The Effect of Gamma-Glutamyltransferase on Impaired Fasting Glucose or Type 2 Diabetes in Korean Men

Abstract

Background: We sought to determine the association between serum gamma-glutamyltransferase (GGT) levels within the normal range and the risk for development of impaired fasting glucose (IFG) or type 2 diabetes. Methods: This retrospective cohort study spanned four years (2002~2006) with 1,717 Korean men who underwent periodic health examinations at a university hospital in Incheon, Korea and were not diagnosed with IFG or type 2 diabetes. Fasting plasma glucose levels were measured at the annual health examination. IFG and diabetes were defined as a serum fasting glucose concentration of 100~125 mg/dL and more than 126 mg/dL, respectively. Cox's proportional hazards model was used to evaluate the association between serum GGT levels and development of IFG or type 2 diabetes. Results: There was a strong dose-response relationship between serum GG T levels and the incidence of IFG and diabetes. A total of 570 cases (33.2%) of incident IFG and 50 cases (2.9%) of diabetes were found. After controlling potential predictors, the relative risks for the incidence of IFG for GGT levels ≤ 19, 20~25, 26~34, 35~50 and ≥ 51 were 1.00, 0.99, 1.17, 1.23 and 1.38 respectively (P for trend 0.015), and for the incidence of diabetes were 1.00, 1.44, 1.80, 2.55 and 2.58 respectively (P for trend 0.050). Conclusion: The risk for development of IFG and type 2 diabetes increased in a dose-dependent manner as serum GGT increased within its normal range in Korean men. (Korean Diabetes J 33:215-224, 2009)