Relationship between response of γ-glutamyltransferase to alcohol consumption and levels of fasting plasma glucose

To examine whether the response of fasting plasma glucose (FPG) to alcohol consumption differs among individuals, a cross-sectional study was conducted in 6100 men with a body-mass index below 24 who did not take medication for diabetes. Information regarding current medication and lifestyle habits was obtained by a self-reported questionnaire. The subjects were divided into four groups according to their level of alcohol consumption: non-drinkers, light drinkers (1–188 ml/week), intermediate drinkers (189–377 ml/week), and heavy drinkers (≧378 ml/week). The frequency of subjects with an FPG of 110 mg/dl or more rose significantly as alcohol consumption increased, from 6.7% in non-drinkers to 10.1% in intermediate drinkers and 12.1% in heavy drinkers. In contrast, when only the subjects with a γ-glutamyltransferase level of less than 40 IU/L were analyzed, no difference was observed in the frequency of subjects with an FPG level of 110 mg/dl or more among the four groups. Multiple logistic regression analysis also revealed similar results. The findings suggested individual variability in the response of FPG to drinking. Appropriate levels of drinking could be different among individuals.