Independent and joint associations of sleep duration and physical activity with cardiovascular disease: a cross-sectional study of 1.6 million US adults.

BACKGROUND: Sleep duration and physical activity are intertwined determinants of cardiovascular health, yet their joint impact remains unclear. This study evaluated their independent, joint, and interactive associations with cardiovascular disease using a rigorous confounding adjustment framework. METHODS: We analyzed pooled data from 1,577,591 US adults in the Behavioral Risk Factor Surveillance System (2014-2022). Inverse probability of treatment weighting and doubly robust logistic regression were used. Additive interaction was assessed via RERI. RESULTS: Both short sleep (odds ratio, 1.26; 95% confidence interval, 1.22-1.30) and long sleep (odds ratio, 1.17; 95% confidence interval, 1.13-1.21) were independently associated with prevalent cardiovascular disease, as was physical inactivity (odds ratio, 1.11; 95% confidence interval, 1.09-1.14). The joint effect of short sleep and inactivity conferred the highest risk (odds ratio, 1.38; 95% confidence interval, 1.31-1.44). The relative excess risk due to interaction was -0.03 (95% confidence interval, -0.11 to 0.06), indicating additive, independent risks without synergy. CONCLUSION: By applying a rigorous adjustment framework, this study provides actionable, population-level evidence that moves beyond simple risk factor identification. Public health strategies should integrate sleep hygiene and physical activity into holistic "24-h movement" prescriptions.