Physical activity and risk of Parkinson's disease and parkinsonism in a prospective population-based study (NEDICES)

To investigate whether physical activity (PA) is a protective factor for the incidence of Parkinson's disease (PD) and parkinsonism after three years of follow-up. All participants of this study were obtained from the Neurological Disorders in Central Spain (NEDICES), a prospective population-based cohort survey of older subjects (>= 65 years) that comprised 5278 census-based participants at baseline (1994-1995). A modified version of Rosow-Breslau questionnaire was applied to categorize PA into active versus sedentary group. The final diagnosis of PD and parkinsonism was made by an expert neurologist. Cox regression models (CRM) adjusted for several covariates (sex, age, education, alcohol consumption, tobacco, stroke, hypertension and body mass index) were used to calculate the association between PA (active group vs. sedentary) and risk of PD and parkinsonism after three years. 22 incident PD and 25 incident parkinsonism cases were identified among 2943 participants with available PA information (57.1% female; mean age = 73.28 +/- 6.24 years) after three years of follow-up. The CRM showed that the active group (vs. sedentary) showed a lower risk of parkinsonism (Hazard ratio (HR) = 0.18; 95% CI [0.07-0.51]; p = 0.0001). However, this effect was restricted to men (HR = 0.34; 95% CI [0.11-0.99], p < 0.05) for incident PD. PA may be a protective factor for incident parkinsonism, whereas this effect was only significant for men in the case of PD. The mechanisms implicated for brain maintenance in active individuals and the neurophysiological differences behind the role of sex on PD are discussed.