Diagnostic Performance of the TyG Index in Detecting Metabolic Syndrome: A Cross-Sectional Study from Western Iran

Metabolic syndrome (MetS) is a prevalent condition characterized by a cluster of metabolic abnormalities, including abdominal obesity, dyslipidemia, hypertension, and impaired glucose metabolism. Early identification and screening are vital for effective management. The triglyceride-glucose (TyG) index, calculated from fasting triglyceride and glucose levels, is gaining recognition as a surrogate marker for insulin resistance and MetS. This study evaluates the TyG index as a standalone predictor of MetS risk and progression.

This cross-sectional analysis used baseline data from the Dehgolan Prospective Cohort Study (DehPCS), which included 3,800 participants aged 35–70 years from western Iran. MetS was defined using World Health Organization (WHO) criteria. The diagnostic performance of the TyG index, its variants, and anthropometric indices was assessed using regression analysis, receiver operating characteristic (ROC) curves, and the area under the curve (AUC).

MetS prevalence in the study population was 35.19%. The TyG-WHtR (waist-to-height ratio) index demonstrated the highest AUC (0.86) in the total population, with sensitivity and specificity of 84.56% and 72.23%, respectively. In males, the TyG-WC (waist circumference) index showed the highest AUC (0.90, sensitivity: 79.29%, specificity: 85.04%). In females, the TyG index alone ranked highest with an AUC of 0.87 (sensitivity: 76.12%, specificity: 87.01%).

The findings indicate that the TyG index combined with anthropometric measures is more effective for MetS diagnosis in the overall and male populations, while the TyG index alone is more valuable for females. These sex-based differences may stem from variations in body fat distribution and metabolic profiles. After adjusting for confounders, the TyG-WHtR remained the most reliable predictor for males and the overall population. The TyG index and its variants offer a reliable and accessible alternative to more complex insulin resistance measures.

The TyG index and its anthropometric variants demonstrated excellent diagnostic performance for MetS, underscoring their value as accessible, cost-effective screening tools—particularly in resource-limited settings. Further research is warranted to validate these findings across diverse populations.