Lack of association between DRD2 Taq1A gene polymorphism and smoking cessation therapy: a meta-analysis.

Recent studies have reported that genetic factors are significantly associated with smoking behavior, but the influence of the smoking behavior-related genes on smoking cessation treatment is still not clear. We analyzed the smoking cessation outcomes among previously reported studies involving participants who underwent smoking cessation therapy by comparing the following DRD2 Taq1A gene polymorphism using meta-analysis. In total, nine studies including 2,851 participants were assessed and the A1 allele carriers and A2 homozygotes were compared with respect to smoking cessation outcomes by meta-analysis. No significant association was observed for the main analysis (OR = 0.900; 95% CI, 0.751 - 1.078). In subgroup analysis, three studies were assessed by comparing participants with the A1/A1, A1/A2, and A2/A2 genotypes. A significant association between the DRD2 Taq1A polymorphism and< smoking cessation therapy was observed between the A1/A1 and A1/A2 genotypes (OR = 2.967; 95% CI 1.737 - 5.068) and between the A1/A2 and A2/A2 genotypes (OR = 0.547; 95% CI 0.392 - 0.762), but not between the A1/A1 and A2/A2 genotypes (OR = 1.269; 95% CI 0.746 - 2.157). This study is the first meta-analysis to evaluate and quantitatively integrate the association between the DRD2 Taq1A polymorphism and smoking cessation therapy. A significant relationship between DRD2 Taq1A polymorphism and smoking cessation therapy was not observed.