Serum gamma-glutamyltransferase levels and the risks of impaired fasting glucose in healthy men: a 2-year follow-up

An increase in the serum gamma-glutamyltransferase (GGT) concentration has been regarded as a marker of alcohol drinking or liver disease. Some reports, however, have suggested that the serum GGT may be a sensitive and early biomarker for the development of prediabetes and diabetes. In this study we investigated whether serum GGT is a reliable predictor of the incident impaired fasting glucose (IFG), including diabetes. We performed a prospective study for two years (2002-2004). We analyzed the periodic health examination data from a total of 4,711 men. The examinations were done in the years 2002 and 2004. The analyzed data included a self-questionnaire, a physical examination and the laboratory results. Both IFG and diabetes were defined as a serum fasting glucose concentration of more than 100 mg/dL and 126 mg/dL, respectively. A total of 738 cases (15.7%) of incident IFG and 13 cases (0.3%) of diabetes occurred. The mean serum GGT concentrations were quite different between the normal (38.0 IU) and incident IFG groups (50.3 IU), and the incident diabetes group (66.0 IU) (p