Ability of triglyceride-glucose indices to predict metabolic dysfunction associated with steatotic liver disease in pediatric obesity

Objectives: We aimed to evaluate the best cut-off of alanine aminotransferase (ALT) to predict the metabolic dysfunction-associated steatotic liver disease (MASLD) in youths with overweight/obesity (OW/OB) and analyze the performance of the triglyceride-glucose index (TyG) or its association with anthropometric variables compared to ALT. Methods: This multicenter, cross-sectional study analyzed data of 2813 youths (1463 boys and 1350 girls) aged 6-17 years recruited in 10 Italian centers for the management of pediatric OB. Exclusion criteria were: body mass index (BMI) Z-score >5, diabetes, secondary obesity, triglycerides (TG) >= 400 mg/dL. MASLD was defined on the presence of hepatic steatosis at abdominal ultrasound, in combination with at least one cardiometabolic risk factor. The performance of ALT and TyG-derived indices for MASLD diagnosis was assessed using the receiver operation curve and the area under the curve (AUC) with the 95% confidence intervals were obtained. Results: MASLD was observed in 1278 youths (45.1%). The global AUC of ALT was 0.661 (0.641-0.682), p < 0.0001. Using Youden's index the best cut-off of ALT was >= 26 IU/L in boys and >= 22 IU/L in girls. The AUCs of TyG-BMI, TyG-WC, and TyG-ALT were 0.678 (0.659-0.698), 0.659 (0.639-0.679), and 0.666 (0.645-0.686), respectively. Using Delong's test none TyG-derived index showed a better performance than ALT alone. Conclusions: This study demonstrates that the values of ALT >= 26 IU/L in boys and >= 22 IU/L in girls can be used for the screening of MASLD in youths with OW/OB, while the combination of TyG-derived indices is not superior to ALT alone.