Inoue Y
Department of Hygiene, Kobe University School of Medicine, Japan.
Eur J Appl Physiol Occup Physiol. 1996;74(1-2):72-7. doi: 10.1007/BF00376497.
To investigate longitudinal effects of age on heat-activated sweat gland density and output, eight healthy active men (mean age 65-70 years) were retested after 5-years using 60-min passive heating [by placing the lower legs and feet in a 42 degrees C water bath while sitting in a warm chamber (35 degrees C and 45% relative humidity)]. Their height, body mass, surface area-to-mass ratio, mean skinfold thickness, resting systolic and diastolic blood pressures, pedometer readings and estimated maximal oxygen uptake did not differ over the 5-years. During the 60-min exposure the increase of rectal temperature was significantly greater in the second test than in the initial test (P < 0.05), although mean skin temperature, metabolic heat production and heart rate did not differ. Total body sweating rate was significantly less in the second test than in the initial test [210 (SEM 13) vs 253 (SEM 16) g.m-2.h-1, P < 0.02]. The mean body temperature at the onset of sweating on the thigh was significantly higher in the second test (P < 0.04), but not on the back. Local sweat rate (msw) had decreased significantly on the back in the second test (P < 0.001), but had not changed on the thigh where it had been smaller (compared to younger men) in the initial test. The decreased msw on the back was due to a lower sweat gland output (SGO) per gland, but not from the recruitment of fewer glands. In contrast, the sweat gland density on the thigh was less in the second test than in the initial test [72 (SEM 4) vs 86 (SEM 7) glands.cm-2, P < 0.03], but the SGO which had shown considerably smaller values in the initial test remained unchanged. These results would suggest that sweat gland function decreased over 5 years in healthy active men in their sixth and seventh decades, despite their having similar physical characteristics and exercise habits. Furthermore, the decline did not occur uniformly over the body surface and it is suggested that it may well extend from the lower limbs to the trunk.
为研究年龄对热激活汗腺密度和排汗量的纵向影响，8名健康活跃男性（平均年龄65 - 70岁）在5年后接受重新测试，采用60分钟的被动加热方式（坐在温暖的房间里，将小腿和脚置于42摄氏度的水浴中，房间温度为35摄氏度，相对湿度为45%）。他们的身高、体重、体表面积与质量比、平均皮褶厚度、静息收缩压和舒张压、计步器读数以及估计的最大摄氧量在这5年中没有变化。在60分钟的暴露期间，第二次测试时直肠温度的升高显著大于初次测试（P < 0.05），尽管平均皮肤温度、代谢产热和心率没有差异。第二次测试时全身出汗率显著低于初次测试[210（标准误13）对253（标准误16）g·m⁻²·h⁻¹，P < 0.02]。第二次测试时大腿开始出汗时的平均体温显著更高（P < 0.04），但背部没有。第二次测试时背部的局部出汗率（msw）显著下降（P < 0.001），但大腿处的局部出汗率没有变化，初次测试时大腿处的局部出汗率就较小（与年轻男性相比）。背部msw的下降是由于每个腺体的汗腺排汗量（SGO）降低，而非腺体数量减少。相比之下，第二次测试时大腿的汗腺密度低于初次测试[72（标准误4）对86（标准误7）个腺体·cm⁻²，P < 0.03]，但初次测试时显示出明显较小值的SGO保持不变。这些结果表明，尽管处于六七十岁的健康活跃男性具有相似的身体特征和运动习惯，但5年后汗腺功能仍会下降。此外，这种下降并非在身体表面均匀发生，提示可能从下肢延伸至躯干。
