Background/aims: A complex interaction of host genetic and environmental factors may be relevant in the development of Helocobacter pylori (H. pylori) related gastroduodenal diseases. Catechol-O-methyltransferase (COMT) is expressed catalyzes the methylation of various endobiotic and xenobiotic substances and thus might protect DNA from oxidative damage. We aimed to clarify the effect of COMT functional polymorphism on the severity of histological gastritis in a Japanese population.
Methodology: 203 subjects were included in this study. Restriction fragment length polymorphism analysis was performed for polymorphisms at codon 158 in the COMT gene. Gastritis scores of antral gastric mucosa were assessed according to the updated Sydney system.
Results: COMT genotype distribution in the study subjects was 158Val/Val (51.2%), 84Val/Met (41.4%), and 15Met/Met (7.4%). It was within the Hardy-Weinberg equilibrium (p = 0.73). In over all subjects, the degree of intestinal metaplasia tended to be lower among 158Met/Met when compared to Val/Val (Val/Val vs. Met/Met; 0.59 +/- 0.93 vs. 0.13 +/- 0.52, p = 0.052). Among H. pylori infected subjects, the degree of intestinal metaplasia was significantly lower among 158Met carriers in 50 years or older age (Val/Val vs. Met carriers; 1.20 +/- 1.06 vs. 0.75 +/- 1.08, p = 0.0436). No significant association was found between COMT genotypes and the degree of gastritis in different gender
Conclusion: Our data suggest that COMT gene 158Met polymorphism is associate with a reduced risk of developing more severe intestinal metaplasia in H. pylori infected older subjects.