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Hanson BE, Casey DP. Intermittent versus continuous handgrip exercise and peripheral endothelial function: impact of shear rate fluctuations. J Appl Physiol (1985) 2023; 135:892-901. [PMID: 37650140 DOI: 10.1152/japplphysiol.00362.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/08/2023] [Accepted: 08/26/2023] [Indexed: 09/01/2023] Open
Abstract
Sustained exercise-induced elevations in shear rate (SR) have been well established as beneficial for improving endothelial function. However, the impact of intermittent fluctuations in SR is not understood. We investigated the effect of intermittent SR elevations compared with sustained elevations on peripheral endothelial function. Brachial artery flow-mediated dilation (FMD) was assessed in 13 adults (9 M/4 F; 22 ± 4 yr) before and after 30 min of handgrip exercise. Three different rhythmic forearm exercise interventions were performed at a rate of 20 contractions/min. Intermittent exercises (6 × 3 min exercise interspersed by 2 min of rest) were performed at 25% (INT-25%) and 15% (INT-15%) maximum voluntary contraction (MVC), and continuous exercise was completed at 15% MVC. Brachial artery diameter and velocity were measured using Doppler ultrasound. The total increase in SR above baseline throughout exercise was greater during INT-25% (4,441 ± 516 s-1) and continuous (4,070 ± 407 s-1) compared with INT-15% (2,811 ± 342 s-1, P < 0.05). The %FMD increased following all exercises (INT-25%: 5.7 ± 1.2% to 8.1 ± 1.2%; INT-15%: 5.2 ± 1.2% to 7.0 ± 1.1%; continuous: 5.5 ± 1.3% to 6.8 ± 1.3%, P < 0.05 for all). The increase following INT-25% was significantly greater than INT-15% and continuous (P < 0.05 for both). Normalized FMD to shear rate area under the curve increased with intermittent exercise (INT-25%: 2.2 ± 0.2% to 3.4 ± 0.3%; INT-15%: 2.1 ± 0.2% to 3.2 ± 0.2%, P < 0.05 for both) but did not following continuous (2.1 ± 0.2% to 2.5 ± 0.1%, P = 0.06). The increase in normalized FMD with intermittent exercises were greater than continuous (P < 0.05 for both). These findings suggest intermittent fluctuations in SR during handgrip exercise may be more beneficial than sustained elevations on improving peripheral endothelial function.NEW & NOTEWORTHY Exercise-induced increases in shear rate is a well-established stimulus for improving peripheral endothelial function. This study presents novel findings that intermittent elevations in shear rate may be more effective at acutely improving endothelial function compared with continuous elevations. Despite similar increases in total shear rate during handgrip exercise intermittent elevations produced a significantly greater increase in endothelial function when compared with continuous elevations potentially indicating intermittent elevations as a more effective stimulus for acute improvements.
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Affiliation(s)
- Brady E Hanson
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Darren P Casey
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States
- Abboud Cardiovascular Research Center, University of Iowa, Iowa City, Iowa, United States
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa, United States
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2
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Lopes KG, Farinatti P, Bottino D, Souza MDGD, Maranhão P, Bouskela E, Lourenço R, Oliveira RD. Exercise with blood flow restriction improves muscle strength and mass while preserving the vascular and microvascular function and structure of older adults. Clin Hemorheol Microcirc 2022; 82:13-26. [DOI: 10.3233/ch-221395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND: Changes in muscle mass, strength, vascular function, oxidative stress, and inflammatory biomarkers were compared in older adults after resistance training (RT) performed with low-intensity without blood flow restriction (RT-CON); low-intensity with BFR (RT-BFR); and high-intensity without BFR (RT-HI). METHODS: Thirty-two untrained individuals (72±7 y) performed a 12-week RT after being randomized into three groups: RT-CON –30% of 1 repetition maximum (RM); RT-BFR –30% of 1RM and mild BFR (50% of arterial occlusion pressure); RT-HI –70% of 1 RM. RESULTS: Improvements in handgrip strength were similar in RT-BFR (17%) and RT-HI (16%) vs. RT-CON (–0.1% ), but increases in muscle mass (6% vs. 2% and –1%) and IGF-1 (2% vs. –0.1% and –1.5%) were greater (p < 0.05) in RT-BFR vs. RT-HI and RT-CON. Changes in vascular function, morphology, inflammation, and oxidative stress were similar between groups, except for time to reach maximum red blood cell velocity which showed a greater reduction (p < 0.05) in RT-BFR (–55%) vs. RT-HI (–11%) and RT-CON (–4% ). CONCLUSION: RT with low intensity and mild BFR improved muscle strength and mass in older individuals while preserving vascular function. This modality should be considered an adjuvant strategy to improve muscle function in older individuals with poor tolerance to high loads.
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Affiliation(s)
- Karynne Grutter Lopes
- Laboratory for Clinical and Experimental Research on Vascular Biology, Rio de Janeiro State University, RJ, Brazil
| | - Paulo Farinatti
- Laboratory for Clinical and Experimental Research on Vascular Biology, Rio de Janeiro State University, RJ, Brazil
| | - Daniel Bottino
- Laboratory for Clinical and Experimental Research on Vascular Biology, Rio de Janeiro State University, RJ, Brazil
| | - Maria das Graças de Souza
- Laboratory for Clinical and Experimental Research on Vascular Biology, Rio de Janeiro State University, RJ, Brazil
| | - Priscila Maranhão
- Laboratory for Clinical and Experimental Research on Vascular Biology, Rio de Janeiro State University, RJ, Brazil
| | - Eliete Bouskela
- Laboratory for Clinical and Experimental Research on Vascular Biology, Rio de Janeiro State University, RJ, Brazil
| | - Roberto Lourenço
- Laboratory for Clinical and Experimental Research on Vascular Biology, Rio de Janeiro State University, RJ, Brazil
| | - Ricardo de Oliveira
- Laboratory for Clinical and Experimental Research on Vascular Biology, Rio de Janeiro State University, RJ, Brazil
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3
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Claassen JAHR, Thijssen DHJ, Panerai RB, Faraci FM. Regulation of cerebral blood flow in humans: physiology and clinical implications of autoregulation. Physiol Rev 2021; 101:1487-1559. [PMID: 33769101 PMCID: PMC8576366 DOI: 10.1152/physrev.00022.2020] [Citation(s) in RCA: 292] [Impact Index Per Article: 97.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Brain function critically depends on a close matching between metabolic demands, appropriate delivery of oxygen and nutrients, and removal of cellular waste. This matching requires continuous regulation of cerebral blood flow (CBF), which can be categorized into four broad topics: 1) autoregulation, which describes the response of the cerebrovasculature to changes in perfusion pressure; 2) vascular reactivity to vasoactive stimuli [including carbon dioxide (CO2)]; 3) neurovascular coupling (NVC), i.e., the CBF response to local changes in neural activity (often standardized cognitive stimuli in humans); and 4) endothelium-dependent responses. This review focuses primarily on autoregulation and its clinical implications. To place autoregulation in a more precise context, and to better understand integrated approaches in the cerebral circulation, we also briefly address reactivity to CO2 and NVC. In addition to our focus on effects of perfusion pressure (or blood pressure), we describe the impact of select stimuli on regulation of CBF (i.e., arterial blood gases, cerebral metabolism, neural mechanisms, and specific vascular cells), the interrelationships between these stimuli, and implications for regulation of CBF at the level of large arteries and the microcirculation. We review clinical implications of autoregulation in aging, hypertension, stroke, mild cognitive impairment, anesthesia, and dementias. Finally, we discuss autoregulation in the context of common daily physiological challenges, including changes in posture (e.g., orthostatic hypotension, syncope) and physical activity.
