The relationship between physical activity levels and measures of cognition and disease severity in prodromal Parkinson’s disease: A longitudinal study

BACKGROUND: Physical activity has been studied for its potential role in reducing motor symptoms of Parkinson's disease (PD). However, its impact on its prodromal phase remains underexplored. METHODS: We included 108 people with prodromal PD from the Parkinson's Progression Markers Initiative. We assessed their four-year longitudinal data of Physical Activity Scale for the Elderly, Movement Disorders Society-sponsored revision of the Unified Parkinson's Disease Rating Scale scores 1-3, Hopkins Verbal Learning Test-Revised, Letter-Number Sequencing test, and the Symbol Digit Modalities Test. RESULTS: Our linear mixed-effects model regression showed that physical activity (as assessed by the total, household-related, leisure-related, and work-related scores) had no significant associations with disease severity and cognitive function (p-values > 0.05). CONCLUSIONS: Our study found no significant associations between physical activity levels and cognitive function or PD symptoms. However, methodological limitations of the study suggest the need for further research to better understand the effects of physical activity on prodromal PD. TRIAL REGISTRATION: This study is a secondary analysis of de-identified data obtained from the Parkinson's Progression Markers Initiative (PPMI) observational cohort and did not directly involve prospective participant enrollment or intervention by the investigators. The PPMI study itself was registered on ClinicalTrials.gov (Identifier: NCT01141023) on 2010-06-10.