Serum Uric Acid in Patients with Parkinson’s Disease and Vascular Parkinsonism: A Cross-Sectional Study

<b><i>Background:</i></b> Elevation of serum uric acid (UA) is correlated with a decreased risk of Parkinson’s disease (PD); however, the association and clinical relevance of serum UA levels in patients with PD and vascular parkinsonism (VP) are unknown. <b><i>Objective:</i></b> We performed a cross-sectional study of 160 Chinese patients with PD and VP to determine whether UA levels in patients could predict the outcomes. <b><i>Methods:</i></b> Serum UA levels were divided into quartiles and the association between UA and the severity of PD or VP was investigated in each quartile. <b><i>Results:</i></b> The serum levels of UA in PD were significantly lower than those in normal subjects and VP. The serum UA levels in PD patients were significantly correlated with some clinical parameters. Strong correlations were observed in male PD patients, but significant correlations were observed only between UA and the non-motor symptoms (NMS) of burden of sleep/fatigue and mood in female PD patients. PD patients in the lowest quartile of serum UA levels had significant correlations between UA and the unified Parkinson’s disease rating scale, the modified Hoehn and Yahr staging scale and NMS burden for attention/memory. <b><i>Conclusion:</i></b> Our findings support the hypothesis that subjects with low serum UA levels may be more prone to developing PD and indicate that the inverse relationship between UA and severity of PD was robust for men but weak for women. Our results strongly imply that either low serum UA level is a deteriorative predictor or that serum UA level serves as an indirect biomarker of prediction in PD but not in VP patients.