Association of healthy lifestyle, depression with all-cause or cardiovascular mortality modified by metabolic syndrome among individuals: evidence from US NHANES and UK biobank cohort studies

BACKGROUND: The quantitative effects of integrating healthy lifestyles with depression on mortality remain unclear. METHODS: A total of 19, 528 individuals from NHANES and 75, 785 participants from the UK Biobank were analyzed. The associations between combined healthy lifestyle and depression with mortality were evaluated using Cox proportional hazards regression and Kaplan-Meier survival curves. RESULTS: There were 855 or 2,286 instances of all-cause death and 249 or 405 instances of cardiovascular death, respectively. Participants exhibiting healthier lifestyle choices or better depression status had a reduced risk of death. Moreover, individuals adhering to a favorable lifestyle and concurrently staying mentally healthy had a reduced risk of all-cause and cardiovascular death compared to their counterparts (adjusted-HR: 0.37, 95% CI 0.27 to 0.51 for all-cause death, P < 0.001; adjusted-HR: 0.42, 95% CI 0.23 to 0.77, P = 0.027 for cardiovascular death in the NHANES database; adjusted-HR: 0.33, 95% CI 0.27 to 0.40 for all-cause death, P < 0.001; adjusted-HR: 0.40, 95% CI 0.24 to 0.67, P = 0.002 for cardiovascular death in the UK Biobank). Additionally, the joint association of lifestyle and depression categories on cardiovascular mortality was modified by metabolic syndrome. CONCLUSIONS: Subjects adhering to a favorable lifestyle and concurrently staying mentally healthy had a reduced risk of all-cause and cardiovascular death compared to their counterparts. This joint association of lifestyle and depression on cardiovascular mortality was modified by metabolic syndrome.