MetALD as a Single Clinical Entity Regarding Liver Fibrosis: Comparative Assessment of MASLD-Predominant and ALD-Predominant MetALD Using Shear Wave Elastography and Non-Imaging NILDAs

Aim Metabolic and alcohol-associated liver disease (MetALD) is a newly defined category of steatotic liver disease. It remains unclear whether the severity of fibrosis differs between MASLD-predominant and ALD-predominant MetALD. This study aimed to compare liver stiffness measurements (LSM) using shear wave elastography (SWE) and non-imaging non-invasive liver disease assessments (NILDAs) between these subtypes. Methods In this single-center cross-sectional study, participants with MetALD were stratified into MASLD-predominant (n=176) and ALD-predominant (n=72) groups. Significant fibrosis was defined as a ≥8 kPa. We also compared non-imaging NILDAs (FIB-4 index, NAFLD fibrosis score, Fibrotic NASH index, MAF-5 score, and LiverRisk score) between the two groups. Results No significant differences were observed in LSM (6.35 vs. 6.13 kPa, p=0.1209) or the prevalence of significant fibrosis (36.3% vs. 26.3%, p=0.1308) between the MASLD-predominant and ALD-predominant groups. Similarly, other non-imaging NILDAs, including the Fibrotic NASH index and MAF-5 score, showed no significant differences in the proportion of analyses using clinical cut-offs. In contrast, the proportion of patients with a high FIB-4 index was significantly higher in the ALD-predominant group than in the MASLD-predominant group (18% vs. 30.8%, p=0.0331). Multivariate and decision tree analyses identified the AST levels as the most impacted independent factor of a high FIB-4 index in the ALD-predominant group (OR 1.033, 95%CI 1.011-1.058, p=0.0028). Conclusion Fibrosis severity as assessed by SWE and most non-imaging NILDAs is comparable between MASLD-predominant and ALD-predominant MetALD, supporting their management as a unified clinical entity regarding liver fibrosis. However, the FIB-4 index may overestimate the fibrosis risk in ALD-predominant MetALD due to an alcohol-induced AST elevation.