Association of the ADH2 genotypes with skin responses after ethanol exposure in Japanese male university students.

BACKGROUND

A contribution of the alcohol dehydrogenase-2 (ADH2) polymorphism to alcohol sensitivity and alcohol drinking behavior is still controversial. In this study, we examined the effects of the ADH2 genotypes on skin reactions to ethanol and habitual alcohol intake among Japanese male university students, controlling for the effects of the low Km aldehyde dehydrogenase (ALDH2) genotype, as an extension of our previous study.

METHODS

The study subjects were 357 Japanese male students [average age (mean +/- SD) was 23.7 +/- 3.0 years] in a medical university. The subjects completed a questionnaire regarding self-reported alcohol-associated symptoms and alcohol-drinking behavior. The ADH2 and ALDH2 genotypes were determined through digestion of polymerase chain reaction products by restriction enzymes. All subjects participated in the ethanol patch test. We observed skin responses at 0, 5, 15, and 20 min after removal of the tape.

RESULTS

Among the ALDH2*1/1 genotypes, only some subjects with ADH21/2 or ADH22/2 exhibited a positive response, which increased with increasing time after the removal. However, none of comparisons between the different ADH2 genotypes reached statistical significance. Among the ALDH21/2 genotypes, those with ADH21/2 or ADH22/2 showed a significant increase in response with increasing time after the removal and revealed a significantly higher positivity rate at 15 min than those with ADH21/1. In those with the ALDH21/2 genotype, the positive rate of facial flushing with one glass of beer was higher in those with ADH21/2 and ADH22/2 than those with ADH21/*1, although this was not significant. However, the ADH2 genotype did not seem to influence drinking frequency or amounts of alcohol intake in each ALDH2 genotype.

CONCLUSIONS

This study finds further evidence for a contribution of the ADH2 polymorphism to skin reactions after either local or systemic ethanol exposure in Asian people. However, the effects of the ADH2 polymorphism may be mild because this polymorphism does not seem to influence alcohol drinking behavior in these study subjects.