Evolution of Circadian Syndrome status and Risk of Incident Stroke: A Longitudinal Cohort Study of Chinese Middle-Aged and Older Adults

Background: Circadian Syndrome (CircS), encompassing cardiometabolic and behavioral disruptions, has emerged as a potential risk factor for vascular disease.However, its longitudinal impact on stroke incidence remains unclear.Methods: Using data from the China Health and Retirement Longitudinal Study (CHARLS, 2011(CHARLS, -2020)), we examined the association between baseline CircS and incident stroke among 8,035 Chinese adults aged 40 years.A subset of 4,054 participants was analyzed to evaluate changes in CircS status and subsequent stroke risk.Cox proportional hazards models adjusted for demographic and clinical covariates were employed.Results: At baseline, participants with CircS had a significantly higher stroke incidence (1.43 vs. 0.69 per 1,000 person-years; adjusted hazard ratio (aHR): 2.18, 95% CI: 1.88-2.53).Compared to those with persistently normal CircS status, individuals with resolved (aHR: 2.20, 95% CI: 1.61-3.02),incident (aHR: 2.33, 95% CI: 1.66-3.28),and persistent CircS (aHR: 2.87, 95% CI: 2.19-3.77)exhibited progressively elevated risks of stroke.Associations remained consistent across age, sex, and behavioral subgroups.Conclusions: CircS and its dynamic evolution are strongly associated with incident stroke.Individuals with persistent CircS face the highest risk, while risk remains elevated even after resolution.