S2746 Evaluating the Impact of BMI and Diabetes on Non-Invasive Fibrosis Scores in MASLD Patients: A Retrospective Analysis

Introduction: Metabolic dysfunction-associated steatotic liver disease (MASLD) affects over 100 million U.S. adults and is closely linked to obesity and type 2 diabetes. Liver fibrosis, the strongest predictor of liver-related outcomes in MASLD, is routinely assessed using non-invasive markers such as the NAFLD Fibrosis Score (NFS), FIB-4 Index, and aspartate aminotransferase Platelet Ratio Index (APRI). However, the performance of these tools may be confounded by metabolic factors such as body mass index (BMI) and diabetes, which are central to MASLD pathogenesis. We aim to evaluate the association between BMI, diabetes status, and non-invasive fibrosis scores in a retrospective cohort of MASLD patients. Methods: We conducted a single-center retrospective study of patients with a diagnosis code of MASLD from January 1, 2022, until December 31, 2023. Patients were grouped into BMI categories per CDC guidelines (normal: 18.5–24.9; overweight: 25–29.9; obese: ≥30) and by diabetes status. Patients with missing labs were excluded. We compared NFS, FIB-4, and APRI scores across these groups using Kruskal-Wallis tests. We used 2-sided hypothesis tests and a 5% alpha. Results: We reviewed 4644 patients with a diagnosis code of MASLD. 3416 had labs available to calculate the fibrosis scores. Of them, 2233 had imaging-based steatosis while 1183 had no evidence of steatosis. 48% were men, 46.9% were African American, while 27.25% were White. The mean age was 54.7 years, while the mean BMI was 31.5. The number of subjects with advanced fibrosis was 174, 165, and 80 using FIB-4, NFS, and APRI, respectively. With stratification by BMI and DM, using NFS, obese and diabetic subjects respectively had the highest percentage of advanced fibrosis, whereas using FIB-4 and APRI, normal BMI and non-diabetic subjects respectively had the highest percentage of advanced fibrosis even after adjusting for age and platelet count. Conclusion: Our findings suggest that elevated BMI and diabetes are associated with increased likelihood of high-risk NFS scores. However, paradoxically, normal BMI and non-diabetic patients exhibited higher FIB-4 and APRI scores, even after adjustment for age and platelet count, which may suggest potential unexplained confounders. These results highlight the complexity of interpreting fibrosis risk in MASLD and underscore the need to refine non-invasive assessment tools in metabolically diverse populations.