Nocturnal change in body temperature, sleep quality in middle-aged women

Objective: The present study compared changes in body temperature during sleep, sleep quality (eg, subjective and objective sleep parameters) between middle-aged women and young women. Methods: Nineteen middle-aged women and 14 young women with normal menstrual cycles were recruited. Over 7 consecutive days, skin temperature and sleep parameters (subjectively and objectively analyzed using the Pittsburgh Sleep Quality Index [PSQI] and actigraphy, respectively) were assessed. For the PSQI, higher score means decreased quality of sleep. Results: The skin temperature during sleep was significantly higher in middle-aged women (35.0 ± 0.4℃) than young women (34.6 ± 0.5℃, P < 0.05). In young women, skin temperature increased immediately after bedtime and then gradually decreased, whereas skin temperature did not decrease in middle-aged women ( P < 0.05 between groups). In addition, skin temperature remained significantly higher in middle-aged women than young women during the 30%-80% phase for the entire night ( P < 0.05). Middle-aged women had a significantly higher PSQI score (5.4 ± 0.4) than young women (3.9 ± 0.4, P < 0.05), indicating that sleep quality was impaired in middle-aged women. However, no significant difference was found in objective sleep parameters between middle-aged women and young women. Conclusion: Middle-aged women had significantly higher body temperatures during sleep than younger women. A sustained higher body temperature during sleep may be associated with decreased sleep quality, as evaluated by the PSQI.