Hepatic fibrosis in patients diagnosed with rheumatoid arthritis and psoriatic arthritis receiving methotrexate: A cross‐sectional analysis using transient elastography

Abstract Background Among patients diagnosed with rheumatoid arthritis (RA) and psoriatic arthritis (PsA), several factors have been associated with hepatic fibrosis, including exposure to methotrexate (MTX) and metabolic syndrome. In this study, we compared the prevalence of hepatic fibrosis in RA and PsA patients who had been taking MTX, and explored factors associated with hepatic fibrosis in these patients. Methods Patients with RA or PsA who were treated with MTX and managed at the rheumatology clinic, Thammasat University Hospital, between November 2022 and December 2023 were included. Hepatic fibrosis was detected using transient elastography (TE). The prevalence of hepatic fibrosis was compared between the RA and PsA patients. Multivariable linear regression analysis was performed to determine the factors associated with hepatic fibrosis, with emphasis on metabolic syndrome and cumulative methotrexate dose. Results Among the 295 recruited patients, 185 (62.7%) were diagnosed with RA and 110 (37.2%) with PsA. Hepatic fibrosis detected by TE was found in 28.6% of RA patients and 45.5% of PsA patients, respectively. Higher prevalence of metabolic syndrome was observed in the PsA subgroup than that in RA subgroup. The linear regression analysis identified the association between hepatic fibrosis and metabolic syndrome (regression coefficient: 4.127; 95% confidence interval: 3.389 to 4.864; p < 0.001). Notably, cumulative MTX dose and MTX dose per body weight were not associated with hepatic fibrosis in the current analysis. Conclusions Patients with PsA have a higher prevalence of metabolic syndrome and hepatic fibrosis than those with RA. Metabolic syndrome is associated with hepatic fibrosis, even after adjusting for MTX exposure and types of inflammatory arthritis.