2024 Volume 31 Issue 1 Pages 23-32
It is suggested that the average nocturnal heart rate shows a stronger correlation with mortality than resting heart rate or the average heart rate over a 24-hour period. This study elucidates which environmental factors most significantly impact the day-to-day variance of the average sleep heart rate (SHRAve) in the bedrooms where participants typically sleep during winter. Measurements were conducted in the regular bedrooms of 11 male and female participants. The indoor temperature, radiant temperature, humidity, illumination, and carbon dioxide concentration, during sleep were measured as the environmental factors in addition to the heart rate. For male participants, indoor and radiant temperatures showed a relatively large significant negative correlation. A multilevel structural equation model determined that the model incorporating operational temperature (OT) and carbon dioxide concentration best explained SHRAve. A significant negative correlation was found between each subject's average OT over the entire experimental period and their average heart rate. For all male participants, the SHRAve showed a positive trend with the average nocturnal carbon dioxide concentration. In the case of female participants, similar to summer studies, menstrual cycles must be considered, necessitating further experimentation.
