Vigorous exertion and endurance training have been reported to increase atrial fibrillation (AF). Associations of habitual light or moderate activity with AF incidence have not been evaluated.
Methods and Results
We prospectively investigated associations of leisure-time activity, exercise intensity, and walking habits, assessed at baseline and updated during follow-up visits, with incident AF, diagnosed by annual 12-lead-electrocardiograms and hospital discharge records, from 1989–2001 among 5,446 adults ≥65 in the Cardiovascular Health Study. During 47,280 person-years follow-up, 1,061 new AF cases occurred (incidence=22.4/1,000 person-years). In multivariable-adjusted analyses, leisure-time activity was associated with lower AF incidence in a graded manner, with 25% (HR=0.75, 95%CI=0.61, 0.90), 22% (HR=0.78, 95%CI=0.65, 0.95), and 36% (HR=0.64, 95%CI=0.52, 0.79) lower risk in quintiles 3, 4, and 5, versus quintile 1 (p trend<0.001). Exercise intensity had a U-shaped relationship with AF (quadratic p=0.02): versus no exercise, AF incidence was lower with moderate (HR=0.72, 95%CI=0.58, 0.89), but not high (HR=0.87, 95%CI=0.64, 1.19), intensity exercise. Walking distance and pace were each associated with lower AF risk in a graded manner (p trend <0.001); assessing combined effects of distance/pace, individuals in quartile 2, 3, and 4 had 27% (HR=0.73, 95%CI=0.61, 0.86), 40% (HR=0.60, 95%CI=0.50, 0.73), and 48% (HR=0.52, 95%CI=0.42, 0.65) lower AF incidence, compared with quartile 1. Findings appeared unrelated to confounding by comorbidity or indication. Evaluating cutpoints of moderate leisure-time activity (~600 kcal/wk), walking distance (12 blocks/wk), and pace (2 mph), 26% of all new AF cases (95% CI=7, 43%) appeared attributable to absence of these activities.
Light to moderate physical activities, particularly leisure-time activity and walking, are associated with significantly lower AF incidence in older adults.