Physical activity and mortality across cardiovascular disease risk groups

Purpose: Several cohort studies suggest that sedentary individuals have an increased risk of death compared with individuals who are physically active. Most of these studies have been conducted in highly selected patient populations who tend to be healthier and are from higher socioeconomic status (SES) groups. We examined the impact of a sedentary lifestyle on mortality by cardiovascular disease (CVD) risk group in a national sample of U.S. adults who represent a wide range of activity levels, health conditions, and SES groups. Methods: Using data from the HRS, a nationally representative, observational study of 9824 U.S. adults aged 51-61 yr in 1992, we estimated the relative risk of death comparing sedentary individuals with those who are physically active by CVD risk group in a multivariate logistic regression model. Results: Even after adjusting for confounders, regular moderate to vigorous physical activity was associated with substantially lower overall mortality (odds ratio (OR) = 0.62 (95% CI 0.44-0.86)) compared with sedentary individuals. High CVD risk individuals (21% of the population) accounted for 64% of deaths attributable to a sedentary lifestyle. Those with high CVD risk had the most significant benefit from being active (regular moderate to vigorous exercisers OR = 0.55 (95% CI 0.31-0.97) and occasional or light exercisers OR 0.55 (95% CI 0.41-0.74)) compared with high CVD risk individuals who were sedentary. Conclusion: A sedentary lifestyle is associated with a higher risk of death in preretirement-aged U.S. adults. Individuals with high CVD risk appear to get the largest benefit from being physically active. Physical activity interventions targeting high CVD risk individuals should be a medical and public health priority.