A warmer indoor environment in the evening and shorter sleep onset latency in winter: The HEIJO-KYO study

PHYSIOLOGY & BEHAVIOR

卷:149

Article

Saeki, Keigo¹  Obayashi, Kenji¹  Tone, Nobuhiro²  Kurumatani, Norio¹ 

[1] Nara Med Univ, Sch Med, Dept Community Hlth & Epidemiol, Nara, Japan

[2] Nara Med Univ, Sch Med, Ctr Acad Ind & Govt Relat, Nara, Japan

关键词: Indoor temperature;    Bed temperature;    Sleep onset latency;    Actigraph;   

DOI  :  10.1016/j.physbeh.2015.05.022

来源: Elsevier

【 摘 要 】

Difficulty in initiating sleep is an important problem because it is associated with an increased incidence of depression, diabetes, myocardial infarction, and higher all-cause mortality. Although experimental studies in controlled settings have shown that warm skin temperature of the extremities (feet and hands) before bedtime is associated with shorter sleep onset latency (SOL), evidence from real life situations is limited. We assessed the relationship between indoor temperatures in the evening (2 h before bedtime) and SOL among 861 home-dwelling elderly participants. Subjective SOL was determined according to a self-administered sleep diary. Actigraphic (objective) SOL, indoor temperature, and bed temperature were simultaneously measured at participants' homes for 48 h during the colder seasons (October-April). The association between evening indoor temperature and SOL was assessed using a multilevel linear regression model with random intercept for individual participants. Evening indoor temperature showed a significant inverse association with log-transformed subjective SOL (beta = -0.021, P < 0.01) and actigraphic SOL (beta =- 0.019, P < 0.01), independent of potential con-founders including gender, insomnia medication, evening physical activity, and bedtime. Higher bed temperature during the 2 h after bedtime was significantly associated with shorter log-transformed actigraphic SOL (beta = -0.028, P < 0.01). These significant associations were maintained even after adjustment for evening outdoor temperature. The clinically important findings of the present study indicate that SOL may be shortened by modification of evening indoor temperature and bed temperature for 2 h after bedtime. (C) 2015 Elsevier Inc. All rights reserved.

【 授权许可】

Free