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

Accession number;03A0865405
Title;Seasonal Effects of Sleep Deprivation on Thermoregulatory Responses in a Hot Environment
Author; FUJITA M (Kyushu Univ.) LEE D (Kyushu Univ.) ISMAIL M S (Kyushu Univ.) TOCHIHARA Y (Kyushu Univ.)
Journal Title;J Physiol Anthropol Appl Hum Sci
Journal Code:Y0932A
ISSN:1345-3475
VOL.22;NO.6;PAGE.273-278(2003)
Figure&Table&Reference;FIG.4, TBL.3, REF.30
Pub. Country;Japan
Language;English
Abstract;Effects of sleep deprivation and season on thermoregulation during 60 min. of leg-bathing (water temperature of 42.DEG.C., air temperature of 30.DEG.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 (Tre), skin temperature, total body sweating rate (Msw-t), local sweating rate on the back (Msw-back) and forearm (Msw-forearm), and skin blood flow on the back (SBFback) and forearm (SBFforearm) were measured. The changes in Tre (.DELTA.Tre) were smaller (P<0.05) for sleep deprivation than for normal sleep regardless of the season. This decrease in .DELTA.Tre was significant only in summer (P<0.05). Mean skin temperature (Tsk) was higher (P<0.05) for sleep deprivation than for normal sleep regardless of the season. Msw-t was smaller (P<0.05) for sleep deprivation than for normal sleep regardless of season, although Msw-back and Msw-forearm were similar. SBFback and SBFforearm tended to be higher for sleep deprivation than normal sleep. The sensitivity of SBF to Tre 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 Tre rise, in spite of decreased sweating rate. (author abst.)
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