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Affiliation(s)
- Jurgen A H R Claassen
- Department of Geriatrics, Radboud University Medical Center, Donders Institute for Brain, Cognition, and Behaviour, Nijmegen, The Netherlands
| | - Dick H J Thijssen
- Department of Physiology, Radboud Institute for Health Sciences, Nijmegen, The Netherlands
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- >National Institute for Health Research Leicester Biomedical Research Centre, University of Leicester, Leicester, United Kingdom
| | - Frank M Faraci
- Departments of Internal Medicine, Neuroscience, and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, Iowa
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4
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Cardozo GG, Lopes KG, Bottino DA, Souza MDGCD, Bouskela E, Farinatti P, Brandão de Oliveira R. Acute effects of physical exercise with different levels of blood flow restriction on vascular reactivity and biomarkers of muscle hypertrophy, endothelial function and oxidative stress in young and elderly subjects - A randomized controlled protocol. Contemp Clin Trials Commun 2021; 22:100740. [PMID: 33937579 PMCID: PMC8076709 DOI: 10.1016/j.conctc.2021.100740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 11/15/2020] [Accepted: 02/04/2021] [Indexed: 11/26/2022] Open
Abstract
Background Gains in muscle mass and strength have been documented in exercise training with blood flow restriction (BFR). However, the impact of retrograde blood flow during BFR training on vascular health remains unclear. The present study designed a protocol to evaluate the acute effects of exercise performed with different levels of BFR on vascular reactivity and biomarkers of endothelial function, oxidative stress, and muscle hypertrophy in young and older individuals. Methods and study design Sixty-eight physically inactive eutrophic men [34 young (18–25-yrs old) and 34 elderly (≥65-yrs old)] will be included in the study. Subjects will undergo three experimental protocols: a) control (ExCON) – handgrip exercise with intensity of 30% of the maximum voluntary contraction (MVC); b) blood flow restriction (ExBFR) – handgrip exercise with a resistance of 30% of the MVC with low level of BFR [80% of arterial occlusion pressure at rest (rAOP)]; and c) arterial occlusion pressure (ExAOP) – handgrip exercise with a resistance of 30% of the MVC with high level of BFR (120% of rAOP). Primary outcomes will be: a) vascular reactivity assessed by venous occlusion plethysmography; b) endothelial function (nitric oxide and apoptotic endothelial micro particles; c) oxidative stress (thiobarbituric acid reactive substances). Growth hormone and lactate concentration will be measured as secondary outcomes reflecting the hypertrophic drive and metabolic stress, respectively. Discussion The findings of the present study may help to elucidate the age-related impacts of BFR training on the vascular health.
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Affiliation(s)
- Gustavo Gonçalves Cardozo
- Graduate Program in Exercise and Sport Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil.,Laboratory of Physical Activity and Health Promotion, Institute of Physical Education and Sports, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Karynne Grutter Lopes
- Laboratory of Physical Activity and Health Promotion, Institute of Physical Education and Sports, Rio de Janeiro State University, Rio de Janeiro, Brazil.,Graduate Program in Clinical and Experimental Physiopathology, Rio de Janeiro State University, Rio de Janeiro, Brazil.,Laboratory for Clinical and Experimental Research on Vascular Biology, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Daniel Alexandre Bottino
- Graduate Program in Clinical and Experimental Physiopathology, Rio de Janeiro State University, Rio de Janeiro, Brazil.,Laboratory for Clinical and Experimental Research on Vascular Biology, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Maria das Graças Coelho de Souza
- Graduate Program in Clinical and Experimental Physiopathology, Rio de Janeiro State University, Rio de Janeiro, Brazil.,Laboratory for Clinical and Experimental Research on Vascular Biology, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Eliete Bouskela
- Graduate Program in Clinical and Experimental Physiopathology, Rio de Janeiro State University, Rio de Janeiro, Brazil.,Laboratory for Clinical and Experimental Research on Vascular Biology, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Paulo Farinatti
- Graduate Program in Exercise and Sport Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil.,Laboratory of Physical Activity and Health Promotion, Institute of Physical Education and Sports, Rio de Janeiro State University, Rio de Janeiro, Brazil.,Graduate Program in Physical Activity Sciences, Salgado de Oliveira University, Niteroi, Brazil
| | - Ricardo Brandão de Oliveira
- Graduate Program in Exercise and Sport Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil.,Laboratory of Active Living - Rio de Janeiro State University, Rio de Janeiro, Brazil
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5
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Silva TOC, Sales ARK, Araujo GSM, Fonseca GWP, Braga PGS, Faria D, Rocha HNM, Rocha NG, Lima MF, Mady C, Negrão CE, Alves MJNN. Disturbed Blood Flow Acutely Increases Endothelial Microparticles and Decreases Flow Mediated Dilation in Patients With Heart Failure With Reduced Ejection Fraction. Front Physiol 2021; 12:629674. [PMID: 33776792 PMCID: PMC7991910 DOI: 10.3389/fphys.2021.629674] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 02/11/2021] [Indexed: 11/29/2022] Open
Abstract
Introduction Disturbed blood flow, characterized by high retrograde and oscillatory shear rate (SR), is associated with a proatherogenic phenotype. The impact of disturbed blood flow in patients with heart failure with reduced ejection fraction (HFrEF) remains unknown. We tested the hypothesis that acute elevation to retrograde and oscillatory SR provoked by local circulatory occlusion would increase endothelial microparticles (EMPs) and decrease brachial artery flow-mediated dilation (FMD) in patients with HFrEF. Methods Eighteen patients with HFrEF aged 55 ± 2 years, with left ventricular ejection fraction (LVEF) 26 ± 1%, and 14 control subjects aged 49 ± 2 years with LVEF 65 ± 1 randomly underwent experimental and control sessions. Brachial artery FMD (Doppler) was evaluated before and after 30 min of disturbed forearm blood flow provoked by pneumatic cuff (Hokanson) inflation to 75 mm Hg. Venous blood samples were collected at rest, after 15 and 30 min of disturbed blood flow to assess circulating EMP levels (CD42b−/CD31+; flow cytometry). Results At rest, FMD was lower in patients with HFrEF compared with control subjects (P < 0.001), but blood flow patterns and EMPs had no differences (P > 0.05). The cuff inflation provoked a greater retrograde SR both groups (P < 0.0001). EMPs responses to disturbed blood flow significantly increased in patients with HFrEF (P = 0.03). No changes in EMPs were found in control subjects (P > 0.05). Disturbed blood flow decreased FMD both groups. No changes occurred in control condition. Conclusion Collectively, our findings suggest that disturbed blood flow acutely decreases FMD and increases EMP levels in patients with HFrEF, which may indicate that this set of patients are vulnerable to blood flow disturbances.
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Affiliation(s)
- Thiago O C Silva
- Heart Institute, University of São Paulo Medical School, São Paulo, Brazil
| | - Allan R K Sales
- Heart Institute, University of São Paulo Medical School, São Paulo, Brazil.,D'OR Institute for Research and Education, São Paulo, Brazil
| | - Gustavo S M Araujo
- Heart Institute, University of São Paulo Medical School, São Paulo, Brazil
| | | | - Pedro G S Braga
- Heart Institute, University of São Paulo Medical School, São Paulo, Brazil
| | - Diego Faria
- D'OR Institute for Research and Education, São Paulo, Brazil
| | - Helena N M Rocha
- Department of Physiology and Pharmacology, Fluminense Federal University, Niteroi, Brazil
| | - Natalia G Rocha
- Department of Physiology and Pharmacology, Fluminense Federal University, Niteroi, Brazil
| | - Marta F Lima
- Heart Institute, University of São Paulo Medical School, São Paulo, Brazil
| | - Charles Mady
- Heart Institute, University of São Paulo Medical School, São Paulo, Brazil
| | - Carlos E Negrão
- Heart Institute, University of São Paulo Medical School, São Paulo, Brazil.,School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
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6
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da Cunha Nascimento D, Schoenfeld BJ, Prestes J. Potential Implications of Blood Flow Restriction Exercise on Vascular Health: A Brief Review. Sports Med 2020; 50:73-81. [PMID: 31559565 DOI: 10.1007/s40279-019-01196-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Blood flow restriction (BFR) exercise (a.k.a. occlusion training) has emerged as a viable surrogate to traditional heavy-load strength rehabilitation training for a broad range of clinical populations including elderly subjects and rehabilitating athletes. A particular benefit of BFR exercise is the lower stress upon the joints as compared to traditional heavy resistance training, with similar gains in muscle strength and size. The application of an inflatable cuff to the proximal portion of the limbs increases the pressure required for venous return, leading to changes in venous compliance and wall tension. However, it is not known if long-term benefits of BFR exercise on muscle strength and size outweigh potential short and long-term complications on vascular health. BFR exercise could lead to clinical deterioration of the vasculature along with sympathetic overactivity and decreased vascular function associated with retrograde shear stress. This raises a fundamental question: Given the concern that excessive restriction could cause injury to endothelial cells and might cause detrimental effects on endothelial function, even in healthy individuals, should we critically re-evaluate the safety of this method for the general population? From this perspective, the purpose of this manuscript is to review the effects of BFR exercise on vascular function, and to provide relevant insights for training practice as well as future directions for research.
