Mortality reduction with physical activity in patients with and without cardiovascular disease

Abstract

Aims: 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.

Conclusion: Individuals with CVD may benefit from physical activity to a greater extent than do healthy subjects without CVD.

Keywords: Cohort study; Exercise; Metabolic equivalent; Physical activity; Risk reduction behaviour; Secondary prevention.

Figure 1

Incidence rate of mortality per 1000 person-years according to physical activity level stratified by cardiovascular disease. Numbers in the box plot indicate incidence rates per 1000 person-years. Error bars indicate 95% confidence intervals.

Figure 2

Distribution and adjusted risk of mortality according to physical activity levels stratified by cardiovascular disease. Cox regression analysis with physical activity classified as a categorical variable: 0 (totally sedentary), <500, 500 to 999, 1000 to 1499, and ≥1500 MET-min/week. The statistical models were adjusted for age, sex, income level, body mass index, hypertension, diabetes mellitus, dyslipidaemia, smoking, renal disease, end-stage renal disease, liver disease, any malignancy, fasting blood sugar, and serum creatinine levels. The red and blue lines indicate hazard ratios for subjects with and without CVD, respectively. Bar graph indicates the number of study subjects in each category.

Take home figure

Non-linear relationship between physical activity and mortality risk according to the presence of cardiovascular disease. Restricted cubic spline curves were constructed with regard to physical activity treated as a continuous variable. The red and blue lines and shades indicate adjusted hazard ratio and 95% confidence intervals for subjects with and without cardiovascular disease, respectively.

Figure 3

Non-linear relationship between physical activity and mortality risk according to the presence of cardiovascular disease and expected 10-year risk of fatal cardiovascular disease. Restricted cubic spline curves were constructed with regard to physical activity treated as a continuous variable. Adjusted hazard ratio and 95% confidence intervals are illustrated. The red, orange, green, and blue lines and shades indicate subjects with cardiovascular disease and subjects without cardiovascular disease who have an estimated 10-year risk of fatal cardiovascular disease ≥10%, 5–10%, and <5%, respectively.