Sex-dependent association of urate on the patterns of striatal dopamine depletion in Parkinson's disease.

BACKGROUND AND PURPOSE

The aim was to investigate the relationship between the serum urate (UA) levels and patterns of striatal dopamine depletion in patients with de novo Parkinson's disease (PD).

METHODS

In all, 167 de novo PD patients who underwent F-fluorinated N-3-fluoropropyl-2-beta-carboxymethoxy-3-beta-(4-iodophenyl) nortropane positron emission tomography scans were enrolled. After quantifying dopamine transporter (DAT) availability in each striatal subregion, sex-dependent patterns of striatal dopamine depletion were analysed by measuring (i) dopamine depletion in the other striatal subregions and posterior putamen (intersubregional ratio, ISR) and (ii) the interhemispheric asymmetry of dopamine depletion in the posterior putamen (asymmetric ratio, AR).

RESULTS

The interaction analysis revealed a significant interaction effect of sex and serum UA levels on the ISR but not on the AR. The ISR was negatively correlated with the serum UA levels in all patients with PD (r = -0.156, P = 0.045), and this association was more prominent in male PD patients (r = -0.422, P < 0.001). However, no significant association between the AR and serum UA levels was found in any of the patients. In addition, serum UA levels were significantly associated with DAT availability in the posterior putamen on both the more affected side (r = 0.312, P = 0.005) and the less affected side (r = 0.312, P = 0.005) only in male PD patients.

CONCLUSIONS

The present study demonstrated the potentially close sex-specific relationship between the serum UA levels and the anterior-posterior gradient of DAT patterns, suggesting a sex-specific protective effect of UA on nigrostriatal dopaminergic neurons in de novo PD.