Using the triglyceride-glucose index and derived indexes to forecast progression from pre-diabetes to diabetes: A...

Pre-diabetes is a transitional metabolic stage between health and diabetes, serving as a critical warning signal for disease progression. Early intervention targeting risk factors in prediabetic individuals prevents the progression to type 2 diabetes.

To investigate the predictive value of the triglyceride-glucose (TyG) index and its derived indicators for new-onset diabetes in patients with pre-diabetes.

A prospective community-based cohort study was carried out based on subjects aged over 40 years with pre-diabetes in Dalian, Liaoning Province, China. A total of 1352 subjects with complete follow-up data attended the follow-up survey. Multivariable Cox regression models were performed to assess the association of the TyG index and its derived indicators with risk of diabetes in patients with pre-diabetes. The diagnostic values of the TyG index and derived indicators in predicting new-onset diabetes were analyzed, and suitable cutting points were determined using the receiver operating characteristic (ROC) curve.

During a 3-year follow-up period, 153 cases with incident diabetes were identified, with a cumulative incidence of diabetes of 11.3%; 12.6% (43/341) in males and 10.9% (110/1011) in females (χ ² = 0.760, P = 0.375). After adjusting for confounding factors including age, gender, body mass index (BMI) and insulin levels, the risk of diabetes with higher TyG and derived indexes [TyG-BMI and TyG-waist circumference index (TyG-WC)] increased significantly. The TyG index [hazard ratio (HR) = 1.389, 95% confidence interval (CI): 1.011-1.908, P = 0.043], TyG-BMI (HR = 1.010, 95%CI: 1.005-1.015, P = 0.000) and TyG-WC (HR = 1.003, 95%CI: 1.001-1.005, P = 0.001) were all strongly positively correlated with the risk of future diabetes. The ROC curve analysis showed that the area under the curve (AUCs) of the TyG, TyG-BMI and TyG-WC for predicting new diabetes were 0.578 (95%CI: 0.533-0.624), 0.622 (95%CI: 0.574-0.670) and 0.609 (95%CI: 0.562-0.657), respectively. The difference in AUC between TyG-BMI and TyG was significant (P = 0.047), while the differences between TyG-BMI and TyG-WC (P = 0.464) and between TyG-WC and TyG (P = 0.175) were not. The TyG-BMI had a larger AUC than the TyG and TyG-WC, and its difference from TyG was significant. The best cut-off points for predicting new diabetes were TyG > 8.6, TyG-BMI > 247 and TyG-WC > 860. Although the AUC values were modest, these indices may serve as preliminary screening tools in resource-limited settings.

The TyG index and its derived indicators were risk factors for the pre-diabetes to diabetes outcome, and may be regarded as predictors of the outcome. The risk of conversion of pre-diabetes to diabetes increased with increases in the TyG index and its derived indicators. The TyG-BMI was better than TyG and TyG-WC in predicting the 3-year outcome for diabetes. Although these indices could aid in the initial risk stratification in primary care, their modest accuracy warrants cautious interpretation.