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Affiliation(s)
- Dahan da Cunha Nascimento
- Department of Physical Education, Catholic University of Brasilia (UCB), Q.S. 07, Lote 01, EPTC-Bloco G. Código Postal, Distrito Federal, Brasilia, 71966-700, Brazil. .,Department of Physical Education, University Center of the Federal District (UDF), Brasilia, Brazil.
| | | | - Jonato Prestes
- Department of Physical Education, Catholic University of Brasilia (UCB), Q.S. 07, Lote 01, EPTC-Bloco G. Código Postal, Distrito Federal, Brasilia, 71966-700, Brazil
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7
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Miura K, Kashima H, Morimoto M, Namura S, Yamaoka Endo M, Oue A, Fukuba Y. Effects of Unilateral Arm Warming or Cooling on the Modulation of Brachial Artery Shear Stress and Endothelial Function during Leg Exercise in Humans. J Atheroscler Thromb 2020; 28:271-282. [PMID: 32595193 PMCID: PMC8049146 DOI: 10.5551/jat.55731] [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] [Indexed: 11/21/2022] Open
Abstract
Aim: We examined the effect of modulating the shear stress (SS) profile using forearm warming and cooling on subsequent endothelial function in the brachial artery (BA) during exercise. Methods: Twelve healthy young subjects immersed their right forearm in water (15°C or 42°C) during a leg cycling exercise at 120–130 bpm for 60 min. The same exercise without water immersion served as a control. The BA diameter and blood velocity were simultaneously recorded using Doppler ultrasonography to evaluate the antegrade, retrograde, and mean shear rates (SRs, an estimate of SS) before, during, and after exercise. The endothelial function in the right BA was evaluated using flow-mediated dilation (FMD) (%) using two-dimensional high-resolution ultrasonography before (baseline) and 15 and 60 min after exercise. Results: During exercise, compared with the control trial, higher antegrade and mean SRs and lower retrograde SRs were observed in the warm trial; conversely, lower antegrade and mean SRs and higher retrograde SRs were observed in the cool trial. At 15 min postexercise, no significant change was observed in the FMD from baseline in the warm (Δ%FMD: +1.6%, tendency to increase; p = 0.08) and control trials (Δ %FMD: +1.1%). However, in the cool trial, the postexercise FMD at 60 min decreased from baseline (Δ%FMD: −2.7%) and was lower than that of the warm (Δ%FMD: +1.5%) and control (Δ%FMD: +1.2%) trials. Accumulated changes in each SR during and after exercise were significantly correlated with postexercise FMD changes. Conclusion: Modulation of shear profiles in the BA during exercise appears to be associated with subsequent endothelial function.
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Affiliation(s)
- Kohei Miura
- Department of Exercise Science and Physiology, School of Health Sciences, Prefectural University of Hiroshima.,Department of Health and Nutrition, Faculty of Health Sciences, University of Hiroshima Shudo
| | - Hideaki Kashima
- Department of Exercise Science and Physiology, School of Health Sciences, Prefectural University of Hiroshima
| | - Marina Morimoto
- Department of Exercise Science and Physiology, School of Health Sciences, Prefectural University of Hiroshima
| | - Saki Namura
- Department of Exercise Science and Physiology, School of Health Sciences, Prefectural University of Hiroshima
| | - Masako Yamaoka Endo
- Department of Exercise Science and Physiology, School of Health Sciences, Prefectural University of Hiroshima
| | - Anna Oue
- Faculty of Food and Nutritional Sciences, Toyo University
| | - Yoshiyuki Fukuba
- Department of Exercise Science and Physiology, School of Health Sciences, Prefectural University of Hiroshima
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8
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Tymko MM, Tremblay JC, Bailey DM, Green DJ, Ainslie PN. The impact of hypoxaemia on vascular function in lowlanders and high altitude indigenous populations. J Physiol 2019; 597:5759-5776. [PMID: 31677355 DOI: 10.1113/jp277191] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/07/2019] [Indexed: 12/18/2022] Open
Abstract
Exposure to hypoxia elicits widespread physiological responses that are critical for successful acclimatization; however, these responses may induce apparent maladaptive consequences. For example, recent studies conducted in both the laboratory and the field (e.g. at high altitude) have demonstrated that endothelial function is reduced in hypoxia. Herein, we review the several proposed mechanism(s) pertaining to the observed reduction in endothelial function in hypoxia including: (i) changes in blood flow patterns (i.e. shear stress), (ii) increased inflammation and production of reactive oxygen species (i.e. oxidative stress), (iii) heightened sympathetic nerve activity, and (iv) increased red blood cell concentration and mass leading to elevated nitric oxide scavenging. Although some of these mechanism(s) have been examined in lowlanders, less in known about endothelial function in indigenous populations that have chronically adapted to environmental hypoxia for millennia (e.g. the Peruvian, Tibetan and Ethiopian highlanders). There is some evidence indicating that healthy Tibetan and Peruvian (i.e. Andean) highlanders have preserved endothelial function at high altitude, but less is known about the Ethiopian highlanders. However, Andean highlanders suffering from chronic mountain sickness, which is characterized by an excessive production of red blood cells, have markedly reduced endothelial function. This review will provide a framework and mechanistic model for vascular endothelial adaptation to hypoxia in lowlanders and highlanders. Elucidating the pathways responsible for vascular adaption/maladaptation to hypoxia has potential clinical implications for disease featuring low oxygen delivery (e.g. heart failure, pulmonary disease). In addition, a greater understanding of vascular function at high altitude will clinically benefit the global estimated 85 million high altitude residents.
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Affiliation(s)
- Michael M Tymko
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, British Columbia, Canada.,Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Joshua C Tremblay
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, British Columbia, Canada
| | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK
| | - Daniel J Green
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), University of Western Australia, Perth, Australia.,Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, British Columbia, Canada
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9
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Lopes KG, Bottino DA, Farinatti P, de Souza MDGC, Maranhão PA, de Araujo CMS, Bouskela E, Lourenço RA, de Oliveira RB. Strength training with blood flow restriction - a novel therapeutic approach for older adults with sarcopenia? A case report. Clin Interv Aging 2019; 14:1461-1469. [PMID: 31616137 PMCID: PMC6698614 DOI: 10.2147/cia.s206522] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 07/11/2019] [Indexed: 12/13/2022] Open
Abstract
Introduction A 91-year-old sedentary man presenting exhaustion, lower-limb weakness, hypertension, and history of multiple falls was diagnosed with sarcopenia – appendicular skeletal muscle mass index (ASM) of 7.10 kg/m2. Purpose To investigate the effects of strength training performed with low intensity in isolation (LI) or with blood flow restriction (LI-BFR) on strength, muscle mass, IGF-1, endothelial function, microcirculation, inflammatory biomarkers, and oxidative stress. Methods In the first 3 months, LI was performed with intensity corresponding to 30% of 1 repetition maximum, followed by 1 month of inactivity, and another 3 months of LI-BFR (similar load than LI concomitant to BFR equivalent to 50% of resting systolic blood pressure). Results LI-BFR, but not LI improved muscle mass, ASM, handgrip strength, isokinetic peak torque, IL-6, and IGF-1. Endothelial function, red blood cell velocity, and concentrations of C-reactive protein, and soluble intercellular adhesion molecules-1 improved after both LI and LI-BFR. Endothelin-1 and oxidative stress increased after LI-BFR, and lowered after LI. Conclusion LI-BFR, but not LI improved strength, muscle mass, IGF-1, endothelial function, and selected inflammatory markers in a nonagenarian sarcopenic patient. These results are promising and suggest that LI-BFR should be considered as an alternative to prevent muscle loss and improve functional fitness in frail older populations.
