ABSTRACT

Parkinson's disease (PD) is a common neurodegenerative disease, the risk factors of which are gaining more attentions. Among all these risk factors, catechol-o-methyltransferase (COMT) has been widely studied, and believed to be associated with PD. However, the relationship between COMT polymorphism and PD has not been confirmed hitherto. Therefore, a meta-analysis was performed to evaluate the effect of COMT polymorphism on PD patients. A total of 24 study subjects comprising 3,807 patients with PD and 3,942 unrelated healthy controls were recruited in this meta-analysis. Heterogeneity testing and sensitivity analysis were conducted with Review Manager 5.0 software (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark) and Stata software (StataCorp, College Station, TX), together with publication bias by funnel plot method and modified Egger's linear regression test. No evidences of publication bias and heterogeneity were detected. In the 24 studies, the estimated odds ratios (OR) in PD patients are 0.98 for the Met allele (95% confidence interval [0.92, 1.05]) under a fixed-effects model. The authors also conducted a stratified analysis according to geographic region among Europe, Asia, and North America, the ORs for the Met allele are 0.92, 1.02, and 1.10, respectively. According to the results of the meta-analysis, a conclusion could be drawn that polymorphism of Val108/158Met are not associated with the risk of PD. However, more convincing studies are warranted to have a solid conclusion supported.