamics were assessed by impedance cardiography and echocardiography at both T0 and T1. Results show that there was an increment in cardiac output response due to metaboreflex activity at T1 as compared to T0 (545.4 ± 683.9 mL·min−1 versus 220.5 ± 745.4 mL·min−1, P < 0.05). Moreover, ventricular filling rate response was higher at T1 than at T0. Similarly, end-diastolic volume response was increased after training. We concluded that a period of training can successfully improve hemodynamic response to muscle metaboreflex activation in SCI subjects.
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Walls CE, Laine CM, Kidder IJ, Bailey EF. Human hypoglossal motor unit activities in exercise. J Physiol 2013; 591:3579-90. [PMID: 23690561 DOI: 10.1113/jphysiol.2013.252452] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The genioglossus (GG) muscle is considered the principal protruder muscle of the tongue that dilates and stiffens the pharyngeal airway. We recorded whole muscle and single motor unit (MU) activities in healthy adults performing progressive intensity exercise on a cycle ergometer. Tungsten microelectrodes were inserted percutaneously into the GG of 11 subjects (20-40 years) to record electromyographic (EMG) activities and pulmonary ventilation (VI) at rest and at workload increments up to 300 W. Increases in respiratory drive were associated with increases in VI, mean inspiratory flow (Vt/Ti) and tonic and phasic components of the GG EMG activity. In contrast, individual MUs typically showed expiration-related decreases in firing as exercise intensity increased. We suggest the decrease in MU activity may occur secondary to afferent feedback from lungs/chest wall and that compensation for more negative inspiratory airway pressures generated during heavy exercise occurs primarily via recruitment of previously silent MUs.
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Affiliation(s)
- Clinton E Walls
- Department of Physiology, College of Medicine, The University of Arizona, Tucson, AZ 85721-0093, USA
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Holwerda SW, Samels MR, Keller DM. Carotid baroreflex responsiveness in normotensive African Americans is attenuated at rest and during dynamic leg exercise. Front Physiol 2013; 4:29. [PMID: 23482843 PMCID: PMC3591748 DOI: 10.3389/fphys.2013.00029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 02/06/2013] [Indexed: 01/11/2023] Open
Abstract
Evidence suggests differences between African Americans (AAs) and Caucasian Americans (CAs) in cardiovascular responsiveness to physiological stressors. This study tested the hypothesis that carotid baroreflex (CBR) control of heart rate (HR) and blood pressure is reduced in AAs compared to CAs during exercise. Mean arterial pressure (MAP) and HR were continuously recorded at rest and during leg cycling in 23 non-hypertensive male subjects (12 AA; 11 CA; age 19–26 years). CBR control of HR and MAP was assessed with 5-s pulses of neck pressure (NP, simulated hypotension) and neck suction (NS, simulated hypertension) ranging from +45 to −80 Torr. Across all NS stimuli (−20, −40, −60, −80 Torr) at rest, the AA group demonstrated attenuated CBR-mediated reductions in HR (AA, −8.9 ± 1.9 vs. CA, −14.1 ± 2.3 bpm; P < 0.001) and MAP (AA, −6.4 ± 1 vs. CA, −7.8 ± 0.8 mmHg; P < 0.05). Despite similar gain and magnitude of resetting observed in the modeled stimulus response curves, an attenuation among AAs persisted in HR (AA, −8.2 ± 1.6 vs. CA, −11.8 ± 3 bpm; P < 0.05) and MAP (AA, −6.8 ± 0.9 vs. CA, −8.2 ± 1.1 mmHg; P < 0.05) responses to NS during exercise. No differences in CBR-mediated HR and MAP responses to NP were detected between groups at rest or during exercise. These data suggest impairment in the ability to defend against a hypertensive challenge among AAs during steady-state exercise compared to their CA counterparts.
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Affiliation(s)
- Seth W Holwerda
- Department of Medical Pharmacology and Physiology, University of Missouri Columbia, SC, USA
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Ahmadi-Noorbakhsh S, Malbrain MLNG. Integration of inspiratory and expiratory intra-abdominal pressure: a novel concept looking at mean intra-abdominal pressure. Ann Intensive Care 2012; 2 Suppl 1:S18. [PMID: 23282214 PMCID: PMC3527153 DOI: 10.1186/2110-5820-2-s1-s18] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The intra-abdominal pressure (IAP) is an important clinical parameter that can significantly change during respiration. Currently, IAP is recorded at end-expiration (IAPee), while continuous IAP changes during respiration (ΔIAP) are ignored. Herein, a novel concept of considering continuous IAP changes during respiration is presented. METHODS Based on the geometric mean of the IAP waveform (MIAP), a mathematical model was developed for calculating respiratory-integrated MIAP (i.e. MIAPri=IAPee+i⋅ΔIAP), where 'i' is the decimal fraction of the inspiratory time, and where ΔIAP can be calculated as the difference between the IAP at end-inspiration (IAPei) minus IAPee. The effect of various parameters on IAPee and MIAPri was evaluated with a mathematical model and validated afterwards in six mechanically ventilated patients. The MIAP of the patients was also calculated using a CiMON monitor (Pulsion Medical Systems, Munich, Germany). Several other parameters were recorded and used for comparison. RESULTS The human study confirmed the mathematical modelling, showing that MIAPri correlates well with MIAP (R2 = 0.99); MIAPri was significantly higher than IAPee under all conditions that were used to examine the effects of changes in IAPee, the inspiratory/expiratory (I:E) ratio, and ΔIAP (P <0.001). Univariate Pearson regression analysis showed significant correlations between MIAPri and IAPei (R = 0.99), IAPee (R = 0.99), and ΔIAP (R = 0.78) (P <0.001); multivariate regression analysis confirmed that IAPee (mainly affected by the level of positive end-expiratory pressure, PEEP), ΔIAP, and the I:E ratio are independent variables (P <0.001) determining MIAP. According to the results of a regression analysis, MIAP can also be calculated asMIAP=-0.3+IAPee+0.4⋅ΔIAP+0.5⋅IE. CONCLUSIONS We believe that the novel concept of MIAP is a better representation of IAP (especially in mechanically ventilated patients) because MIAP takes into account the IAP changes during respiration. The MIAP can be estimated by the MIAPri equation. Since MIAPri is almost always greater than the classic IAP, this may have implications on end-organ function during intra-abdominal hypertension. Further clinical studies are necessary to evaluate the physiological effects of MIAP.
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Affiliation(s)
| | - Manu LNG Malbrain
- Executive Committee, World Society of the Abdominal Compartment Syndrome (WSACS), Dreef 1, Lovenjoel, 3360, Belgium
- ICU and High Care Burn Unit, Department of Intensive Care, Ziekenhuis Netwerk Antwerpen (ZNA) Stuivenberg, Lange Beeldekensstraat 267, Antwerp, 2060, Belgium
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