Aim: Catechol-O-methyltransferase (COMT) is one of the major degradative pathways of dopamine and COMT Val/Met polymorphisms are associated with the enzyme activity, which is related to dopamine involvement in the nicotine addiction process. However, the reported results of several genetic studies are not consistent.
Materials & methods: We reviewed the smoking cessation outcomes among previously reported studies by comparing COMT polymorphism. A total of five studies were assessed in the present meta-analysis and the Met/Met, Val/Met or Val/Val genotype were compared with respect to smoking cessation outcomes.
Results: As the results, any significant association between COMT polymorphism and smoking cessation were not observed. In the subgroup analysis for evaluating the association between COMT polymorphism and smoking cessation therapy, three studies were assessed by comparing two groups (Met/Met vs Val/Met plus Val/Val). A significant association between COMT polymorphism and smoking cessation was observed (odds ratio: 1.871 and 95% CI: 1.382-2.534).
Conclusion: The COMT polymorphisms are associated with the outcomes following smoking cessation treatment with nicotine.
Keywords: COMT; gene polymorphism; meta-analysis; smoking cessation.