Abstract
Objective: To investigate the association between a polymorphism related to dopamine receptors, known as Taq1A, and smoking behavior in a Brazilian population sample. Methods: This is a cross-sectional study, with 449 individuals of both sexes, over 18 years old.The history of smoking behavior was obtained through a questionnaire. Blood samples were genotyped for TaqIA (rs1800497) by real-time Polymerase Chain Reaction (qPCR). Logistic and linear regression analyzes were used to verify the effect of genotypes on smoking behavior. Results: 66.4% of participants were Never smokers, 12.2% were Current smokers and 21.4% were Ex-smokers. The variant T allele of TaqIA was associated with later smoking initiation compared to CC (16.97 vs. 15.09; 95% CI: 15.75-18.19; p = 0.02). The T allele also conferred a higher probability of cessation in women (OR = 3.17; 95% CI: 1.06-9.45; p = 0.04). No significant difference was found in men. No association was observed between the polymorphism and the risk of becoming a smoker, CPD, and FTND. Conclusion: TaqIA rs1800497 was associated with a protective effect for the age of initiation of smoking and a higher probability of cessation in women, in a Brazilian population sample.