Physical Activity and Incidence of Atrial Fibrillation in Older Adults: The Cardiovascular Health Study

Physical activity is often considered to increase the risk of atrial fibrillation (AF), on the basis of anecdotal reports, case series, and retrospective studies evaluating vigorous exertion and endurance training in younger and middle-aged athletes; however, most AF cases do not occur in athletes but in the general population of older adults ( 65 years old), in whom 10-year risk of AF approaches 20%. At these ages, AF risk factors include long-standing hypertension, reduced ventricular compliance, and structural heart disease, all of which are risk factors that might be improved or prevented by habitual light to moderate activity. However, relationships of physical activity with incidence of AF in older adults had not been evaluated. We prospectively investigated associations of habitual light to moderate activity, including leisure-time activities and walking, with AF incidence among 5446 adults 65 years of age over a 12-year period. After adjustment for other risk factors, both leisure-time activity and walking were associated with significantly lower AF incidence, including a 36% lower risk for the highest versus lowest quintile of leisure-time activity and a 50% lower risk for the highest versus lowest category of walking distance/pace. Strenuous exertion was not required: Lower risk was seen with regularly walking 5 to 10 blocks per week and at 2to 3-mph paces (greater distances and paces were associated with even lower risk). Although these observational findings do not prove causality, the strength and consistency of associations, including among individuals with and without preexisting cardiovascular disease, and the known biological effects of exercise suggest that regular light to moderate activity may reduce AF incidence in older adults. This provides additional strong impetus for clinicians and policy makers to focus on regular physical activity, including leisure-time activities and walking, to maintain cardiovascular health in older adults. See p 800.