Okamoto-Mizuno K, Mizuno K, Michie S, Maeda A, Iizuka S
Department of Physiology, Dokkyo University School of Medicine, Shimotuga, Tochigi.
Sleep. 1999 Sep 15;22(6):767-73.
The objective of this study was to confirm the effect of humid heat exposure on sleep stages and body temperature. Seven healthy male volunteers with a mean age of 22.7+/-1.63, served as the subjects. The experiments were carried out under four different conditions of room temperature and relative humidity: 29 degrees C RH 50% (29/50), 29 degrees C RH 75% (29/75), 35 degrees C RH 50% (35/50), and 35 degrees C RH 75% (35/75). The subjects wearing only shorts slept from 23:00 to 7:00 on a bed, which was covered with a 100% cotton sheet. EEG, EOG, and mental EMG were recorded through the night. Rectal temperature (Tr) and skin temperature were measured continuously. The 35/75 condition caused more wake and a lower sleep efficiency index (SEI) and stage S3+S4 than 29/50 and 29/75. Stage REM and stage 3 were significantly decreased at 35/75 than at 29/50 and 35/50. Tr was maintained at a higher level at 35/75 than under the other conditions. Mean skin temperature was higher at 35/50 and 35/75 than at 29/50 and 29/75. These results suggest that humid heat exposure during night sleep increases the thermal load to supress the sleep-evoked Tr decrease, stage 3, SWS, and REM, and increase wakefulness.
本研究的目的是确认湿热暴露对睡眠阶段和体温的影响。七名平均年龄为22.7±1.63岁的健康男性志愿者作为受试者。实验在四种不同的室温和相对湿度条件下进行：29℃，相对湿度50%（29/50）；29℃，相对湿度75%（29/75）；35℃，相对湿度50%（35/50）；35℃，相对湿度75%（35/75）。仅穿短裤的受试者于23:00至7:00在床上睡觉，床上覆盖着100%的棉质床单。整夜记录脑电图（EEG）、眼电图（EOG）和精神肌电图（EMG）。连续测量直肠温度（Tr）和皮肤温度。与29/50和29/75相比，35/75条件下导致更多的觉醒，睡眠效率指数（SEI）和S3+S4期更低。与29/50和35/50相比，35/75条件下快速眼动（REM）期和3期显著减少。35/75条件下Tr维持在比其他条件更高的水平。35/50和35/75条件下的平均皮肤温度高于29/50和29/75条件下的。这些结果表明，夜间睡眠期间的湿热暴露会增加热负荷，以抑制睡眠引起的Tr下降、3期、慢波睡眠（SWS）和REM，并增加觉醒。
