Associations between alcohol consumption and type 2 diabetes risk are inconsistent in epidemiologic studies. This study investigated the associations of ADH1B and ALDH2 polymorphisms with fasting blood glucose levels, and the impact of the associations of alcohol consumption with fasting blood glucose levels in Japanese individuals. This cross-sectional study included 907 men and 912 women, aged 35–69 years. The subjects were selected from among the Japan Multi-institutional Collaborative Cohort study across six areas of Japan. The ADH1B and ALDH2 polymorphisms were genotyped by Invader Assays. The ALDH2 Glu504Lys genotypes were associated with different levels of fasting blood glucose in men (P = 0.04). Mean fasting glucose level was positively associated with alcohol consumption in men with the ALDH2 504 Lys allele (Ptrend = 0.02), but not in men with the ALDH2 504Glu/Glu genotype (Ptrend = 0.45), resulting in no statistically significant interaction (P = 0.38). Alcohol consumption was associated with elevated fasting blood glucose levels compared with non-consumers in men (Ptrend = 0.002). The ADH1B Arg48His polymorphism was not associated with FBG levels overall or after stratification for alcohol consumption. These findings suggest that the ALDH2 polymorphism is associated with different levels of fasting blood glucose through alcohol consumption in Japanese men. The interaction of ALDH2 polymorphisms in the association between alcohol consumption and fasting blood glucose warrants further investigation.
