Association between gamma-glutamyltransferase levels and insulin resistance according to alcohol consumption and number of cigarettes smoked

Aim: alcohol intake may increase serum gamma-glutamyltransferase (ggt) but reduce insulin resistance. we analyzed the association between ggt and a marker of insulin resistance,homeostasis model assessment for insulin resistance (homa-ir),according to the drinking and smoking status. methods: after excluding former smokers and/or former drinkers,the data of 10,482 men who underwent general health screening were analyzed. results: alcohol consumption showed a graded association with ggt. in men with current alcohol consumption of ≥40 g per day,≥20 cigarettes per day further increased ggt levels. alcohol consumption showed a u-shaped association with homa-ir. in contrast,smoking 20-39 and ≥40 cigarettes per day increased homa-ir as compared with never smokers. an interaction between alcohol consumption and smoking was present for ggt (p<0.001) and homa-ir (p=0.059). ggt was not a significant negative predictive value for homa-ir regardless of the drinking or smoking status. conclusions: although alcohol intake showed a graded association with ggt and a u-shaped association with homa-ir,serum ggt can be utilized as a predictor of insulin resistance in current drinkers.