Physical activity and the risk of Parkinson disease

Objective: To investigate whether greater physical activity is associated with a lower risk of Parkinson disease (PD). Methods: The authors prospectively followed 48,574 men and 77,254 women who provided information on physical activity in 1986 or in early adulthood. During the follow-up, a total of 252 ( male) and 135 ( female) incident PD cases were identified. Results: In men, greater baseline physical activity was associated with a lower PD risk; compared with the lowest quintile, the multivariate relative risk (RR) of PD for the highest quintile was 0.7 (95% CI 0.5 to 1.1; p value, test for trend = 0.007), and the inverse association was still present after excluding the first 10 years of follow-up ( RR = 0.5; p value, test for trend = 0.02). Further, strenuous exercise in early adult life was also inversely related to PD risk in men: compared with men who regularly exercised less than or equal to2 months/year, those with greater than or equal to10 months of strenuous exercise had a 60% lower PD risk (RR = 0.4; p value, test for trend = 0.005). In women, physical activity assessed at baseline was not related to PD risk, whereas strenuous exercise in early adulthood tended to be inversely related to PD risk later in life ( highest vs lowest categories, RR = 0.5, 95% CI 0.2 to 1.4; p value, test for trend = 0.06). Conclusion: This study suggests either that higher levels of physical activity may lower the risk of Parkinson disease ( PD) in men or that men predisposed to PD tend to avoid strenuous physical activity in their early adult years.