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Affiliation(s)
- Karynne Grutter Lopes
- Graduate Program in Clinical and Experimental Physiopathology, Faculty of Medical Sciences, Rio de Janeiro State University , Rio de Janeiro, Brazil.,Laboratory for Clinical and Experimental Research on Vascular Biology, Department of Physiological Sciences, Rio de Janeiro State University , Rio de Janeiro, Brazil
| | - Daniel Alexandre Bottino
- Graduate Program in Clinical and Experimental Physiopathology, Faculty of Medical Sciences, Rio de Janeiro State University , Rio de Janeiro, Brazil.,Laboratory for Clinical and Experimental Research on Vascular Biology, Department of Physiological Sciences, Rio de Janeiro State University , Rio de Janeiro, Brazil
| | - Paulo Farinatti
- Graduate Program in Physical Activity Sciences, Department of Physical Education, Salgado de Oliveira University , Niteroi, Brazil.,Laboratory of Physical Activity and Health Promotion, Institute of Physical Education and Sports, Rio de Janeiro State University , Rio de Janeiro, Brazil.,Graduate Program in Exercise and Sport Sciences, Institute of Physical Education and Sports, Rio de Janeiro State University , Rio de Janeiro, Brazil
| | - Maria das Graças Coelho de Souza
- Graduate Program in Clinical and Experimental Physiopathology, Faculty of Medical Sciences, Rio de Janeiro State University , Rio de Janeiro, Brazil.,Laboratory for Clinical and Experimental Research on Vascular Biology, Department of Physiological Sciences, Rio de Janeiro State University , Rio de Janeiro, Brazil
| | - Priscila Alves Maranhão
- Laboratory for Clinical and Experimental Research on Vascular Biology, Department of Physiological Sciences, Rio de Janeiro State University , Rio de Janeiro, Brazil
| | - Clara Maria Soares de Araujo
- Laboratory for Clinical and Experimental Research on Vascular Biology, Department of Physiological Sciences, Rio de Janeiro State University , Rio de Janeiro, Brazil
| | - Eliete Bouskela
- Graduate Program in Clinical and Experimental Physiopathology, Faculty of Medical Sciences, Rio de Janeiro State University , Rio de Janeiro, Brazil.,Laboratory for Clinical and Experimental Research on Vascular Biology, Department of Physiological Sciences, Rio de Janeiro State University , Rio de Janeiro, Brazil
| | - Roberto Alves Lourenço
- Research Laboratory on Human Aging, Internal Medicine Department, Faculty of Medical Sciences, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Ricardo Brandão de Oliveira
- Graduate Program in Clinical and Experimental Physiopathology, Faculty of Medical Sciences, Rio de Janeiro State University , Rio de Janeiro, Brazil.,Graduate Program in Exercise and Sport Sciences, Institute of Physical Education and Sports, Rio de Janeiro State University , Rio de Janeiro, Brazil.,Laboratory of Active Living, Rio de Janeiro State University, Institute of Physical Education and Sports , Rio de Janeiro, Brazil
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10
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Effect of external compression on femoral retrograde shear and microvascular oxygenation in exercise trained and recreationally active young men. Eur J Appl Physiol 2019; 119:1809-1818. [PMID: 31190212 DOI: 10.1007/s00421-019-04170-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 05/28/2019] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Retrograde shear causes endothelial damage and is pro-atherogenic. The purpose of our study was to examine the impact of vascular remodeling from habitual exercise training on acute changes in retrograde shear and microvascular oxygenation (SMO2) induced via 30 min of external compression. METHODS Participants included 11 exercise trained (ET) men (Division I track athletes; age 20 ± 3 years) and 18 recreationally active (RA) men (age 23 ± 5 years). Near-infrared spectroscopy (NIRS) was used to measure vastus medialis SMO2. Doppler-ultrasound was used to assess SFA intima-media thickness, diameter and flow velocity to derive retrograde shear. Vascular measures were made at baseline (BASELINE), during a sham condition (calf compression to 5 mmHg, SHAM) and during the experimental condition (calf compression to 60 mmHg, EXP). RESULTS Compared to RA, ET had larger SFA diameters (0.66 ± 0.06 vs 0.58 ± 0.06 cm, p < 0.05) and lower SFA IMT (0.33 ± 0.03 vs 0.36 ± 0.07 mm, p < 0.05). Retrograde shear increased similarly in both groups during EXP (p < 0.05) but ET men had lower overall retrograde shear during the conditions (BASELINE 75.8 ± 26.8 vs EXP 88.2 ± 16.9 s-1) compared to RA men (BASELINE 84.4 ± 23.3 vs EXP 106.4 ± 19.6 s-1p < 0.05). There was a similar increase in SMO2 from BASELINE to SHAM (ET + 8.1 ± 4.8 vs RA + 6.4 ± 9.7%) and BASELINE to EXP (ET + 8.7 ± 6.4 vs RA + 7.1 ± 9.0%) in both groups. CONCLUSION Beneficial vascular remodeling in ET men is associated with lower retrograde shear during external compression. Acute increases in retrograde shear with external compression do not detrimentally impact microvascular oxygenation.
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11
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Holder SM, Dawson EA, Brislane Á, Hisdal J, Green DJ, Thijssen DHJ. Fluctuation in shear rate, with unaltered mean shear rate, improves brachial artery flow-mediated dilation in healthy, young men. J Appl Physiol (1985) 2019; 126:1687-1693. [DOI: 10.1152/japplphysiol.00009.2019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increase in mean shear stress represents an important and potent hemodynamic stimulus to improve conduit artery endothelial function in humans. No previous study has examined whether fluctuations in shear rate patterns, without altering mean shear stress, impacts conduit artery endothelial function. This study examined the hypothesis that 30-min exposure to fluctuations in shear rate patterns, in the presence of unaltered mean shear rate, improves brachial artery flow-mediated dilation. Fifteen healthy men (27.3 ± 5.0 yr) completed the study. Bilateral brachial artery flow-mediated dilation was assessed before and after unilateral exposure to 30 min of intermittent negative pressure (10 s, −40mmHg; 7 s, 0 mmHg) to induce fluctuation in shear rate, while the contralateral arm was exposed to a resting period. Negative pressure significantly increased shear rate, followed by a decrease in shear rate upon pressure release (both P < 0.001). Across the 30-min intervention, mean shear rate was not different compared with baseline ( P = 0.458). A linear mixed model revealed a significant effect of time observed for flow-mediated dilation ( P = 0.029), with exploratory post hoc analysis showing an increase in the intervention arm (∆FMD +2.0%, P = 0.008), but not in the contralateral control arm (∆FMD +0.5%, P = 0.664). However, there was no effect for arm ( P = 0.619) or interaction effect ( P = 0.096). In conclusion, we found that fluctuations in shear patterns, with unaltered mean shear, improves brachial artery flow-mediated dilation. These novel data suggest that fluctuations in shear pattern, even in the absence of altered mean shear, represent a stimulus to acute change in endothelial function in healthy individuals. NEW & NOTEWORTHY Intermittent negative pressure applied to the forearm induced significant fluctuations in antegrade and retrograde shear rate, while mean shear was preserved relative to baseline. Our exploratory study revealed that brachial artery flow-mediated dilation was significantly improved following 30-min exposure to intermittent negative pressure. Fluctuations in blood flow or shear rate, with unaltered mean shear, may have important implications for vascular health; however, further research is required to identify the underlying mechanisms and potential long-term health benefits.
