Effects of Moderate and Severe Intermittent Hypoxia on Vascular Endothelial Function and Haemodynamic Control in Sedentary Men.
From: Graduate Institute of Rehabilitation Science and Center for Gerontological Research, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan, 333, Taiwan. s5492@mail.cgu.edu.tw
European journal of applied physiology
- Publish Date: May 2007
- ISSN: 1439-6319
- Volume: 100
- Issue: 2
- Pages: 127-35
- Medium: Print
- Language: English
- Citation (JAMA): Wang Jong-Shyan, Chen Liang-Yu, Fu Li-Lan, et al. Effects of Moderate and Severe Intermittent Hypoxia on Vascular Endothelial Function and Haemodynamic Control in Sedentary Men.. Eur. J. Appl. Physiol. May 2007;100:127-35
Abstract
Acclimatization to intermittent hypoxia (IH) improves exercise performance by enhancing oxygen delivery and utilization, but the effect of IH on hemodynamic control remains unclear. This study investigates how two intensities of IH influence hemodynamic control to develop an IH regimen that improves aerobic fitness and minimizes risk of peripheral vascular disorder. Thirty healthy sedentary men were randomly divided into severe (SIH) and moderate (MIH) IH and control (C) groups. The subjects were exposed to 12% (SIH), 15% (MIH), or 21% (C) O2 for 1 h/day, 5 days/week for 4 weeks in a normobaric hypoxia chamber. The results demonstrate that (1) improved pulmonary ventilation and oxygen uptake by SIH and MIH; (2) SIH elevated blood pressure during exercise and increased plasma malondialdehyde and nitric oxide (NO) metabolite levels, accompanied by reduced hyperaemic arterial response, venous compliance, endothelium-dependent vasodilatation, and decreased plasma total antioxidant and vitamin E levels; (3) while such effects were not seen following MIH; and (4) there were no significant differences in endothelium-independent vasodilatation during all experimental periods among the three groups. We conclude that both SIH and MIH regimens improve pulmonary ventilation. However, SIH but not MIH decreases anti-oxidative capacity and increases lipid peroxidation in circulation, leading to suppression of vascular endothelial function, causing impairment of vascular haemodynamics.
Mesh Headings (Keywords): Adult, Anoxia, Atmosphere Exposure Chambers, Blood Pressure, Endothelium, Vascular, Exercise, Humans, Immobilization, Male, Oxygen, Time Factors
Check for Full Text / PubMed Unique Identifier (PMID): 17297625
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