Background: There is significant evidence that physical activity has profound effects on the neurochemistry and plasticity of the brain and may prevent cognitive decline.
Objective: This study aimed to determine the association between physical activity and incident dementia among older Chinese adults.
Methods: In the prospective phase of the Shanghai Aging Study, 1,648 community-dwellers aged 60 years or older were followed for an average of 5 years. Their physical activity was assessed based on questionnaires. The physical activities were further transformed into metabolic equivalent values. A consensus diagnosis of incident dementia was ascertained based on medical, neurological, and neuropsychological data and the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition.
Results: We identified 166 incident dementia cases; the incidence rate was 19.4 per 1000 person-years. A multivariate Cox regression model indicated that compared to low levels of physical activity, medium-to-high levels of physical activity were associated with a reduced risk of dementia (hazard ratio, 95% confidence interval = 0.62, 0.44-0.89) after adjusting for age, sex, years of education, apolipoprotein E ɛ4, and other confounders.
Conclusion: Our findings demonstrate that medium-to-high level of physical activity is protective against dementia in older adults.
Keywords: Chinese; cognition; cohort studies; dementia; incidence; physical activity.