Relationship between Dynamics of Physiological Signals and Subjective Quality of Life and Its Lifestyle Dependency

In terms of preventive healthcare, how adopted lifestyle maintains healthy states or leads to pathological states is an essential issue. In this study, for the healthy subjects, their daily patterns of heart rate variability (HRV) and behavioral activity dynamics were analyzed in association with subjective quality of life (QOL), and how the relationship between the physiological signal dynamics and QOL is differentiated by the chronotype (sleep-wake pattern) was investigated. As a result, the morning type subjects were found to show higher sequential variation in R-R interval (rMSSD) and behavioral activity, and to have higher sleep quality and non-depressive tendency. Even the evening type subjects could have higher sleep quality under the condition that rMSSD shows a dip around early afternoon and keep a higher level of activity during the daytime, which may be due to realization of steady entrainment to the circadian time cues. Through this study, fundamental knowledge for preventive healthcare was obtained for us to help people's choice of an appropriate lifestyle for their health.