Stevens G H, Graham T E, Wilson B A
Can J Physiol Pharmacol. 1987 Feb;65(2):165-71. doi: 10.1139/y87-032.
This study was conducted because of the paucity of information concerning gender differences in the cardiovascular and metabolic responses to cold stress. Lightly clad men (n = 8) and women (n = 8) were tested in 21 and 5 degrees C environments during a 20-min rest, followed by 20 min each of 50, 100, and 150 W of exercise. At 21 degrees C there was no gender differences in VO2 or cardiac output. Cold lowered skin temperature more in women than in men, but women demonstrated no differences in heart rate, stroke volume, or VO2 at 5 and 21 degrees C. The women's noradrenaline levels in the cold were higher than comparable 21 degrees C data at rest and 50 W and increased with work intensity in both tests. In contrast, men had a lower heart rate, higher stroke volume, and higher VO2 throughout the 5 degrees C treatment compared with 21 degrees C. The men's noradrenaline response to 5 degrees C was similar to that of women at rest and 50 W, but the level subsequently declined at 100 and 150 W. Thus, the women do not show a heart rate-stroke volume shift in either resting or exercising states in cold environments. Furthermore, the data fail to support that either skin cooling or changes in noradrenaline cause the bradycardia and enhanced stroke volume seen in men.
进行这项研究是因为关于寒冷应激对心血管和代谢反应的性别差异的信息匮乏。让穿着轻薄衣物的男性（n = 8）和女性（n = 8）在21摄氏度和5摄氏度的环境中进行测试，先休息20分钟，随后分别进行功率为50瓦、100瓦和150瓦的运动，各运动20分钟。在21摄氏度时，男女之间的摄氧量或心输出量没有性别差异。寒冷使女性皮肤温度下降幅度比男性更大，但女性在5摄氏度和21摄氏度时心率、每搏输出量或摄氧量没有差异。寒冷环境中女性的去甲肾上腺素水平高于在21摄氏度休息及50瓦运动时的可比数据，且在两项测试中均随运动强度增加而升高。相比之下，在整个5摄氏度的测试过程中，男性的心率低于21摄氏度时，每搏输出量和摄氧量高于21摄氏度时。男性对5摄氏度的去甲肾上腺素反应与女性在休息及50瓦运动时相似，但随后在100瓦和150瓦时水平下降。因此，女性在寒冷环境中的休息或运动状态下均未出现心率 - 每搏输出量的变化。此外，数据并不支持皮肤冷却或去甲肾上腺素变化会导致男性出现心动过缓和每搏输出量增加的现象。
