Seasonal Effects of Sleep Deprivation on Thermoregulatory Responses in a Hot Environment

抄録

Effects of sleep deprivation and season on thermoregulation during 60 min. of leg-bathing (water temperature of 42°C, air temperature of 30°C, and relative humidity of 70%) were studied in eight men who completed all 4 experiments for normal sleep and sleep deprivation in summer and winter. Rectal temperature (T_re), skin temperature, total body sweating rate (M_sw-t), local sweating rate on the back (M_sw-back) and forearm (M_sw-forearm), and skin blood flow on the back (SBF_back) and forearm (SBF_forearm) were measured. The changes in T_re (ΔT_re) were smaller (P<0.05) for sleep deprivation than for normal sleep regardless of the season. This decrease in ΔT_re was significant only in summer (P<0.05). Mean skin temperature (T(mean of)_sk) was higher (P<0.05) for sleep deprivation than for normal sleep regardless of the season. M_sw-t was smaller (P<0.05) for sleep deprivation than for normal sleep regardless of season, although M_sw-back and M_sw-forearm were similar. SBF_back and SBF_forearm tended to be higher for sleep deprivation than normal sleep. The sensitivity of SBF to T_re was higher (P<0.05) for sleep deprivation than for normal sleep. These data indicate that seasonal differences in thermoregulation were small because of morning time. Sleep deprivation increased dry heat loss and restrained T_re rise, in spite of decreased sweating rate.