Integrated 24-Hour Time Use Patterns to Mediate Depression and Cardiovascular Disease Comorbidity: A Shared Lifestyle Pathway

Objective: To investigate how integrated patterns of time use behaviors (sleep, work, and physical activity) within a fixed limited time frame associate with health outcomes related to cardiovascular disease (CVD) and depression, as well as their potential mediating role in the relationship between depression and CVD. Participants and Methods: Using the National Health and Nutrition Examination Survey (NHANES 2005-2018), we analyzed cross-sectional (n≈37,939 to 42,395) and prospective cohort (n≈23,625 to 29,698) data. Outcomes included all-cause/cardiovascular mortality, major adverse cardiovascular events, CVD risk factors, and depression. A novel time use optimization algorithm defined 27 distinct behavioral patterns (classified as favorable, moderate, or unfavorable) based on joint sleep-work-activity ranges. Associations were assessed via Cox regression and generalized linear models; mediation analysis quantified behavioral contributions to depression-CVD comorbidity. Results: Among 23,625 participants, 6 favorable patterns (eg, stable work with protected sleep/activity) were associated with half the risk of all-cause mortality (hazard ratio, 0.52; 95% CI, 0.40 to 0.67) and depression (odds ratio, 0.50; 95% CI, 0.39 to 0.64) vs moderate patterns, alongside reduced cardiovascular risks. Three unfavorable patterns (eg, unemployment with sleep dysregulation) doubled mortality (hazard ratio, 2.06; 95% CI, 1.83 to 2.31) and depression risk (odds ratio, 2.47; 95% CI, 2.11 to 2.89). Crucially, these patterns mediated 44.4% (0.0023 of 0.0052) of the depression-major adverse cardiovascular events association and 44.6% (0.5521 of 1.2383) of the reverse association. Conclusion: Within the 24-hour time constraint, integrated sleep-work-activity patterns are strongly associated with cardiometabolic/mental health and mediate nearly half of depression-CVD comorbidity. This finding supports a paradigm shift toward personalized time use recommendations for joint disease prevention.