Heritabilities of Alcohol Use Disorders Identification Test (AUDIT) scores and alcohol biomarkers in Koreans: The KoGES (Korean Genome Epi Study) and Healthy Twin Study

Background: Both the Alcohol Use Disorders Identification Test (AUDIT) and alcohol biomarkers are used to screen for alcohol problems. The purpose of this study was to examine the genetic and environmental contributions to the AUDIT score and alcohol biomarkers in Koreans. Methods: The study included 1678 current alcohol drinkers: 818 Korean twins and 860 their families. The Korean version of AUDIT and alcohol biomarkers, i.e., gamma glutamyltransferase (GGT), alanine aminotransferase (ALT), mean corpuscular volume (MCV), and triglycerides (TG), were studied. The analyses were conducted using variance components method to estimate heritability and common environmental effects, and bivariate analyses for genetic and environmental correlations between the AUDIT score and the biomarkers after adjustment for age, gender, interaction of age and gender, smoking status, the amount of consumed alcohol, body mass index, and education. Results: Heritabilities for the AUDIT score were 0.35 and 0.40-0.71 for biomarkers (P<0.001). The risk of alcohol problems using AUDIT score was positively associated with the levels of biomarkers (GGT, MCV, and TG) in men, while the relationship was significant only for MCV in women. Genetic or environmental correlations between the AUDIT score and some of the biomarkers (GGT and MCV) were significant in men, but not significant in women. Conclusions: We found a significant genetic contribution to the AUDIT score and the alcohol biomarkers. As there were significant genetic and environmental relationships between the AUDIT score and the alcohol biomarkers in men, future studies are warranted to identify common genes and environmental effects affecting the relationships. (C) 2010 Elsevier Ireland Ltd. All rights reserved.