Triglyceride–glucose index (TyG index) in comparison with fasting plasma glucose improved diabetes prediction in patients with normal fasting glucose: The Vascular-Metabolic CUN cohort

•TyG index was useful for the early identification of patients at risk of diabetes.•Triglyceride levels upper than 86 mg/dl were a risk factor for developing diabetes.•A glucose level greater than 96 mg/dl significantly increased diabetes risk.•TyG index was the best predictor of developing diabetes in normoglycemic patients.•More attention should be given to high triglyceride levels and diabetes risk.

AimsWe evaluated the potential role of the triglyceride–glucose index (TyG index) as a predictor of diabetes in a White European cohort, and compared it to fasting plasma glucose (FPG) and triglycerides.Methods4820 patients of the Vascular-Metabolic CUN cohort (VMCUN cohort) were examined and followed up for 8.84 years (± 4.39). We performed a Cox proportional hazard ratio with repeated-measures analyses to assess the risk of developing type 2 diabetes across quartiles of FPG, triglycerides and the TyG index (ln[fasting triglycerides (mg/dl) × fasting plasma glucose (mg/dl)/2]), and plotted a receiver operating characteristics (ROC) curve for discrimination.ResultsThere were 332 incident cases of type 2 diabetes involving 43,197.32 person-years of follow-up. We observed a progressively increased risk of diabetes in subjects with TyG index levels of 8.31 or more. Among those with normal fasting glucose at baseline, < 100 mg/dl, subjects with the TyG index in the fourth quartile were 6.87 times more likely to develop diabetes (95% CI, 2.76–16.85; P for trend < 0.001), as compared with the bottom quartile. The areas under the ROC curves (95% CI) were 0.75 (0.70–0.81) for TyG index, 0.66 (0.60–0.72) for FPG and 0.71 (0.65–0.77) for TG, in subjects with normal fasting glucose (p = 0.017).ConclusionsOur data suggest that the TyG index is useful for the early identification of individuals at risk of type 2 diabetes. The TyG index seems to be a better predictor than FPG or triglycerides of the potential development of type 2 diabetes in normoglycemic patients.