Role of serum FGF21 in the diagnosis of metabolic dysfunction–associated fatty liver disease: a case–control study of Egyptian patients

Abstract Background Metabolic dysfunction-associated fatty liver disease (MAFLD) is one of the most common etiologies of hepatic dysfunction worldwide. Fibroblast growth factor 21 (FGF21), a hepatokine involved in lipid metabolism and insulin sensitivity, may serve as a promising biomarker for MAFLD diagnosis and staging. Our study aimed to weigh the value of FGF21 as a sensitive and accurate biomarker of MAFLD. Methods This case–control study involved 80 adults, comprising 40 patients with MAFLD and 40 healthy controls, recruited from Ain Shams University Hospital. All participants had clinical, laboratory, and imaging assessments. Serum FGF21 assay was done using ELISA, and hepatic steatosis and fibrosis were evaluated using ultrasonography, noninvasive scoring methods (FLI, NFS, and FIB-4), and transient elastography. Results Serum FGF21 concentrations were markedly increased in MAFLD patients relative to controls ( p < 0.001). FGF21 exhibited a positive correlation with BMI, waist circumference, insulin resistance, dyslipidemia, liver enzymes, GGT, steatosis, and fibrosis scores. Elevated FGF21 levels were correlated with more advanced stages of steatosis and fibrosis. ROC curve analysis demonstrated excellent diagnostic performance of FGF21 for MAFLD (AUC = 0.964), exhibiting 80% specificity and 97.5% sensitivity at a threshold of 120.32 pg/mL. Conclusion FGF21 is strongly correlated with the severity of MAFLD, making it a potentially useful biological biomarker for diagnosis and disease stratification. Additional comprehensive studies are necessary to confirm its diagnostic and therapeutic efficacy.