The triglyceride high-density cholesterol-glucose body index as a superior metabolic biomarker for incident type 2 diabetes in normoglycemic subjects: a large-scale cohort study

Background The triglyceride high-density cholesterol-glucose body index (TyHGB) is a novel composite metabolic index, but evidence regarding its association with incident type 2 diabetes mellitus (T2DM) and predictive performance is lacking. Methods This was a retrospective cohort study based on a secondary analysis of publicly available data from the NAGALA (NAfld in the Gifu Area, Longitudinal Analysis) study. This study cohort included 15,453 participants with normoglycemia at baseline. Cox proportional hazards regression was used to evaluate the association between TyHGB and incident T2DM. Restricted cubic splines and threshold effect analyses were performed to explore nonlinear relationships. Time-dependent receiver operating characteristic (ROC) curves were used to assess the predictive performance of TyHGB. Results Over a median follow-up of 5.4 years, 373 participants developed T2DM. After multivariable adjustment, each unit increase in TyHGB was associated with a 36% higher risk of T2DM (hazard ratio [HR] = 1.36, 95% confidence interval [CI]: 1.27 – 1.45). Compared with the lowest quartile, the highest quartile had a 5.68-fold risk (HR = 5.68, 95% CI: 2.84 – 11.36). A nonlinear relationship was identified, with an inflection point at TyHGB = 6.748. Time-dependent ROC analysis showed that TyHGB consistently demonstrated the highest area under the curve (AUC) for predicting incident diabetes at 3, 5, and 10 years of follow-up compared with traditional indices. Conclusions TyHGB is an independent risk factor for incident T2DM with a threshold effect. It demonstrates superior long-term predictive ability compared with traditional indices and may serve as a simple, cost-effective tool for diabetes risk stratification in large-scale community screening and primary care, particularly in resource-limited settings.