Background: Recent research in adults has shown fasting intact insulin levels measured by mass spectrometry can predict nonalcoholic fatty liver disease (NAFLD) in patients without diabetes; however, there is limited research in children. This study aimed to evaluate fasting intact insulin by LC-MS/MS as a predictive biomarker of NAFLD in adolescents.

Methods: This retrospective, cross-sectional study was based on data from four previously conducted studies. Existing clinical laboratory values included fasting intact insulin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), C-peptide, and the insulin resistance (IR) score. Hepatic fat was assessed by magnetic resonance imaging proton density fat fraction (MRI-PDFF) or MR spectroscopy (MRS). NAFLD was defined as intrahepatic fat of ≥5%.

Results: A total of 73 children were included in the analysis (64% male; 13.9 ± 2.8 years of age; body mass index (BMI) 29.1 ± 8.5 kg/m2; 56% with NAFLD). Intact fasting insulin, C-peptide, AST, ALT, and IR scores were higher in children with NAFLD compared to non-NAFLD children (P<0.05). Fasting intact insulin measurements predicted NAFLD (area under the receiver operating characteristic curve [AUROC] of 0.83 [95%CI, 0.73-0.93]). When combined with ALT (intact insulin (μU/mL) × ALT (× U/L)), the combined biomarker slightly improved the prediction of NAFLD (AUROC 0.89 [0.81-0.96]), with positive and negative predictive values of 79% and 100%, respectively. Based on maximizing Youden's index, the optimal cutoff points to predict NAFLD were 13.0 μU/mL for intact insulin and 380 μU/mL × U/L for intact insulin × ALT.

Conclusion: Our findings support that fasting intact insulin alone, or combined with ALT (intact insulin × ALT), show promise as predictive biomarkers for pediatric NAFLD with high positive and negative predictive values. Additional studies are needed to validate these findings in other pediatric populations.

Disclosure

H. Huneault: None. D. Ayinde: None. Z. He: None. C. C. Cohen: None. M. J. McPhaul: Employee; Quest Diagnostics. M. B. Vos: Consultant; Boehringer Ingelheim International GmbH, BMS, Intercept Pharmaceuticals, Inc., Novo Nordisk, ProSciento, Eli Lilly and Company. Research Support; Quest Diagnostics, TARGET PharmaSolutions, Inc.

Funding

National Institutes of Health (R01DK125701); Georgia Clinical Translational Science Alliance (UL1TR002378)

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