Journal article
Sex and vasodilator responses to hypoxia at rest and during exercise
Journal of applied physiology (1985), Vol.116(7), pp.927-936
Hypoxia
04/01/2014
DOI: 10.1152/japplphysiol.00409.2013
PMCID: PMC3972743
PMID: 23823148
Abstract
In humans, β-adrenergic receptor activation causes a substantial portion of hypoxic vasodilation in skeletal muscle at rest and during forearm exercise. Recent evidence suggests that β-adrenergic receptors are either more sensitive or upregulated in young women vs. men. Therefore, we examined whether sex influences hypoxic vasodilation in 31 young subjects (15 women/16 men; 26 ± 1 yr). We also examined whether potential sex-related differences existed in a group of older adults (6 women/5 men; 61 ± 2 yr). All subjects performed forearm exercise at 10 and 20% of maximum under normoxic and hypoxic [80% arterial O
2
saturation (S
o
2
)] conditions. Forearm vascular conductance (FVC; ml·min
−1
·100 mmHg
−1
) was calculated from blood flow (ml/min) and blood pressure (mmHg). At rest, young women demonstrated a greater vasodilator response to hypoxia compared with men (39 ± 12 vs. 13 ± 6%,
P
< 0.05). The absolute compensatory vasodilator response (hypoxic FVC-normoxic FVC) during exercise was similar between sexes, but the relative change was greater in young women at 10% (28 ± 5 vs. 17 ± 3%,
P
< 0.05) and 20% exercise (29 ± 4% vs. 15 ± 3%,
P
< 0.01). Additionally, the absolute changes in vasodilation after normalizing the response to forearm volume or workload were greater in young women during exercise (
P
< 0.05). Interestingly, the compensatory vasodilator responses between older women and men were similar at 10 and 20% exercise, regardless of whether the response is expressed as absolute, relative, or absolute change normalized for forearm volume or workload (
P
= 0.054–0.97). Our data suggest that the compensatory vasodilator response to hypoxic exercise is greater in young women compared with men. However, sex-specific differences appear to be lost with aging.
Details
- Title: Subtitle
- Sex and vasodilator responses to hypoxia at rest and during exercise
- Creators
- Darren P Casey - Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa; andJohn R. A Shepherd - Department of Anesthesiology, Mayo Clinic, Rochester, MinnesotaMichael J Joyner - Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota
- Resource Type
- Journal article
- Publication Details
- Journal of applied physiology (1985), Vol.116(7), pp.927-936
- Series
- Hypoxia
- DOI
- 10.1152/japplphysiol.00409.2013
- PMID
- 23823148
- PMCID
- PMC3972743
- NLM abbreviation
- J Appl Physiol (1985)
- ISSN
- 8750-7587
- eISSN
- 1522-1601
- Publisher
- American Physiological Society; Bethesda, MD
- Language
- English
- Date published
- 04/01/2014
- Academic Unit
- Physical Therapy and Rehabilitation Science; Fraternal Order of Eagles Diabetes Research Center
- Record Identifier
- 9984047700102771
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