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Affiliation(s)
- Sophie M. Holder
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Ellen A. Dawson
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Áine Brislane
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
- School of Sport and Exercise Science, York St. John University, York, United Kingdom
| | - Jonny Hisdal
- Section of Vascular Investigations, Division of Cardiovascular and Pulmonary Diseases, Department of Vascular Surgery, Oslo University Hospital, Oslo, Norway
| | - Daniel J. Green
- School of Human Sciences (Exercise and Sports Science), The University of Western Australia, Crawley, Western Australia, Australia
| | - Dick H. J. Thijssen
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
- Radboud Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Radboud, the Netherlands
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12
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Garten RS, Darling A, Weggen J, Decker K, Hogwood AC, Michael A, Imthurn B, Mcintyre A. Aerobic training and vascular protection: Insight from altered blood flow patterns. Exp Physiol 2019; 104:1420-1431. [PMID: 31127657 DOI: 10.1113/ep087576] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 05/24/2019] [Indexed: 12/14/2022]
Abstract
NEW FINDING What is the central question of this study? This study sought to determine whether prior upper limb aerobic training can attenuate the vascular dysfunction resulting from negative alteration of blood flow patterns. What is the main finding and its importance? We demonstrated that the microvasculature of young men with prior upper limb aerobic training (rowing) was equally susceptible to negatively altered blood flow patterns when compared with untrained control subjects. This finding reveals that aerobic training does not provide adequate protection against this type of vascular insult, highlighting the importance of reducing known vascular insults regardless of training status. ABSTRACT Acute alteration of blood flow patterns can substantially reduce blood vessel function and, if consistently repeated, may chronically reduce vascular health. Aerobic exercise training is associated with improved vascular health, but it is not well understood whether aerobic training-induced vascular adaptations provide protection against acute vascular insults. This study sought to determine whether prior upper limb aerobic training can attenuate the vascular dysfunction resulting from an acute vascular insult (increased retrograde/oscillatory shear). Ten young arm-trained (AT) men (rowers; 22 ± 1 years of age) and 10 untrained (UT) male control subjects (21 ± 3 years of age) were recruited for this study. Subjects completed two brachial artery (BA) flow-mediated dilatation (FMD) tests separated by an acute bout of subdiastolic cuff inflation (SDCI) of the distal forearm. Brachial artery dilatation (normalized for the shear stimulus) and reactive hyperaemia evaluated during the BA FMD test were used to determine conduit artery and microvascular function, respectively. Data were presented as mean values ± SD. The AT group reported significantly greater whole body (peak oxygen uptake; P = 0.01) and forearm aerobic capacity (P < 0.001). The SDCI intervention significantly increased retrograde (P < 0.001) and oscillatory shear (P < 0.001) in both groups. After the SDCI, microvascular function (post-cuff release hyperaemia), but not conduit artery function (shear-induced BA dilatation), was significantly reduced from pre-SDCI values (P = 0.001) independent of group. This study revealed that young men with prior upper limb aerobic training, when compared with untrained control subjects, were equally susceptible to the microvascular dysfunction associated with an acute increase in retrograde/oscillatory shear.
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Affiliation(s)
- Ryan S Garten
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Ashley Darling
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Jennifer Weggen
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Kevin Decker
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Austin C Hogwood
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Austin Michael
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Brandon Imthurn
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Andrew Mcintyre
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA
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13
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Tremblay JC, Grewal AS, Pyke KE. Examining the acute effects of retrograde versus low mean shear rate on flow-mediated dilation. J Appl Physiol (1985) 2019; 126:1335-1342. [PMID: 30844335 DOI: 10.1152/japplphysiol.01065.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Arterial endothelial function is acutely and chronically regulated by blood flow-associated shear stress. An acute intervention employing modest forearm cuff occlusion to simultaneously increase retrograde and decrease mean brachial artery shear rate for 30 min evokes transient impairments in flow-mediated dilation (FMD). However, the independent influence of the low mean versus the retrograde shear stress components is unclear. Healthy young adults [n = 24 (12 women, 12 men); 22 ± 2 yr, body mass index = 25 ± 2 kg/m2 (mean ± SD)] completed three laboratory visits within 1 wk. Visits consisted of 45 min of supine rest followed by a brachial artery FMD test (duplex ultrasound) before and after a 30-min intervention: control (shear rate unchanged), cuff (mean shear rate decreased, retrograde shear rate increased), or arterial compression (mean shear rate decreased, no increase in retrograde shear rate). The mean shear rate on the compression visit was targeted to match that achieved on the cuff visit. Cuff and compression trials decreased mean shear rate to a similar extent (cuff: 43 ± 22 s-1, compression: 43 ± 21 s-1; P = 0.850) compared with control (65 ± 21 s-1; both P < 0.001), with the retrograde component elevated only in the former (cuff: -83 ± 30 s-1, compression: -7 ± 5 s-1; P < 0.001). FMD decreased by 29 ± 30% (P < 0.001) after the cuff intervention and 32 ± 24% (P < 0.001) after the compression trial but was unchanged on the control visit (-0.3 ± 18%; P = 0.754). This was not altered by accounting for the shear rate stimulus. An increased retrograde shear stress does not appear to be obligatory for the transient reduction in FMD achieved after a 30-min exposure to low mean shear stress. These findings provide novel mechanistic insight on the regulation of endothelial function in vivo. NEW & NOTEWORTHY Low mean and retrograde shear stress are considered atherogenic; however, their relative contribution to the acute regulation of endothelial function in humans is unclear. Matched reductions in mean shear stress (30 min), with and without increases in retrograde shear stress, elicited equivalent reductions in flow-mediated dilation in men and women. These findings afford novel insight regarding the shear stress components governing the acute (dys)regulation of conduit artery endothelial function in vivo.
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Affiliation(s)
- Joshua C Tremblay
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
| | - Arman S Grewal
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
| | - Kyra E Pyke
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
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14
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Tremblay JC, Stimpson TV, Pyke KE. Evidence of sex differences in the acute impact of oscillatory shear stress on endothelial function. J Appl Physiol (1985) 2018; 126:314-321. [PMID: 30382805 DOI: 10.1152/japplphysiol.00729.2018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Acutely imposed oscillatory shear stress (OSS) reduces reactive hyperemia flow-mediated dilation (RH-FMD) in conduit arteries of men; however, whether a similar impairment occurs in women or with FMD in response to a controlled, sustained shear stress stimulus (SS-FMD) is unknown. The purpose of this study was to determine the impact of OSS on RH-FMD and SS-FMD in men and women. OSS was provoked in the brachial artery using a 30-min forearm cuff inflation (70 mmHg). Healthy men [ n = 16, 25 yr (SD 3)] and women [ n = 16, 21 yr (SD 2)] completed the OSS intervention twice (separate days). Brachial artery endothelial function was assessed pre- and postintervention via either RH-FMD or 6 min of handgrip SS-FMD using Duplex ultrasound. The RH-FMD stimulus was calculated as shear rate area under the curve 60 s postdeflation (SRAUC60), whereas SS-FMD shear rate was targeted to produce a similar stimulus pre- and postintervention. The OSS intervention decreased RH-FMD in both sexes [men: 6.2% (SD 3.4) to 5.2% (SD 3.0); women: 5.4% (SD 2.0) to 3.1% (SD 1.8), P < 0.001), although this was accompanied by a reduced SRAUC60. There was no significant effect of the intervention on RH-FMD with SRAUC60 as a covariate ( P = 0.310). Handgrip exercise elicited a similar stimulus before and after the intervention ( P = 0.287) in men and women ( P = 0.873). Men demonstrated blunted SS-FMD [4.8% (SD 1.9) to 3.2% (SD 1.9), P < 0.001], whereas women displayed preserved SS-FMD following the intervention [3.5% (SD 1.9) to 4.0% (SD 1.9), P = 0.061]. The lower SS-FMD in men but not women following OSS provides evidence of sex differences in the effects of OSS on conduit artery endothelial function. NEW & NOTEWORTHY Acute exposure to oscillatory shear stress induces transient endothelial dysfunction in men; however, whether women experience similar impairments is unknown. Following acutely imposed oscillatory shear stress, there was a decrease in flow-mediated dilation stimulated by a physiologically relevant sustained increase in shear stress in men but not in premenopausal women. These findings demonstrate, for the first time in humans that there are sex differences in the impact of oscillatory shear stress on endothelial function.
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Affiliation(s)
- Joshua C Tremblay
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
| | - Taylor V Stimpson
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
| | - Kyra E Pyke
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
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15
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Disturbed blood flow induces endothelial apoptosis without mobilizing repair mechanisms in hypertension. Life Sci 2018; 209:103-110. [PMID: 30076919 DOI: 10.1016/j.lfs.2018.08.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 07/20/2018] [Accepted: 08/01/2018] [Indexed: 11/23/2022]
Abstract
AIMS The influence of blood flow disturbances on vascular function, endothelial activation and repair capacity has not been fully elucidated either in physiological conditions or in cardiovascular disease. We aimed to determine the impact of increases in retrograde blood flow (RBF) on vascular function, endothelial biomarkers and repair capacity in healthy subjects and patients with hypertension. MAIN METHODS In seven healthy (CT; 32 ± 15 yr) and eight hypertensive (HT; 34 ± 23 yr) men, flow mediated-dilation (FMD) was assessed before and 10 min after a 30-min maneuver to increase brachial artery RBF in which a pneumatic cuff was inflated to 75 mm Hg on forearm. Blood samples were obtained at rest and during the last minute of the maneuver. KEY FINDINGS Endothelial activation, apoptosis and endothelial progenitor cells (EPC) were measured by flow cytometry; nitrite was measured by ozone-chemiluminescence. No significant disparities were observed in FMD, endothelial activation and circulating EPC between groups at baseline (p > 0.05). However, HT presented higher resting endothelial apoptosis (p = 0.01 vs CT). Exacerbated RBF induced reductions in FMD (p = 0.02 vs baseline) and increases in endothelial activation in both groups (p = 0.049 vs baseline). Endothelial apoptosis increased only in HT (p = 0.02 vs baseline; p = 0.004 vs CT), whereas EPC (p = 0.02 vs baseline; p = 0.03 vs HT) and nitrite (p = 0.04 vs baseline; p = 0.004 vs HT) increased only in CT during the maneuver. SIGNIFICANCE While findings indicate that increased RBF impairs endothelial function and triggers the EPC mobilization in healthy subjects, patients with hypertension presented greater apoptosis and impaired repair capacity in response to RBF.
