Elevated Liver Function Enzymes Are Related to the Development of Prediabetes and Type 2 Diabetes in Younger Adults The Bogalusa Heart Study

OBJECTIVE-Elevations in alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT), surrogate markers of liver dysfunction and nonalcoholic fatty liver, are considered as part of metabolic syndrome and related type 2 diabetes. However, information is limited regarding the long-term predictability of ALT and GGT in the development of prediabetes and type 2 diabetes. RESEARCH DESIGN AND METHODS-In this retrospective cohort study, normoglycemic (n = 874), prediabetic (n = 101), and diabetic (n = 80) adults aged 26-50 years (average age 41.3 years) were followed over an average period of 16 years since their young adulthood (aged 18-38 years, average age 25.1 years), with measurements of cardiometabolic risk factor variables including ALT and GGT. RESULTS-The follow-up prevalence rate of adult diabetes status by quartiles of baseline ALT and GGT levels showed an adverse trend for both prediabetes (P < 0.05) and diabetes (P < 0.01). In a longitudinal multivariate logistic regression analysis that included anthropometric, hemodynamic, and metabolic variables, as well as alcohol consumption and smoking, individuals with elevated baseline ALT and GGT levels (per 1-SD increment) were 1.16 and 1.20 times, respectively, more likely to develop diabetes (P = 0.05 for ALT and P < 0.01 for GGT); no such associations were noted for prediabetes. Regarding the predictive value of ALT and GGT, the area under the receiver operating curve analysis yielded C values ranging from 0.70 to 0.82, with values significantly higher for diabetes compared with prediabetes. CONCLUSIONS-These findings in younger adults suggest potential clinical utility of including ALT and GGT as biomarkers in diabetes risk assessment formulations. Diabetes Care 34:2603-2607,2011