Bed heating improves the sleep quality and health of the elderly who adapted to no heating in a cold environment

Since aging is associated with a progressive decrease in thermoregulation, a cold bedroom environment may have negative effects on the sleep quality of the elderly. This study investigated the effects of two bed heating methods (covering heating and mattress heating), compared with no heating, on sleep quality of the elderly without sleep disorders in a cold environment. Twelve elderly who did not use any heating in daily life participated into this field intervention experiment, which was performed in their own bedrooms. Sleep quality was subjectively evaluated using questionnaires in the morning and objectively measured with a wristband which continuously monitored throughout the sleep period. Skin temperatures and blood pressure were measured. The subjects felt thermally comfortable when slept in all conditions. Compared with no heating, covering heating and mattress heating increased the total sleep time by 35.5 min and 20.3 min, and decreased the sleep onset latency by 13.3 min and 18.3 min. Compared with mattress heating and no heating, the covering heating decreased the wake after sleep onset by 28.7 min and 12.5 min, and increased the sleep efficiency by 2.8% and 5.7%. Both two heating methods increased the bed temperature and reduced the skin temperature gradient between the chest and calf. The systolic blood pressure measured in the morning was significantly lower in the covering heating than in no heating. These results suggest that, without changing thermal comfort, bed heating improved micro thermal environment, sleep quality and health of the elderly without sleep disorders in a cold environment. (C) 2019 Elsevier B.V. All rights reserved.