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.