Restless legs syndrome and Parkinson's disease in men.

We examined whether men with restless legs syndrome (RLS) have a higher prevalence of Parkinson's disease (PD) among 23,119 US participants of the Health Professional Follow-up Study who were free of diabetes and arthritis. RLS was assessed using a set of standardized questions recommended by the International RLS Study Group. PD cases were identified by self-reported questionnaires and confirmed by review of medical records. Compared to men without RLS, multivariate-adjusted odds ratios for PD were 1.1 (95% confidence interval: 0.4, 3.0) for men with RLS symptoms 5-14 times per month and 3.09 (95% confidence interval: 1.5, 6.2; P trend = 0.003) for those with symptoms 15 times or more per month, after adjusting for age, smoking, use of antidepressant, and other covariates. In conclusion, men with RLS are more likely to have concurrent PD. Prospective studies are warranted to clarify the temporal relationship between RLS and PD.