Association of catechol-O-methyltransferase with smoking cessation in two independent studies of women.

Objectives and methods The Val108/158Met polymorphism in the gene that encodes COMT, a dopamine metabolizing enzyme, results in a three- to four-fold reduction in COMT activity. To determine if the lower activity Met allele of COMT was associated with smoking cessation in women, we used two independent studies: a population-based case-control study and a nicotine replacement clinical trial. Results In the case-control study, women with two Met alleles were significantly more likely to be ex-smokers than current smokers [OR =1.82, 95% Cl (1.05, 3.17), P=0.03]. In the nicotine replacement clinical trial, among women, the Met/Met genotype was associated with a higher probability of smoking cessation based on both point prevalence and prolonged abstinence outcomes [OR = 2.96, 95% Cl (1.07, 8.14), P=0.04; OR = 3.23, 95% Cl (1.13, 9.20), P=0.03, respectively]. Conclusions This first report of a significant association between COMT Val108/158Met and smoking cessation suggests that COMT variation has an effect on smoking behavior in women.