Volume loading augments cutaneous vasodilatation and cardiac output of heat stressed older adults
Gagnon D, Romero SA, Ngo H, Sarma S, Cornwell WK, Poh PYS, Stoller D, Levine BD, Crandall CG
The Journal of physiology · 15 citations
How it was studied
- Design
- Controlled clinical trial (classified by our AI screen)
- Studied in
- People
- Main outcome
- Health markers and function
Who paid for it
- Funding
- Independent funding
- Government
- U.S. Department of Defense
- Nonprofit
- American College of Sports Medicine
- Government
- National Institutes of Health
- Government
- Natural Sciences and Engineering Research Council of Canada
- Government
- National Heart, Lung, and Blood Institute
- Government
- NHLBI NIH HHS
- Grants
- National Institutes of Health (1k23hl132048-01); National Heart, Lung, and Blood Institute (K23 HL132048); U.S. Department of Defense (W81XWH1210152); National Institutes of Health (GM‐068865)
Based on 6 listed funder(s).
Publication
- Published
- 2017-08-22 · J Physiol · vol. 595 · issue 20 · pp. 6489–6498
- Publisher
- Wiley
- Cited
- 18 citations · more than 70% of similar papers · 0.7× the field average
- References
- 39 works
- Access
- Open access (repository copy)
- Research areas
- Thermoregulation and physiological responses · Climate Change and Health Impacts · Infrared Thermography in Medicine
- Keywords
- Vasodilation, Cardiac output, Medicine, Cardiology, Volume (thermodynamics), Internal medicine, Hemodynamics, Thermodynamics, Physics
- MeSH
- skin, humans, heat stress disorders, cardiac output, vasodilation, adult, aged, female, male, hot temperature, skin physiological phenomena, young adult
9 authors
From CA, US
- Daniel GagnonMontreal Heart Institute; Texas Health Dallas; Presbyterian Hospital; Southwestern Medical Center; Institute for Exercise and Environmental Medicine; Université de Montréal; The University of Texas Southwestern Medical Center
- Steven A. RomeroTexas Health Dallas; Presbyterian Hospital; Southwestern Medical Center; Institute for Exercise and Environmental Medicine; The University of Texas Southwestern Medical Center
- Hai T. NgoTexas Health Dallas; Presbyterian Hospital; Southwestern Medical Center; Institute for Exercise and Environmental Medicine; The University of Texas Southwestern Medical Center
- Satyam SarmaTexas Health Dallas; Presbyterian Hospital; Southwestern Medical Center; Institute for Exercise and Environmental Medicine; The University of Texas Southwestern Medical Center
- William K. CornwellTexas Health Dallas; Presbyterian Hospital; Southwestern Medical Center; Institute for Exercise and Environmental Medicine; University of Colorado Anschutz; The University of Texas Southwestern Medical Center
- Paula Y. S. PohTexas Health Dallas; Presbyterian Hospital; Southwestern Medical Center; Institute for Exercise and Environmental Medicine; The University of Texas Southwestern Medical Center
Abstract
Key points
Age-related changes in cutaneous microvascular and cardiac functions limit the extent of cutaneous vasodilatation and the increase in cardiac output that healthy older adults can achieve during passive heat stress. However, it is unclear if these age-related changes in microvascular and cardiac functions maximally restrain the levels of cutaneous vasodilatation and cardiac output that healthy older adults can achieve during heat stress. We observed that rapid volume loading, performed during passive heat stress, augments both cutaneous vasodilatation and cardiac output in healthy older humans. These findings demonstrate that the microcirculation of healthy aged skin can further dilate during passive heat exposure, despite peripheral limitations to vasodilatation. Furthermore, healthy older humans can augment cardiac output when cardiac pre-load is increased during heat stress.
Abstract
Primary ageing markedly attenuates cutaneous vasodilatation and the increase in cardiac output during passive heating. However, it remains unclear if these responses are maximally restrained by age-related changes in cutaneous microvascular and cardiac functions. We hypothesized that rapid volume loading performed during heat stress would increase cardiac output in older adults without parallel increases in cutaneous vasodilatation. Twelve young (Y: 26 ± 5 years) and ten older (O: 69 ± 3 years) healthy adults were passively heated until core temperature increased by 1.5°C. Cardiac output (thermodilution), forearm vascular conductance (FVC, venous occlusion plethysmography) and cutaneous vascular conductance (CVC, laser-Doppler) were measured before and after rapid infusion of warmed saline (15 mL kg-1 , ∼7 min). While heat stressed, but prior to saline infusion, cardiac output (O: 6.8 ± 0.4 vs. Y: 9.4 ± 0.6 L min-1 ), FVC (O: 0.08 ± 0.01 vs. Y: 0.17 ± 0.02 mL (100 mL min-1 mmHg-1 )-1 ), and CVC (O: 1.29 ± 0.34 vs. Y: 1.93 ± 0.30 units mmHg-1 ) were lower in older adults (all P -1 ), FVC (O: +0.015 ± 0.007, Y: +0.048 ± 0.013 mL (100 mL min-1 mmHg-1 )-1 ), and CVC (O: +0.28 ± 0.10, Y: +0.29 ± 0.16 units mmHg-1 ) in both groups (all P < 0.01). The absolute increase in cardiac output and CVC were similar between groups, whereas FVC increased to a greater extent in young adults (P < 0.01). These results demonstrate that healthy older adults can achieve greater levels of cutaneous vasodilatation and cardiac output during passive heating.
Abstract via Europe PMC. Copyright remains with the authors or publisher.
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