Body mass index, sitting time, and risk of Parkinson disease

Objective Causes of Parkinson disease are largely unknown, but recent evidence suggests associations with physical activity and anthropometric measures. Methods We prospectively analyzed a cohort of 41,638 Swedish men and women by detailed assessment of lifestyle factors at baseline in 1997. Complete follow-up until 2010 was achieved through linkage to population-based registers. We used multivariable Cox proportional hazards models to estimate hazard ratios with 95% confidence intervals (CIs). Results We identified 286 incident cases of Parkinson disease during follow-up. Multivariable adjusted hazard ratios were 1.06 (95% CI 0.76-1.47) for sitting time >= 6 vs <6 hours per day; and 1.13 (95% CI 0.60-2.12) for body mass index >= 30 vs < 25 kg/m(2). Results did not differ by sex. Conclusions No association between prolonged sitting time per day or obesity and risk of Parkinson disease was found.