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16
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Ghardashi Afousi A, Izadi MR, Rakhshan K, Mafi F, Biglari S, Gandomkar Bagheri H. Improved brachial artery shear patterns and increased flow-mediated dilatation after low-volume high-intensity interval training in type 2 diabetes. Exp Physiol 2018; 103:1264-1276. [DOI: 10.1113/ep087005] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 06/19/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Alireza Ghardashi Afousi
- Department of Exercise Physiology, Faculty of Physical Education and Exercise Sciences; University of Tehran; Tehran IR Iran
| | - Mohammad Reza Izadi
- Department of Exercise Physiology, Faculty of Physical Education and Exercise Sciences; University of Shahid Chamran; Ahvaz IR Iran
| | - Kamran Rakhshan
- Department of Medical Physiology, Faculty of Medicine; Iran University of Medical Sciences; Tehran IR Iran
| | - Farnoosh Mafi
- Department of Exercise Physiology, Faculty of Physical Education and Exercise Sciences; University of Tehran; Tehran IR Iran
| | - Soheil Biglari
- Department of Exercise Physiology, Faculty of Physical Education and Exercise Sciences; University of Tehran; Tehran IR Iran
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17
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Buschmann EE, Li L, Brix M, Zietzer A, Hillmeister P, Busjahn A, Bramlage P, Buschmann I. A novel computer-aided diagnostic approach for detecting peripheral arterial disease in patients with diabetes. PLoS One 2018; 13:e0199374. [PMID: 29928037 PMCID: PMC6013098 DOI: 10.1371/journal.pone.0199374] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 06/06/2018] [Indexed: 12/19/2022] Open
Abstract
Peripheral arterial disease (PAD) is an important manifestation of systemic atherosclerosis, with diabetes being one of its most significant risk factors. Owing to medial arterial calcification (MAC), the ankle–brachial index (ABI) is not always a reliable tool for detecting PAD. Arterial Doppler flow parameters, such as systolic maximal acceleration (ACCmax) and relative pulse slope index (RPSI), may serve as effective surrogates to detect stenosis-induced flow alteration. In the present study, ACCmax and RPSI were prospectively evaluated in 166 patients (304 arteries) with clinical suspicion of PAD, including 76 patients with and 90 patients without diabetes. In the overall sample, the sensitivity of ACCmax (69%) was superior to that of ABI (58%) and RPSI (56%). In patients with diabetes, the sensitivity of ACCmax (57%), ABI (56%) and RPSI (57%) were similar, though a parallel test taking both ACCmax and RPSI into account further increased sensitivity to 68%. The specificity (98%) and accuracy (78%) of ACCmax were superior to those of ABI (83% and 70%, respectively), as were the specificity (95%) and accuracy (77%) of RPSI in patients with diabetes. The diagnostic properties of ACCmax and RPSI were superior to those of ABI for detecting PAD in patients with diabetes. Our acceleration algorithm (Gefäßtachometer®) provides a rapid, safe, noninvasive tool for identifying PAD in patients with diabetes.
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Affiliation(s)
- Eva Elina Buschmann
- Dept. for Cardiology, Center of Internal Medicine, Medical University Graz, Graz, Austria
- Dept. for Angiology, Center for Internal Medicine 1, Medical University Brandenburg (MHB), Brandenburg/ Havel, Germany
- * E-mail:
| | - Lulu Li
- Dept. for Angiology, Center for Internal Medicine 1, Medical University Brandenburg (MHB), Brandenburg/ Havel, Germany
- Richard-Thoma Laboratories for Arteriogenesis, Center for Cardiovascular Research (CCR), Charité Universitaetsmedizin Berlin, Berlin, Germany
| | - Michèle Brix
- Department of Physiology Charité Benjamin Franklin, Berlin, Germany
| | - Andreas Zietzer
- Richard-Thoma Laboratories for Arteriogenesis, Center for Cardiovascular Research (CCR), Charité Universitaetsmedizin Berlin, Berlin, Germany
- Medizinische Klinik II, Universität Bonn, Bonn, Germany
| | - Philipp Hillmeister
- Dept. for Angiology, Center for Internal Medicine 1, Medical University Brandenburg (MHB), Brandenburg/ Havel, Germany
- Richard-Thoma Laboratories for Arteriogenesis, Center for Cardiovascular Research (CCR), Charité Universitaetsmedizin Berlin, Berlin, Germany
| | | | - Peter Bramlage
- Dept. for Angiology, Center for Internal Medicine 1, Medical University Brandenburg (MHB), Brandenburg/ Havel, Germany
- Institute for Pharmacology and Preventive Medicine, Cloppenburg, Germany
| | - Ivo Buschmann
- Dept. for Angiology, Center for Internal Medicine 1, Medical University Brandenburg (MHB), Brandenburg/ Havel, Germany
- Richard-Thoma Laboratories for Arteriogenesis, Center for Cardiovascular Research (CCR), Charité Universitaetsmedizin Berlin, Berlin, Germany
- Department of Physiology Charité Benjamin Franklin, Berlin, Germany
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18
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Walsh LK, Restaino RM, Martinez-Lemus LA, Padilla J. Prolonged leg bending impairs endothelial function in the popliteal artery. Physiol Rep 2018; 5:5/20/e13478. [PMID: 29061865 PMCID: PMC5661238 DOI: 10.14814/phy2.13478] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 09/20/2017] [Indexed: 01/26/2023] Open
Abstract
Uninterrupted sitting blunts vascular endothelial function in the lower extremities; however, the factors contributing to this impairment remain largely unknown. Herein, we tested the hypothesis that prolonged flexion of the hip and knee joints, as it occurs during sitting, and associated low shear stress and disturbed (i.e., turbulent) blood flow caused by arterial bending, impairs endothelial function at the popliteal artery. Bilateral measurements of popliteal artery flow‐mediated dilation (FMD) were performed in 12 healthy subjects before and after a 3‐h lying‐down period during which one leg was bent (i.e., 90‐degree angles at the hip and knee) and the contralateral leg remained straight, serving as internal control. During the 3‐h lying down period, the bent leg displayed a profound and sustained reduction in popliteal artery blood flow and mean shear rate; whereas a slight but steady decline that only became significant at 3 h was noted in the straight leg. Notably, 3 h of lying down markedly impaired popliteal artery FMD in the bent leg (pre: 6.3 ± 1.2% vs. post: 2.8 ± 0.91%; P < 0.01) but not in the straight leg (pre: 5.6 ± 1.1% vs. post: 7.1 ± 1.2%; P = 0.24). Collectively, this study provides evidence that prolonged bending of the leg causes endothelial dysfunction in the popliteal artery. This effect is likely secondary to vascular exposure to low and disturbed blood flow resulting from arterial angulation. We conclude that spending excessive time with legs bent and immobile, irrespective of whether this is in the setting of sitting or lying‐down, may be disadvantageous for leg vascular health.
