Objective: Owing to the lack of long-term observations and/or comprehensive adjustment for confounding factors, reliable conclusions regarding long-term effects of exercise and regular physical activity in Parkinson’s disease (PD) have yet to be drawn. Here, using data from the Parkinson’s Progression Markers Initiative study that includes longitudinal and comprehensive evaluations of many clinical parameters, we examined the long-term effects of regular physical activity and exercise habits on the course of PD.

Methods: In this observational cohort study, we primarily used the multivariate linear mixed-effects models to analyze the interaction effects of their regular physical activity and moderate-to-vigorous exercise levels, measured through the Physical Activity Scale for the Elderly questionnaire, on the progression of clinical parameters, after adjusting for age, sex, levodopa-equivalent dose, and disease duration. We also calculated bootstrapping 95% confidence intervals (CIs), and conducted sensitivity analyses using the multiple imputation method and subgroup analyses using the propensity score matching to match for all baseline background factors.

Results: 237 early PD patients [median (interquartile range); age, 63.0 (56.0–70.0) years; Male, 69.2%; follow-up duration, 5.0 (4.0–6.0) years] were included. Regular physical activity and moderate-to-vigorous exercise levels at the baseline did not significantly affect the subsequent clinical progression of PD. However, average regular overall physical activity levels over time were significantly associated with slower deterioration of postural and gait stability [standardized fixed-effects coefficients of the interaction term (βinteraction) = -0.10 (95% CI, -0.14 to -0.06)], activities of daily living [βinteraction = 0.08 (95% CI, 0.04 to 0.12)], and processing speed [βinteraction = 0.05 (95% CI, 0.03 to 0.08)] in PD patients. Moderate-to-vigorous exercise levels were preferentially associated with slower decline of postural and gait stability [βinteraction = -0.09 (95% CI, -0.13 to -0.05)] and work-related activity levels were primarily associated with slower deterioration of processing speed [βinteraction = 0.07 (95% CI, 0.04 to 0.09)]. Multiple imputation and propensity score matching confirmed the robustness of our results.

Conclusions: In the long-term, the maintenance of high regular physical activity levels and exercise habits was robustly associated with better clinical course of PD, with each type of physical activity having different effects.

This is an R code that aims to make the analysis done in this study transparent.