Young P M, Rose M S, Sutton J R, Green H J, Cymerman A, Houston C S
US Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760.
J Appl Physiol (1985). 1989 Mar;66(3):1430-5. doi: 10.1152/jappl.1989.66.3.1430.
To examine the effect of hypobaric hypoxia on plasma lipid profiles, fasting blood samples were collected from six men (21-31 yr) at 760 Torr and periodically during a 40-day exposure to decreasing barometric pressure culminating in a final ambient pressure of 282 Torr. Preascent plasma total cholesterol concentration ([TC]) was decreased by 25% after the 40-day exposure (P less than 0.01). High-density lipoprotein concentrations ([HDL-C]) decreased 32% (P less than 0.001) with no alteration in the TC-to-HDL-C weight ratio. Plasma triglyceride concentration increased twofold during this period (P less than 0.01). There were no significant differences in fasting plasma free fatty acid concentrations or free fatty acid-to-albumin molar ratio throughout the study. Fasting plasma insulin levels were increased approximately twofold with no significant changes in glucagon concentration or the insulin-to-glucagon molar ratio. Plasma norepinephrine concentrations were increased threefold on reaching 282 Torr (P less than 0.01), with no significant changes in plasma epinephrine concentrations. Mean energy intake (kcal/day) decreased 42%, whereas mean body weights decreased by 8.9 +/- 0.8% (P less than 0.01) with exposure. Increased concentrations of insulin may lead to increased hepatic production of triglyceride-rich lipoproteins, thus eliciting metabolic changes independent of weight loss and dietary intake.
为研究低压缺氧对血浆脂质谱的影响，在760托（Torr）时从6名男性（21 - 31岁）采集空腹血样，并在40天逐渐降低气压直至最终环境压力为282托的暴露期间定期采集。40天暴露后，血浆总胆固醇浓度（[TC]）下降了25%（P < 0.01）。高密度脂蛋白浓度（[HDL-C]）下降了32%（P < 0.001），而TC与HDL-C的重量比无变化。在此期间血浆甘油三酯浓度增加了两倍（P < 0.01）。在整个研究过程中，空腹血浆游离脂肪酸浓度或游离脂肪酸与白蛋白的摩尔比无显著差异。空腹血浆胰岛素水平增加了约两倍，胰高血糖素浓度或胰岛素与胰高血糖素的摩尔比无显著变化。当达到282托时，血浆去甲肾上腺素浓度增加了三倍（P < 0.01），血浆肾上腺素浓度无显著变化。平均能量摄入量（千卡/天）下降了42%，而平均体重下降了8.9 ± 0.8%（P < 0.01）。胰岛素浓度升高可能导致肝脏产生富含甘油三酯的脂蛋白增加，从而引发独立于体重减轻和饮食摄入的代谢变化。
