Metabolic and Hepatic Profiles of Non-Obese and Obese Metabolic Dysfunction-Associated Steatotic Liver Disease in Adolescents: The Role of FibroScan Parameters,Fibroblast Growth Factor-21, and Cytokeratin-18.

Background/Aims: Metabolic dysfunction-associated steatotic liver disease (MASLD) in adolescents, including non-obese phenotypes, is an increasingly important public health issue. The current study investigated the use of controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) as non-invasive tools, along with fibroblast growth factor-21 (FGF-21) and cytokeratin-18 (CK-18), in non-obese MASLD, obese MASLD, and healthy control groups, exploring metabolic and hepatic profiles in these groups. Materials and Methods: This cross-sectional study recruited 195 adolescents aged 9-18 years, stratified into controls (n = 92), non-obese MASLD (n = 32), and obese MASLD (n = 39) groups according to FibroScan and MASLD diagnostic criteria. FibroScan measured LSM and CAP, while enzyme-linked immunosorbent assay kit (ELISA) was used to analyze serum FGF-21 and CK-18 levels. Anthropometric, metabolic, and liver enzyme parameters were assessed. Results: Metabolic dysfunction-associated steatotic liver disease groups had higher LSM than controls. Fibroblast growth factor-21 levels were significantly higher in MASLD groups, especially in obese MASLD, while CK-18 levels showed variability without significant group differences. Obese MASLD adolescents had marked metabolic dysfunction with higher insulin, homeostasis model assessment for insulin resistance, triglycerides, and liver enzymes compared to non-obese MASLD and controls. Conclusion: Fibroblast growth factor-21 has emerged as a potential biomarker for assessing metabolic dysfunction in MASLD, while LSMs from FibroScan provide valuable insights into fibrosis risk. Elevated FGF-21 levels and FibroScan parameters reflect their potential usefulness in non-invasive assessment of MASLD severity, particularly in obese adolescents. However, further longitudinal studies are needed to establish their roles in predicting disease progression and guiding clinical management.