Abstract

Objectives: The sleep-related changes in body temperature and the effects of ambient temperature on sleep gave rise to the thought that regulation of sleep and of body temperature are closely related. In this study, association of body temperature and level of sleepiness was investigated during total or partial sleep deprivation.

Study Design: Following the approval of local ethics committee, 13 healthy young adult males (age and BMI; 22±1 years, and 22.6±1.7 kg/m2, respectively) were enrolled in the study. Oral body temperature and sleepiness degree of all participants were recorded by two-hour intervals during 36 hours total sleep deprivation and one-night partial sleep deprivation under laboratory conditions. Association between body temperature and sleepiness at each recording point was investigated by the Spearman correlation test. Regression analysis was performed to determine the relation between the mean values.

Results: There was no significant association between body temperature and sleepiness during 36 hours total sleep deprivation. However, these two parameters were significantly related with each other during one-night partial sleep deprivation (r=0.828; p=0.02).

Conclusion: Our results suggest that level of sleepiness during sleep deprivation is determined initially by circadian factors (body temperature) and then by homeostatic factors (duration of sleep deprivation).