Serum γ-glutamyltransferase as an independent predictor for incident type 2 diabetes in middle-aged and older adults: Findings from the KoGES over 12 years of follow-up

Backgrounds and aims: Limited evidence is available on whether serum gamma-glutamyltransferase (GGT) has value as a predictor of type 2 diabetes in East Asian populations. We investigated the causal relationship between serum GGT level and incident type 2 diabetes in Korean adults. Methods and results: A total of 7739 nondiabetic adults aged 40-69 years from the Korean Genome and Epidemiology Study were studied. We divided the population into four groups according to sex-specific quartiles by serum GGT levels. Hazard ratios (HRs) with 95% Confidence intervals (CIs) for incident type 2 diabetes were prospectively analyzed using multivariate Cox proportional hazards regression models. A total of 1432 (18.5%) participants developed type 2 diabetes over 12 years of follow-up. The higher the serum GGT group quartile, the higher the cumulative type 2 diabetes incidence over 12 years with significance in both sexes (log-rank test P < 0.001). HRs (95% CIs) for incident type 2 diabetes for the highest quartile versus referent lowest quartile for serum GGT levels were 2.55 (1.86-3.51) for men and 1.90 (1.40-2.58) for women after adjusting for confounding variables. Conclusions: Higher serum GGT levels preceded and positively associated with incident type 2 diabetes among community-dwelling middle-aged and older Korean adults. (C) 2020 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.