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Affiliation(s)
- Lauren K Walsh
- Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri
| | - Robert M Restaino
- Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Luis A Martinez-Lemus
- Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Jaume Padilla
- Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri .,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri.,Child Health University of Missouri, Columbia, Missouri
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19
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Tremblay JC, Howe CA, Ainslie PN, Pyke KE. UBC-Nepal Expedition: imposed oscillatory shear stress does not further attenuate flow-mediated dilation during acute and sustained hypoxia. Am J Physiol Heart Circ Physiol 2018. [PMID: 29522371 DOI: 10.1152/ajpheart.00717.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Experimentally induced oscillatory shear stress (OSS) and hypoxia reduce endothelial function in humans. Acute and sustained hypoxia may cause increases in resting OSS; however, whether this influences endothelial susceptibility to further increases in OSS is unknown. Healthy lowlanders ( n = 15, 30 ± 6 yr; means ± SD) participated in three OSS interventions: two interventions at sea level [normoxia and after 20 min of normobaric hypoxia (acute hypoxia, 11% O2)] and one intervention 5-7 days after a 9-day ascent to 5,050 m (sustained hypoxia). OSS was provoked in the brachial artery using a 30-min distal cuff inflation (75 mmHg). Endothelial function was assessed before and after each intervention by reactive hyperemia flow-mediated dilation (FMD). Shear stress magnitude and patterns were obtained via Duplex ultrasound. Baseline retrograde shear stress and OSS were greater in acute hypoxia versus normoxia ( P < 0.001), and OSS was elevated in sustained hypoxia versus normoxia ( P = 0.011). The intervention further augmented OSS during each condition. Preintervention FMD was decreased by 29 ± 48% in acute hypoxia and by 25 ± 31% in sustained hypoxia compared with normoxia ( P = 0.001 and 0.026); these changes correlated with changes in baseline mean and antegrade shear stress. After the intervention, FMD decreased during normoxia (-41 ± 26%, P < 0.001) and was unaltered during acute or sustained hypoxia. Therefore, a 30-min exposure to OSS reduced FMD during normoxia, a condition with an unchallenged, healthy endothelium; however, imposed OSS did not appear to worsen endothelial function during acute or sustained hypoxia. Exposure to an altered magnitude and pattern of shear stress at baseline in hypoxia may contribute to the insensitivity to further acute augmentation of OSS. NEW & NOTEWORTHY We investigated whether the endothelium remains sensitive to experimental increases in oscillatory shear stress in acute (11% O2) and sustained (2 wk at 5,050 m) hypoxia. Hypoxia altered baseline shear stress and decreased endothelial function (flow-mediated dilation); however, exposure to experimentally induced oscillatory shear stress only impaired flow-mediated dilation in normoxia.
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Affiliation(s)
- Joshua C Tremblay
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
| | - Connor A Howe
- Centre for Heart, Lung, and Vascular Health, University of British Columbia , Kelowna, British Columbia , Canada
| | - Philip N Ainslie
- Centre for Heart, Lung, and Vascular Health, University of British Columbia , Kelowna, British Columbia , Canada
| | - Kyra E Pyke
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
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20
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Barak OF, Mladinov S, Hoiland RL, Tremblay JC, Thom SR, Yang M, Mijacika T, Dujic Z. Disturbed blood flow worsens endothelial dysfunction in moderate-severe chronic obstructive pulmonary disease. Sci Rep 2017; 7:16929. [PMID: 29209035 PMCID: PMC5717042 DOI: 10.1038/s41598-017-17249-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 11/19/2017] [Indexed: 12/18/2022] Open
Abstract
The aims of this study were: (1) to test whether oscillatory shear stress further exacerbates endothelial dysfunction in patients with moderate-severe COPD, and (2) to test whether low flow oxygen administration improves endothelial function and is protective against oscillatory shear stress-induced endothelial dysfunction in patients with moderate-severe COPD. In 17 patients and 10 age-matched non-smoking control subjects we examined brachial artery flow-mediated dilation (FMD) and circulating microparticles before and after 20 minutes of experimentally-induced oscillatory shear stress. COPD patients performed this intervention a second time following a 20-minute wash in period of low flow supplemental oxygen to normalize arterial oxygen saturation. COPD patients had ~six-fold greater baseline retrograde shear rate (P < 0.05) and lower FMD (P < 0.05). The oscillatory shear stress intervention induced significant decreases in brachial artery FMD of all groups (P < 0.05). Oscillatory shear stress elevated circulating markers of endothelial cell apoptosis (CD31+/CD41b- microparticles) in COPD patients, but not age-matched controls. Supplemental oxygen administration abrogated the oscillatory shear stress-induced increase in CD31+/CD41b- microparticles, and improved FMD after accounting for the shear stress stimulus. We have demonstrated that acutely disturbed blood flow with increased retrograde shear stress further deteriorates the already impaired endothelial function with attendant endothelial apoptosis in patients with moderate-severe COPD.
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Affiliation(s)
- Otto F Barak
- Department of Physiology, Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia.,Department of Integrative Physiology, University of Split School of Medicine, Split, Croatia
| | - Suzana Mladinov
- Clinic for Pulmonary Diseases, University Hospital Centre Split, Split, Croatia
| | - Ryan L Hoiland
- Centre for Heart, Lung and Vascular Health, University of British Columbia, Okanagan Campus, Kelowna, British Columbia, Canada
| | - Joshua C Tremblay
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Stephen R Thom
- Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ming Yang
- Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Tanja Mijacika
- Department of Integrative Physiology, University of Split School of Medicine, Split, Croatia
| | - Zeljko Dujic
- Department of Integrative Physiology, University of Split School of Medicine, Split, Croatia.
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21
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Hydren JR, Richardson RS, Symons JD, Mynard JP, Smolich JJ, Ramos JS, Dias KA, Dalleck LC, Drummond C, Westerhof B, Westerhof N, Zuo L, Zhou T. Commentaries on Viewpoint: Origin of the forward-going "backward" wave. J Appl Physiol (1985) 2017; 123:1408-1410. [PMID: 29167201 DOI: 10.1152/japplphysiol.00758.2017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 08/24/2017] [Indexed: 11/22/2022] Open
Affiliation(s)
| | | | | | | | | | | | - Katrin A Dias
- Institute for Exercise and Environmental Medicine.,University of Texas Southwestern Medical Center
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22
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Green DJ, Hopman MTE, Padilla J, Laughlin MH, Thijssen DHJ. Vascular Adaptation to Exercise in Humans: Role of Hemodynamic Stimuli. Physiol Rev 2017; 97:495-528. [PMID: 28151424 DOI: 10.1152/physrev.00014.2016] [Citation(s) in RCA: 427] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
On the 400th anniversary of Harvey's Lumleian lectures, this review focuses on "hemodynamic" forces associated with the movement of blood through arteries in humans and the functional and structural adaptations that result from repeated episodic exposure to such stimuli. The late 20th century discovery that endothelial cells modify arterial tone via paracrine transduction provoked studies exploring the direct mechanical effects of blood flow and pressure on vascular function and adaptation in vivo. In this review, we address the impact of distinct hemodynamic signals that occur in response to exercise, the interrelationships between these signals, the nature of the adaptive responses that manifest under different physiological conditions, and the implications for human health. Exercise modifies blood flow, luminal shear stress, arterial pressure, and tangential wall stress, all of which can transduce changes in arterial function, diameter, and wall thickness. There are important clinical implications of the adaptation that occurs as a consequence of repeated hemodynamic stimulation associated with exercise training in humans, including impacts on atherosclerotic risk in conduit arteries, the control of blood pressure in resistance vessels, oxygen delivery and diffusion, and microvascular health. Exercise training studies have demonstrated that direct hemodynamic impacts on the health of the artery wall contribute to the well-established decrease in cardiovascular risk attributed to physical activity.
