Clinical association between serum γ‐glutamyltransferase levels and the development of insulin resistance in Korean men: a 5‐year follow‐up study

Abstract

Aims In recent years, γ‐glutamyltransferase has emerged as a predictor of cardiovascular disease, Type 2 diabetes mellitus, the metabolic syndrome and hypertension. However, it is not yet certain whether γ‐glutamyltransferase is a predictor for insulin resistance. The aim of this study was to examine the longitudinal association between baseline γ‐glutamyltransferase level and the development of insulin resistance in Korean men. Methods We performed a prospective cohort study, involving 22 931 healthy Korean men without baseline insulin resistance (homeostasis model assessment of insulin resistance, HOMA‐IR < 2.7) for 5 years. We checked the HOMA‐IR serially to monitor the development of insulin resistance (incidence of HOMA‐IR ≥ 2.7). A Cox proportional hazards model was used to determine hazard ratios for insulin resistance by quartile groups of baseline serum γ‐glutamyltransferase levels. Results During 81 208.6 person‐years of follow‐up, 3856 (16.8%) cases of insulin resistance developed between 2006 and 2010. After adjusting for multiple covariates, including baseline HOMA‐IR, the hazard ratios (95% CI) for incident insulin resistance comparing the second to the fourth quartile of baseline serum γ‐glutamyltransferase levels with the first quartile were 1.19 (1.06–1.33), 1.38 (1.23‐1.53) and 1.58 (1.41‐1.77), respectively (P for trend < 0.001). Conclusions Our findings show that serum γ‐glutamyltransferase level could be a predictor of the development of insulin resistance in Korean men.