Association between the functional polymorphism of catechol-O-methyltransferase gene and alcohol consumption among social drinkers

Background: A common functional gene tic polymorphism in the catechol-O-met hyltransferase (COMT) gene (Val158 Met) results in 3- to 4-fold differences in COMT enzyme activity and dopamine inactivation rate. Previous studies h ave shown that type I alcoholism is more common among subjects with low act ivity COMT genotype (LL), compared with high activity (HH) or heterozygotic (LH) genotypes. Methods: We studied alcohol consumption and the COMT genotype in middle-age d Finnish men (n = 896), who represented an unselected ethnically homogenou s population sample and reported using alcohol during the past year. Averag e alcohol use in pure ethanol (grams per week) was compared between subject s with LL genotype and subjects with LH or HH genotypes. Results: Men with LL genotype (30% of all subjects) reported 27% higher wee kly alcohol consumption compared with the two other genotype groups (p < 0. 05). The difference remained statistically significant after a multivariate adjustment for sociodemographic factors and prior or existing diseases (p = 0.031). Conclusions: The results indicate that COMT polymorphism may contribute sig nificantly to alcohol intake not only in alcoholics but also in a general m ale population.