The Effect Of Hypoxic Exercise On Reducing Vascular Response In Simulated Hypoxia In 4800m

Object:The stress of vascular is serious in acute mountain sickness, which hinders the body to adapt to the plateau. This study was designed to observe the vascular stress of native plains in a simulated altitude of 4800 meters, and observe the changes after 3 weeks of exercise in hypoxic environments, and analyze the mechanism.Method:53 male students of Beijing Sport University were the subjects. Firstly, measured BP, pulse wave velocity (PWV), and extracted vein blood 4ml in normoxia. Secondly, measured the same indicators in acute hypoxia (simulated altitude of 4,800 meters). Thirdly, did the hypoxia exercise (3 weeks,4 days per week and 2 hours per day), and the simulated altitude increased per week (2,500 meters,3,500 meters,4,500 meters). Finally, did the same test before exercise. And the indicators detected in blood were plasma NO, endothelin(ET) and angiotensinâ…¡(Angâ…¡).Results:(1) When exposed to acute hypoxia in 4800m, the quiet mean arterial pressure (MAP), systolic blood pressure (SBP), RbaPWV, LbaPWV and ET did not significantly change compared with in normoxia, and the quiet diastolic blood pressure(DBP), plasma NO and angiotensinâ…¡(Angâ…¡)reduced significantly, and SBP increased significantly during exercise, while a significant reduction in DBP. (2)After the hypoxic exercise, when re-exposed to hypoxia in 4,800 meters again, DBP at rest and was significantly different compared with normoxia, and SBP, MAP, plasma NO were still no significant change. The RbaPWV, LbaPWV at rest reduced significantly, but there was no significant change in exercise. Angâ…¡under normoxia significantly reduced compared with before exercise, and there was only a decreasing trend in ET.Conclusions:(1) Hypoxic exercise for 3 weeks improved the flexibility of blood vessels, help to improve compliance of vascular system, and reduce the hypoxic stress response in the vascular system. (2)The changes of plasma NO, Angâ…¡and ET did not correspond with changes in vascular elasticity, and the reason of changes in the vascular system compliance by hypoxic exercise might be other mechanisms.