No abstract

Incidence rates for parkinsonism and Parkinson disease were higher than those reported by most previous studies, possibly because of the authors' intensive case-finding methods involving in-person screening.

In a prospective population-based cohort study among 4,695 participants aged 55 years and older, with repeated in-person examination and on average 9.4 years of follow-up, we observed that higher serum levels of uric acid were associated with a significantly decreased risk of Parkinson disease (adjusted hazard ratio per standard deviation increase 0.71 [95% confidence interval 0.51-0.98]), with evidence for a dose-effect relationship (p value for trend over quartiles 0.040). Our findings support the hypothesis that oxidative stress contributes to the risk of Parkinson disease and suggest a potential protective effect of the natural antioxidant and free radical scavenger uric acid.

These findings suggest that high intake of unsaturated fatty acids might protect against Parkinson disease.

Several recent findings suggest a role of lipid and cholesterol metabolism in the pathogenesis of Parkinson's disease. Therefore, the authors examined the association between serum levels of cholesterol and the risk of Parkinson's disease in the prospective, population-based Rotterdam Study among 6,465 subjects aged 55 or more years with repeated in-person examination and on average 9.4 years of follow-up (1990-2004). Higher serum levels of total cholesterol were associated with a significantly decreased risk of Parkinson's disease (age- and sex-adjusted hazard ratio per mmol/liter increase in cholesterol = 0.77, 95% confidence interval: 0.64, 0.94), with evidence for a dose-effect relation. The association was restricted to women and remained unchanged after adjustment for multiple potential confounders. These findings may indicate a role of lipids in the pathogenesis of Parkinson's disease. Alternatively, they could reflect the strong correlation-especially in women-between levels of serum cholesterol and the antioxidant coenzyme Q10. If confirmed, this would provide further support for an important role of oxidative stress in the pathogenesis of Parkinson's disease.