Clinical utility of the MAF-5 score for assessing MAFLD/MASLD in a Japanese population with obesity.

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) coexists with type 2 diabetes and is rising in Japan. Liver fibrosis progression in MASLD causes adverse outcomes, highlighting the need for early risk stratification. The utility of the Metabolic Dysfunction-Associated Fibrosis 5 (MAF-5) score has not been assessed in Japanese populations, especially among individuals with type 2 diabetes. Herein, the clinical relevance of the MAF-5 score was assessed in Japanese patients with MASLD. Methods: This prespecified secondary analysis used data from a study titled "A Study to Estimate the Severity of MAFLD Using Continuous Glucose Monitoring." Sixty-six patients diagnosed with metabolic dysfunction-associated fatty liver disease (MAFLD) underwent vibration-controlled transient elastography. All participants were subsequently confirmed to meet the revised diagnostic criteria for MASLD. The MAF-5 score and FIB-4 index were calculated for each participant. Correlations between these scores and liver stiffness measurement (LSM) were assessed using Spearman's rank correlation coefficient. Significant fibrosis was defined as LSM ≥ 8.0 kPa. The predictive performance of each score was evaluated using the area under the receiver operating characteristic curve (AUROC). Results: The final analysis included 57 participants (28 with type 2 diabetes). The MAF-5 score significantly correlated with LSM, whereas the FIB-4 index did not. These associations were consistent regardless of diabetes status. The AUROC for the MAF-5 score was higher than that for the FIB-4 index. Conclusion: The MAF-5 score may serve as a useful noninvasive marker for predicting liver fibrosis in Japanese patients with MASLD, regardless of diabetes status.