A recent meta-analysis of genome-wide association studies data from East Asians identified acetaldehyde dehydrogenase 2 (ALDH2) rs671 as a susceptibility variant for type 2 diabetes in males.We studied 94 non-obese, non-diabetic, Japanese men. Using a two-step hyperinsulinemic-euglycemic clamp, we evaluated insulin sensitivity in muscle and liver. Intrahepatic lipid and fat distribution were measured using 1H-magnetic resonance spectroscopy and magnetic resonance imaging, respectively. We divided the subjects into risk carrying group with ALDH2 rs671 G/G (n=53) and non-risk carrying group with ALDH2 rs671 G/A or A/A (n=41).The risk carrying group had significantly higher levels of alcohol consumption (18.4 (IQR, 10.4-48.9) vs. 12.1(IQR, 1.3-29.0) g/day; P=0.003), elevated fasting plasma glucose (FPG) (97.5±7.9 vs. 93.5±6.2 mg/dL; P=0.010), lower hepatic insulin sensitivity (61.7±20.5% vs.73.1±15.9%; P=0.003) and lower fasting glucose clearance (0.84±0.8 dL·m -2·min -1 vs. 0.87±0.09 dL·m -2·min -1; P=0.047) than the non-risk carrying group, while insulin resistance in muscle and body fat distribution were similar. The single linear correlation analysis revealed significant correlations between alcohol consumption and hepatic insulin sensitivity (r=-0.262, P=0.011), fasting glucose clearance (r=-0.370, P<0.001) or FPG (r=0.489, P<0.001). The multiple regression analysis revealed that both ALDH2 rs671 G/G genotype and alcohol consumption were significant independent correlates for hepatic insulin sensitivity, while only alcohol consumption was a significant independent correlate for fasting glucose clearance.Our data suggested that high-alcohol-intake dependent and independent hepatic insulin resistance and reduced fasting glucose clearance due to high alcohol intake could be a relatively upstream metabolic abnormality in ALDH2 rs671 G/G carriers.
Kageumi Takeno, Yoshifumi Tamura, Saori Kakehi, Hideyoshi Kaga, Ryuzo Kawamori, Hirotaka Watada