Analysis of the dose-response relationship of leisure-time physical activity to cardiovascular disease and all-cause mortality: the REGICOR study.

Introduction And Objectives: Regular leisure-time physical activity (LTPA) has been consistently recognized as a protective factor for cardiovascular diseases (CVD) and all-cause mortality. However, the pattern of this relationship is still not clear. The aim of this study was to assess the relationship of LTPA with incident CVD and mortality in a Spanish population.

Methods: A prospective population-based cohort of 11 158 randomly selected inhabitants from the general population. LTPA was assessed by a validated questionnaire. Mortality and CVD outcomes were registered during the follow-up (median: 7.24 years). The association between LTPA and outcomes of interest (all-cause mortality and cardiovascular disease) was explored using a generalized additive model with penalized smoothing splines and multivariate Cox proportional hazard models.

Results: We observed a significant nonlinear association between LTPA and all-cause and CVD mortality, and fatal and nonfatal CVD. Moderate-vigorous intensity LTPA, but not light-intensity LTPA, were associated with beneficial effects. The smoothing splines identified a cutoff at 400 MET-min/d. Below this threshold, each increase of 100 MET-min/d in moderate-vigorous LTPA contributed with a 16% risk reduction in all-cause mortality (HR, 0.84; 95%CI, 0.77-0.91), a 27% risk reduction in CVD mortality (HR, 0.73; 95%CI, 0.61-0.87), and a 12% risk reduction in incident CVD (HR, 0.88; 95%CI, 0.79-0.99). No further benefits were observed beyond 400 MET-min/d.

Conclusions: Our results support a nonlinear inverse relationship between moderate-vigorous LTPA and CVD and mortality. Benefits of PA are already observed with low levels of activity, with a maximum benefit around 3 to 5 times the current recommendations.