Abstract P377: Changes in Leisure-time Physical Activity and Risk of Ischemic and Hemorrhagic Stroke: The Atherosclerosis Risk in Communities Study

Introduction: Engagement in leisure-time physical activity (PA) levels recommended by the American Heart Association (AHA) is inversely associated with both ischemic and hemorrhagic stroke risk. PA levels fluctuate over the lifecourse, but the association between changes in PA from mid- to late-life and stroke risk is unknown. Hypothesis: Participants who maintained ideal levels of PA or increased their PA across 6 years will have lower ischemic and hemorrhagic stroke risk relative to those who had persistently poor PA. Methods: We included 11,658 participants of the Atherosclerosis Risk in Communities study without a history of CHD or stroke at visit 3 (1993-1995). Leisure-time PA was assessed using the modified Baecke questionnaire at visits 1 and 3 and categorized according to the AHA guidelines for PA (ideal, intermediate, or poor). All adjudicated definite and probable incident ischemic and hemorrhagic strokes between visit 3 and end of year 2013 were included. Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for ischemic and hemorrhagic stroke by categories of PA at visits 1 and 3. Those with poor PA at both visits were the referent group. We adjusted for age, sex, race/center, smoking, alcohol consumption, hypertension, diabetes mellitus, LDL, HDL, triglycerides, and body mass index. Results: During a median of 18.7 years of follow-up, 640 incident ischemic strokes and 76 hemorrhagic strokes occurred. In adjusted analyses, participants with ideal PA at both visits had a significantly lower ischemic stroke risk (HR=0.75 (0.59, 0.96)) but not significantly lower hemorrhagic stroke risk (HR=1.27 (0.65, 2.48)). Those whose PA levels increased from poor to ideal also had lower ischemic stroke risk (HR=0.74 (0.54, 1.03)) but not hemorrhagic stroke risk (HR=0.74 (0.28, 2.02)). Conclusion: Increasing PA between visit 1 and visit 3 was associated with lower ischemic stroke risk. Increasing PA may be an important component of stroke prevention.