LEISURE-TIME PHYSICAL-ACTIVITY AND ISCHEMIC STROKE RISK - THE NORTHERN MANHATTAN STROKE STUDY

Background and Purpose-Physical activity reduces the risk of premature death and cardiovascular disease, but the relationship to stroke is l ess well studied. The objective of this study was to investigate the a ssociation between leisure-time physical activity and ischemic stroke in an urban, elderly, multiethnic population. Methods-The Northern Man hattan Stroke Study is a population-based incidence and case-control s tudy. Case subjects had first ischemic stroke, and control subjects we re derived through random-digit dialing with 1:2 matching for age, sex , and race/ethnicity. Physical activity was recorded through a standar dized in-person interview regarding the frequency and duration of 14 a ctivities over the 2 prior weeks. Conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals after adjustment for medical and socioeconomic confounders. Results-Over 30 months, 369 case subjects and 678 control subjects were enrolled. Mean age was 69.9+/-12 years; 57% were women, 18% whites, 30% blacks, and 52% Hispanics. Leisure-time physical activity was significantly protec tive for stroke after adjustment for cardiac disease, peripheral vascu lar disease, hypertension, diabetes, smoking, alcohol use, obesity, me dical reasons for limited activity, education, and season of enrollmen t (OR=0.37; 95% confidence interval=0.25 to 0.55). The protective effe ct of physical activity was detected in both younger and older groups, in men and women, and in whites: blacks, and Hispanics. A dose-respon se relationship was shown for both intensity (light-moderate activity OR=0.39; heavy OR=0.23) and duration (<2 h/wk OR=0.42; 2 to <5 h/wk OR =0.35; greater than or equal to 5 h/wk OR=0.31) of physical activity. Conclusions-Leisure-time physical activity was related to a decreased occurrence of ischemic stroke in our elderly, multiethnic, urban subje cts. More emphasis on physical activity in stroke prevention campaigns is needed among the elderly.