The triglyceride-glucose index, a predictor of type 2 diabetes development: A retrospective cohort study

Aims The triglycerides-glucose (TyG) index, the product of fasting plasma glucose (FPG) and triglycerides (TG) is a novel index. Many previous studies have reported that the TyG index might be a strong predictor of incident type 2 diabetes. We determined whether the TyG index could be a useful predictor for diabetes diagnosis and compared it to the FPG and TG as predictors of type 2 diabetes. Methods A total of 617 subjects without baseline diabetes were examined and followed up for a median period of 9.2 years. We performed a mixed effect cox regression analysis to evaluate the risk of developing diabetes across the quartiles of the TyG index, calculated as ln[triglyceride (mg/dl) × FPG (mg/dl)/2], and plotted a receiver operating characteristic (ROC) curve to assess discrimination among TyG, FPG and TG. Results During 4,871.56 person-years of follow-up, there were 163 incident cases of diabetes. The risk of diabetes increased across the quartiles of the TyG index. Those in the highest quartile of TyG had a higher risk of developing diabetes (adjusted HR 3.38 95% CI 2.38–4.8, ptrend < 0.001) than those in the lowest quartile. The area under the curve (AUC) of the ROC plots were 0.79 (95% CI 0.74–0.83) for FPG, 0.64 (95% CI 0.60–0.69) for TyG and 0.59 (95% CI 0.54–0.64) for TG. Conclusion The TyG index was significantly associated with risk of incident diabetes and could be a valuable biomarker of developing diabetes. However, FPG appeared to be a more robust predictor of diabetes.