Nonrestorative Sleep and Poor Self-Reported Physical and Mental Health among Middle-Aged Japanese Adults: A Cross-Sectional Study.

INTRODUCTION: Self-reported health is a robust indicator linked to mortality, morbidity, and health-related quality of life. Nonrestorative sleep-subjective unrefreshing sleep-is increasingly reported in middle-aged adults and is related to cardiometabolic and mental conditions, yet its relationship with perceived health in this group is underexplored. This study investigated the associations between nonrestorative sleep and poor self-reported physical and mental health among middle-aged adults in Japan. METHODS: A cross-sectional postal survey was conducted in 2020 using a self-administered questionnaire among 33,902 community residents aged 40-64 years in five cities of Osaka Prefecture, Japan. After excluding missing data, 11,086 participants remained for analysis. Physical and mental health were assessed with standardized rating items, dichotomized into "very good/good/average" versus "poor/very poor." Nonrestorative sleep was defined by the question, "Do you feel refreshed after a night's sleep?" with "no" indicating nonrestorative sleep. RESULTS: Among the study cohort, nonrestorative sleep was associated with increased risk ratios (RRs) for poor physical health (adjusted RR: 2.13; 95% confidence interval [CI]: 1.97-2.29) and poor mental health (adjusted RR: 2.21; 95% CI: 2.06-2.36). For participants without a history of present illness, the adjusted RRs were 2.55 (95% CI: 2.11-3.07) for poor physical health and 2.51 (95% CI: 2.18-2.89) for poor mental health. All models were adjusted for sociodemographic, behavioral, and health-related factors. Nonrestorative sleep consistently showed the highest RRs in the primary multivariable models. CONCLUSIONS: This large-scale study demonstrates that nonrestorative sleep is strongly associated with poor self-reported physical and mental health in middle-aged adults.