Association of modifiable behavioral risk factors with premature and all-cause mortality in patients with cardiovascular disease: A retrospective cohort study

Objective This study examined the separate and joint associations between modifiable behavioral risk factors (daily sitting time (DST), physical activity (PA) levels) and all-cause and premature mortality among individuals diagnosed with Cardiovascular Disease (CVD). Methods This retrospective cohort study analyzed data from 2,530 adult CVD patients in the National Health and Nutrition Examination Survey (2007–2018), and linked records to the National Death Index through December 31, 2019. Physical activity was categorized as high (≥500 MET-min/week) or low (<500 MET-min/week), while daily sitting time was classified as low (<7 hours/day) or high (≥7 hours/day). We used survey-weighted Cox regression, restricted cubic splines (RCS), and Kaplan-Meier survival analysis to evaluate relationships and conducted subgroup analyses to verify consistency. Results The cohort had a weighted mean age of 59.12±0.27 years (56.61% men, 68.01% non-Hispanic White), with 531 all-cause mortality (374 premature deaths). PA≥500 MET-min/week was associated with lower all-cause (HR = 0.49, 95% CI:0.37–0.64) and premature mortality (HR=0.44, 95% CI:0.32–0.61); Each 1-SD increase in PA was linked to 52% and 51% lower risks of all-cause and premature mortality. DST≥7 hours/day increased all-cause (HR=1.67, 95% CI:1.32–2.11) and premature mortality (HR=1.74, 95% CI:1.30–2.32); Each 1-SD increase in DST was linked to 31% and 33% higher risks of all-cause and premature mortality. The lowest mortality risk was among those with DST <7 hours/day and PA ≥500 MET-min/week (all-cause: HR = 0.37; premature: HR = 0.31). RCS showed linear positive associations for DST ( P for nonlinearity >0.05) and nonlinear negative associations for PA ( P for nonlinearity < 0.05) with mortality; subgroup analyses confirmed stable associations. Conclusions This study suggests that increasing physical activity and reducing daily sitting time may be associated with lower risks of all-cause mortality and premature death in patients with CVD, with more favorable effects observed when the two behaviors are combined. Promoting a combination of higher PA and lower DST may be a useful reference of routine CVD risk management.