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Affiliation(s)
- Daniel J Green
- School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia; Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom; Radboud University Medical Center, Radboud Institute for Health Sciences, Department of Physiology, Nijmegen, The Netherlands; Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Department of Child Health, University of Missouri, Columbia, Missouri; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; Department of Biomedical Sciences, University of Missouri, Columbia, Missouri; and Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Maria T E Hopman
- School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia; Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom; Radboud University Medical Center, Radboud Institute for Health Sciences, Department of Physiology, Nijmegen, The Netherlands; Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Department of Child Health, University of Missouri, Columbia, Missouri; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; Department of Biomedical Sciences, University of Missouri, Columbia, Missouri; and Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Jaume Padilla
- School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia; Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom; Radboud University Medical Center, Radboud Institute for Health Sciences, Department of Physiology, Nijmegen, The Netherlands; Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Department of Child Health, University of Missouri, Columbia, Missouri; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; Department of Biomedical Sciences, University of Missouri, Columbia, Missouri; and Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - M Harold Laughlin
- School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia; Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom; Radboud University Medical Center, Radboud Institute for Health Sciences, Department of Physiology, Nijmegen, The Netherlands; Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Department of Child Health, University of Missouri, Columbia, Missouri; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; Department of Biomedical Sciences, University of Missouri, Columbia, Missouri; and Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Dick H J Thijssen
- School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia; Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom; Radboud University Medical Center, Radboud Institute for Health Sciences, Department of Physiology, Nijmegen, The Netherlands; Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Department of Child Health, University of Missouri, Columbia, Missouri; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; Department of Biomedical Sciences, University of Missouri, Columbia, Missouri; and Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
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23
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Romero SA, Gagnon D, Adams AN, Cramer MN, Kouda K, Crandall CG. Acute limb heating improves macro- and microvascular dilator function in the leg of aged humans. Am J Physiol Heart Circ Physiol 2016; 312:H89-H97. [PMID: 27836894 DOI: 10.1152/ajpheart.00519.2016] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/21/2016] [Accepted: 11/10/2016] [Indexed: 01/14/2023]
Abstract
Local heating of an extremity increases blood flow and vascular shear stress throughout the arterial tree. Local heating acutely improves macrovascular dilator function in the upper limbs of young healthy adults through a shear stress-dependent mechanism but has no such effect in the lower limbs of this age group. The effect of acute limb heating on dilator function within the atherosclerotic prone vasculature of the lower limbs of aged adults is unknown. Therefore, the purpose of this study was to test the hypothesis that acute lower limb heating improves macro- and microvascular dilator function within the leg vasculature of aged adults. Nine young and nine aged adults immersed their lower limbs at a depth of ~33 cm into a heated (~42°C) circulated water bath for 45 min. Before and 30 min after heating, macro (flow-mediated dilation)- and microvascular (reactive hyperemia) dilator functions were assessed in the lower limb, following 5 min of arterial occlusion, via Doppler ultrasound. Compared with preheat, macrovascular dilator function was unchanged following heating in young adults (P = 0.6) but was improved in aged adults (P = 0.04). Similarly, microvascular dilator function, as assessed by peak reactive hyperemia, was unchanged following heating in young adults (P = 0.1) but was improved in aged adults (P < 0.01). Taken together, these data suggest that acute lower limb heating improves both macro- and microvascular dilator function in an age dependent manner. NEW & NOTEWORTHY We demonstrate that lower limb heating acutely improves macro- and microvascular dilator function within the atherosclerotic prone vasculature of the leg in aged adults. These findings provide evidence for a potential therapeutic use of chronic lower limb heating to improve vascular health in primary aging and various disease conditions.
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Affiliation(s)
- Steven A Romero
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, Texas
| | - Daniel Gagnon
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, Texas
| | - Amy N Adams
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, Texas
| | - Matthew N Cramer
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, Texas
| | - Ken Kouda
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, Texas
| | - Craig G Crandall
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, Texas
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24
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Paiva FM, Vianna LC, Fernandes IA, Nóbrega AC, Lima RM. Effects of disturbed blood flow during exercise on endothelial function: a time course analysis. Braz J Med Biol Res 2016; 49:e5100. [PMID: 26909789 PMCID: PMC4792509 DOI: 10.1590/1414-431x20155100] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 11/10/2015] [Indexed: 01/22/2023] Open
Abstract
This study aimed to examine the time course of endothelial function after a single handgrip exercise session combined with blood flow restriction in healthy young men. Nine participants (28 ± 5.8 years) completed a single session of bilateral dynamic handgrip exercise (20 min with 60% of the maximum voluntary contraction). To induce blood flow restriction, a cuff was placed 2 cm below the antecubital fossa in the experimental arm. This cuff was inflated to 80 mmHg before initiation of exercise and maintained through the duration of the protocol. The experimental arm and control arm were randomly selected for all subjects. Brachial artery flow-mediated dilation (FMD) and blood flow velocity profiles were assessed using Doppler ultrasonography before initiation of the exercise, and at 15 and 60 min after its cessation. Blood flow velocity profiles were also assessed during exercise. There was a significant increase in FMD 15 min after exercise in the control arm compared with before exercise (64.09% ± 16.59%, P=0.001), but there was no change in the experimental arm (-12.48% ± 12.64%, P=0.252). FMD values at 15 min post-exercise were significantly higher for the control arm in comparison to the experimental arm (P=0.004). FMD returned to near baseline values at 60 min after exercise, with no significant difference between arms (P=0.424). A single handgrip exercise bout provoked an acute increase in FMD 15 min after exercise, returning to near baseline values at 60 min. This response was blunted by the addition of an inflated pneumatic cuff to the exercising arm.
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Affiliation(s)
- F M Paiva
- Faculdade de Educação Física, Universidade de Brasília, Brasília, DF, Brasil
| | - L C Vianna
- Faculdade de Educação Física, Universidade de Brasília, Brasília, DF, Brasil
| | - I A Fernandes
- Laboratório de Ciências do Exercício, Universidade Federal Fluminense, Niterói, RJ, Brasil
| | - A C Nóbrega
- Laboratório de Ciências do Exercício, Universidade Federal Fluminense, Niterói, RJ, Brasil
| | - R M Lima
- Faculdade de Educação Física, Universidade de Brasília, Brasília, DF, Brasil
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25
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Thijssen DHJ, Schreuder THA, Newcomer SW, Laughlin MH, Hopman MTE, Green DJ. Impact of 2-Weeks Continuous Increase in Retrograde Shear Stress on Brachial Artery Vasomotor Function in Young and Older Men. J Am Heart Assoc 2015; 4:e001968. [PMID: 26416875 PMCID: PMC4845130 DOI: 10.1161/jaha.115.001968] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 08/24/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Although acute elevation in retrograde shear rate (SR) impairs endothelial function, no previous study has explored the effect of prolonged elevation of retrograde SR on conduit artery vascular function. We examined the effect of 2-weeks elevation of retrograde SR on brachial artery endothelial function in young and in older men. METHODS AND RESULTS Thirteen healthy young (23±2 years) and 13 older men (61±5 years) were instructed to continuously wear a compression sleeve around the right forearm to chronically (2 weeks) elevate brachial artery retrograde SR in 1 arm. We assessed SR, diameter, and flow-mediated dilation in both the sleeve and contralateral control arms at baseline and after 30 minutes and 2 weeks of continuous sleeve application. The sleeve intervention increased retrograde SR after 30 minutes and 2 weeks in both young and older men (P=0.03 and 0.001, respectively). In young men, brachial artery flow-mediated dilation % was lower after 30 minutes and 2 weeks (P=0.004), while resting artery diameter was reduced after 2 weeks (P=0.005). The contralateral arm showed no change in retrograde SR or flow-mediated dilation % (P=0.32 and 0.26, respectively), but a decrease in diameter (P=0.035). In older men, flow-mediated dilation % and diameter did not change in either arm (all P>0.05). CONCLUSIONS Thirty-minute elevation in retrograde SR in young men caused impaired endothelial function, while 2-week exposure to elevated levels of retrograde SR was associated with a comparable decrease in endothelial function. Interestingly, these vascular changes were not present in older men, suggesting age-related vascular changes to elevation in retrograde SR.
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Affiliation(s)
- Dick H. J. Thijssen
- Department of PhysiologyRadboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
- Research Institute for Sport and Exercise ScienceLiverpool John Moores UniversityLiverpoolUnited Kingdom
| | - Tim H. A. Schreuder
- Department of PhysiologyRadboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | | | | | - Maria T. E. Hopman
- Department of PhysiologyRadboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Daniel J. Green
- Research Institute for Sport and Exercise ScienceLiverpool John Moores UniversityLiverpoolUnited Kingdom
- School of Sport Science, Exercise and HealthThe University of Western AustraliaCrawleyWestern AustraliaAustralia
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26
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Quinaglia T, Matos-Souza JR, Feinstein SB, Sposito AC. Flow-mediated dilation: An evolving method. Atherosclerosis 2015; 241:143-4. [PMID: 25982823 DOI: 10.1016/j.atherosclerosis.2015.05.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 05/08/2015] [Indexed: 11/16/2022]
Affiliation(s)
- Thiago Quinaglia
- Department of Cardiology, State University of Campinas, Sao Paulo, Brazil
| | | | - Steve B Feinstein
- Department of Internal Medicine, Section of Cardiology, Rush University Medical Center, Chicago, IL, USA
| | - Andrei C Sposito
- Department of Cardiology, State University of Campinas, Sao Paulo, Brazil.
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