Triglyceride–glucose–alanine aminotransferase index: A noninvasive serum predictor for identifying the severity of pediatric nonalcoholic fatty liver disease

Abstract

We hypothesized that the triglyceride–glucose (TyG)–alanine aminotransferase (ALT) index, which combines the TyG index with ALT, may enhance sensitivity and specificity in detecting the severity of nonalcoholic fatty liver disease (NAFLD). A total of 131 NAFLD patients with a mean age of 11.5 ± 2.29 years were enrolled, and severity was assessed by ultrasound fatty liver index (US-FLI) scoring. The TyG–ALT index was defined as ln(fasting triglyceride [mg/dL] × fasting glucose [mg/dL] × ALT [IU/L]/2). Multiple linear regression analysis revealed a significant association between the TyG–ALT index and US-FLI (β = 0.317, P < .001) after controlling for sex, age, and body mass index. The TyG–ALT index showed a more stable and superior ability to detect the severity of NAFLD compared to both ALT and the TyG index. The area under the curve values, listed in the order of ALT, TyG index, and TyG–ALT index, were as follows: 0.737 (P < .001), 0.599 (P = .055), and 0.704 (P < .001) at US-FLI ≥ 4 points; 0.717 (P < .001), 0.720 (P < .001), and 0.775 (P < .001) at US-FLI ≥ 5 points; and 0.689 (P < .05), 0.748 (P < .01), and 0.775 (P < .001) at US-FLI ≥ 6 points. The TyG–ALT index is associated with US-FLI score and superior to both ALT and the TyG index in predicting NAFLD severity. These findings indicate the potential of the TyG–ALT index in the management of pediatric NAFLD progression.