Physical activity has been shown to reduce mortality in a dose-response fashion. Current guidelines recommend 500–1000 metabolic equivalent task (MET)-min per week of regular physical activity. This study aimed to compare the impact of leisure-time physical activity on mortality in primary versus secondary cardiovascular prevention.
Methods and results
This study included a total of 131 558 and 310 240 subjects with and without cardiovascular disease (CVD), respectively, from a population-based cohort. Leisure-time physical activity was measured by self-report questionnaires. The study subjects were followed-up for a median of 5.9 years, and the main study outcome was all-cause mortality. There was an inverse relationship between the physical activity level and the mortality risk in both groups. The benefit in the secondary prevention group was shown to be greater than that in the primary prevention group: every 500 MET-min/week increase in physical activity resulted in a 14% and 7% risk reduction in mortality in the secondary and primary prevention groups, respectively (interaction P < 0.001). In addition, while individuals without CVD benefited the most between 1 and 500 MET-min/week of physical activity, the benefit in those with CVD continued above 500 − 1000 MET-min/week. The adjusted mortality risk of individuals with CVD who performed a high level of physical activity (≥1000 MET-min/week) was shown to be comparable to or lower than that of their counterparts without CVD.
Individuals with CVD may benefit from physical activity to a greater extent than do healthy subjects without CVD.
Keywords: Physical activity, Secondary prevention, Cohort study, Exercise, Risk reduction behaviour, Metabolic equivalent