Serum uric acid levels and the risk of Parkinson disease

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. Ann Neurol 2005;58:797–800