Evaluation of Fibroblast Growth Factor 21 in Occurrence of Non-Alcoholic Fatty Liver Disease among Obese Children and Adolescents

Background: Childhood obesity is one of the most serious global public health challenges of the twenty-first century. Over the past four decades, the number of children and adolescents with obesity has risen more than tenfold. Worldwide, an increasing number of youths are facing greater exposure to obesity throughout their lives, and this increase will contribute to the early development of type 2 diabetes (T2D), fatty liver and cardiovascular complications.Aim: To evaluate the fibroblast growth factor 21 (FGF 21) in occurrence of non-alcoholic fatty liver disease among obese children and adolescents.Subjects and methods: This case control study was conducted from March 2023 till March 2025 on 102 obese patients and 30 healthy control child cross matched with age and sex at Pediatric Department, Faculty of medicine Al-Azhar and Cairo University Hospitals.Results: Both BMI, waist circumference, TGs and FGF 21 separately had a significant value for predicting NAFLD disease among obese cases. FGF 21 levels showed significant positive correlation with the patient's weight, BMI, waist circumference, triglycerides, LDL levels, AST, and ALT. ROC analysis revealed that FGF 21 cut-off value of > 269.9 pg/dl was able to detect cases of fatty liver with an area under curve (AUC) of 0.90, sensitivity of 85.5%, specificity of 78.7% and p- value of < 0.001.Combining BMI, TG, WC, FGF 21, and NAFLD fibrosis scores improves sensitivity and specificity for NAFLD prediction which had the highest values of 94.7% and 88% respectively suggesting a multi-parameter diagnostic approach for predicting NAFLD disease among obese cases with the highest total accuracy of 90.1%.Conclusion: Non-alcoholic fatty liver (NAFLD) is highly prevalent in obese children, with significant relation between obesity and NAFLD. Obese children with NAFLD are at risk for dyslipidemia and liver functions impairment. Obese children with NAFLD showed statistically higher levels of FGF 21, which showed a predictive value for the occurrence of fatty liver. Combining BMI, TG, waist circumference (WC), FGF 21, and NAFLD fibrosis scores improves sensitivity and specificity for NAFLD prediction suggesting a multi-parameter diagnostic approach for predicting NAFLD disease among obese cases.