The effects of physical exercise at high altitude on adrenocortical function in humans.
The effects of physical exercise at high altitude on adrenocortical function in humans.
复制标题
高海拔体育锻炼对人类肾上腺皮质功能的影响。
作者：
E. Martignoni;Otto Appenzeller;R. Nappi;G. Sances;Alfredo Costa;Giuseppe Nappi
在喜马拉雅山进行科学考察期间，对14名健康志愿者（8男6女，平均年龄40.9±3.3岁）进行了持续体力活动和缺氧对肾上腺皮质功能的联合影响研究。在基础条件下和服用1 mg地塞米松（DXM） p.o后，测量所有受试者的血浆皮质醇水平。研究在高强度徒步旅行（列城，海拔3700米）之前和之后进行。尽管在这两种情况下，受试者的皮质醇昼夜波动都保持不变，但在高海拔地区，基础皮质醇水平和ddxm后的皮质醇水平显著高于攀登前（p < 0.005和p < 0.0005）。在低海拔的所有情况下，皮质醇都受到抑制，而在15天的徒步旅行后，14名受试者中有4人的激素水平没有下降。此外，非抑制者的皮质醇基线水平显著高于抑制者（p < 0.05）。发现基础和dxm后激素水平与受试者的年龄和性别无关。目前的数据进一步表明，在高海拔地区持续的体力活动可以激活正常人的肾上腺皮质功能；然而，在30%的受试者中，没有发生ddxm诱导的皮质醇抑制。为了解释后一种观察结果，应考虑到缺氧（和/或其他环境变化）和对物理应激源的主观感知的伴随作用。
The combined effects of sustained physical activity and hypoxia on adrenocortical function were investigated in 14 healthy volunteers, 8 males and 6 females (mean age 40.9 +/- 3.3 years), during a scientific expedition in the Himalayas. Plasma cortisol levels were measured in all subjects in basal conditions and after the administration of 1 mg dexamethasone (DXM) p.o. The study was performed before and after 15 days of intense trekking (Leh, altitude 3700 m). While on both occasions subjects retained their cortisol circadian fluctuations, basal and post-DXM cortisol levels at high altitude were significantly higher (p < 0.005 and p < 0.0005) than before climbing. Cortisol suppression was noted in all cases at low altitude, whereas 4 out of the 14 subjects did not show reduced hormone levels after 15 days of trekking. Moreover, nonsuppressor subjects had significantly higher (p < 0.05) baseline cortisol levels than suppressors. Basal and post-DXM hormone levels were found to be unrelated to age and sex of subjects. The present data further suggest that sustained physical activity at altitude activates adrenocortical function in normal individuals; however, in 30% of subjects DXM-induced cortisol suppression does not occur. To explain the latter observation, the concomitant role of hypoxia (and/or other environmental changes) and the subjective perception of physical stressors should be taken into account.