Social jet lag is associated with incident cardiovascular disease independent of sleep duration and cardiac genetic risk

BACKGROUND: Cardiovascular disease (CVD) remains the leading cause of mortality worldwide, yet many events occur in individuals not fully explained by traditional clinical and lifestyle factors. Social jet lag reflects misalignment between biological timing and socially imposed sleep schedules and may represent an overlooked behavioral circadian cardiovascular risk factor. OBJECTIVE: To determine whether accelerometer-derived social jet lag is independently associated with incident CVD beyond established clinical factors, sleep-related characteristics, and cardiac genetic risk. METHODS: Sleep timing was assessed using wrist accelerometry in 51,562 UK Biobank participants. Social jet lag was defined as the absolute difference between weekday and weekend mid-sleep timing. Participants were prospectively followed for incident CVD, including myocardial infarction, ischemic heart disease, heart failure, stroke, and atrial fibrillation (3853 events). RESULTS: Higher social jet lag was associated with increased CVD incidence after multivariable adjustment. Each standard deviation increase in social jet lag increased composite CVD risk (hazard ratio [HR] 1.05, 95% confidence interval [CI] 1.02-1.09, p = 0.0015). Individuals with ≥2 h of social jet lag had greater CVD risk (HR 1.30, 95% CI 1.11-1.54, p = 0.0014). Associations were strongest for myocardial infarction, ischemic heart disease, and heart failure. Severe social jet lag remained associated with CVD even among individuals with normal sleep duration, whereas sleep duration itself was not independently associated with risk. Social jet lag also remained independently associated with CVD after accounting for cardiac genetic risk. CONCLUSION: Social jet lag was associated with incident CVD independent of sleep duration and cardiac genetic susceptibility, supporting a role for circadian misalignment in cardiovascular pathophysiology.