Abstract
BACKGROUND: Physical activity, particularly regular aerobic exercise, is effective in preventing dementia. However, such activities are less feasible for patients with Parkinson's disease (PD) or other motor dysfunctions. OBJECTIVES: In this study, we investigated whether the minimal amount of exercise (MAE) through walking, which is practical for individuals with motor dysfunction, can reduce the risk of dementia in patients with PD. DESIGN: For this retrospective longitudinal study, we enrolled 470 patients with PD without dementia from 3 centers in Taiwan. METHODS: In total, 187 (39.8%) subsequently developed dementia, whereas 283 (60.2%) did not; the mean follow-up periods for these cohorts were 3.1 (range 0.3-6.1) and 2.4 (range 0.3-6.0) years, respectively. MAE was defined as walking approximately 1500-3000 steps or for 15-30 min. The patients were further stratified by the weekly frequency of MAE into MAE-no (frequency: 0), MAE-weekly (frequency: 1 or 2), and MAE-daily (frequency: ⩾3) groups, respectively. The incidence rates of dementia were compared among the three groups. Cox proportional-hazards analyses were performed to measure the effect of MAE on the incidence of dementia. The statistical model was adjusted for age, sex, education level, cognition level, activities of daily living, neuropsychiatric symptoms, vascular risk factors, and relevant medications. RESULTS: The MAE-weekly and MAE-daily groups were 0.69 (95% confidence interval (CI): 0.41-1.17) and 0.59 (95% CI: 0.41-0.84) times, respectively, less likely to develop dementia than the MAE-no group. When the MAE-weekly and MAE-daily groups were combined, the hazard ratio for dementia was 0.62 (95% CI: 0.45-0.85). Cox regression revealed that older age, female sex, atrial fibrillation, antidiabetic drug use, and poor daily function were associated with an increased incidence of dementia. CONCLUSION: MAE may help prevent dementia in patients with PD. This finding highlights the benefits of walking for patients with PD and, potentially, older adults with motor dysfunction due to various disorders.