Abstract
OBJECTIVES: To determine the effect of walking on incident depressive symptoms in elderly Japanese-American men with and without chronic disease. DESIGN: Prospective cohort study. SETTING: The Honolulu-Asia Aging Study. PARTICIPANTS: Japanese-American men aged 71 to 93 at baseline. MEASUREMENTS: Physical activity was assessed according to self-reported distance walked per day. Depressive symptoms were measured using an 11-question version of the Centers for Epidemiologic Studies Depression Scale (CES-D 11) at the fourth examination (n=3,196) and at the seventh examination 8 years later (1999/00, n=1,417). Presence of incident depressive symptoms was defined as a CES-D 11 score of 9 or greater or taking antidepressants at Examination 7. Subjects with prevalent depressive symptoms at baseline were excluded. RESULTS: Age-adjusted 8-year incident depressive symptoms were 13.6%, 7.6%, and 8.5% for low (<0.25 miles/day), intermediate (0.25-1.5 miles/day), and high (>1.5 miles/day) walking groups at baseline (P=0.008). Multiple logistic regression analyses, adjusted for age, education, marital status, cardiovascular risk factors, prevalent diseases, and functional impairment, showed that those in the intermediate and highest walking groups had significantly lower odds of developing 8-year incident depressive symptoms (odds ratio (OR)=0.52, 95% confidence interval (CI)=0.32-0.83, P=.006 and OR=0.61, 95% CI= 0.39-0.97, P=.04, respectively). Analysis found that this association was significant only in participants without chronic diseases (coronary heart disease, cerebrovascular accident, cancer, Parkinson's disease, dementia, or cognitive impairment) at baseline. CONCLUSION: Daily physical activity (≥0.25 mile/day) is significantly associated with lower risk of 8-year incident depressive symptoms in elderly Japanese-American men without chronic disease at baseline.