Rheumatoid arthritis is independently associated with metabolic Dysfunction-Associated steatotic liver disease: evidence from the paracelsus 10,000 Population-Based cohort study.

BACKGROUND: Rheumatoid arthritis (RA) is associated with systemic inflammation and increased risk of cardiovascular and metabolic comorbidities. The relationship between RA and metabolic dysfunction-associated steatotic liver disease (MASLD) has not been established in population-based studies. METHODS: We conducted a cross-sectional analysis of 6638 participants from the population-based Paracelsus 10,000 cohort in Austria, including 187 individuals with physician-diagnosed RA meeting ACR/EULAR classification criteria. MASLD was defined using the Fatty Liver Index (≥ 60) combined with cardiometabolic risk factors according to 2024 EASL guidelines. We used Poisson regression models with sequential adjustment for demographic factors, metabolic syndrome, lifestyle factors, NSAID use, and cardiovascular risk (SCORE2). Liver fibrosis risk was assessed using the Fibrosis-4 Index (FIB-4). RESULTS: MASLD prevalence was higher in RA patients than controls (41.2% vs. 28.5%, P < 0.001). In sequential regression models, the association between RA and MASLD persisted after adjustment for demographics (IRR, 1.55; 95% CI 1.33-1.82), metabolic and lifestyle factors (IRR, 1.20; 95% CI 1.03-1.40), and cardiovascular risk factors (IRR, 1.35; 95% CI 1.14-1.60; P < 0.001). In addition, RA patients showed elevated liver fibrosis markers (median FIB-4: 1.21 vs. 1.08; P < 0.001). CONCLUSIONS: In this population-based cohort, RA was independently associated with a 35% increased risk of MASLD and elevated liver fibrosis markers. These findings suggest that systematic liver assessment should be considered in the routine care of RA patients.