Liver steatosis in patients with rheumatoid arthritis treated with methotrexate is associated with body mass index

BACKGROUND Methotrexate(MTX)is the usual first-line treatment for rheumatoid arthritis(RA).Long-term use of MTX has been associated with liver steatosis(LS)and liver fibrosis(LF).AIM To determine if LS in patients treated with MTX for RA is associated with MTX cumulative dose(MTX-CD),metabolic syndrome(Mt S),body mass index(BMI),the male sex,or LF.METHODS A single-center,prospective study of patients receiving MTX for RA was performed from February 2019 to February 2020.The inclusion criteria were patients aged 18 years or older diagnosed with RA by a rheumatologist and being treated with MTX(without limitation on the duration of treatment).The exclusion criteria were previous diagnosis of liver disease(hepatitis B or C virus infection,known nonalcoholic fatty liver disease),alcohol consumption greater than 60 g/d in males or 40 g/d in females,human immunodeficiency virus infection on antiretroviral therapy,diabetes mellitus,chronic renal failure,congestive heart failure,or BMI greater than 30 kg/m^(2).Patients receiving leflunomide in the 3 years prior to the study were also excluded.Transient elastography(Fibro Scan,Echosens?,Paris,France)was used for fibrosis determination(LF>7 Kp A)and computer attenuation parameter(CAP)for LS(CAP>248 d B/m).Demographic variables,laboratory data,MTX-CD(>4000 mg),Mt S criteria,BMI(>25),transient elastography,and CAP scores were collected from all patients.RESULTS Fifty-nine patients were included.Forty-three were female(72.88%),and the mean age was 61.52 years(standard deviation:11.73).When we compared MTX-CD≤4000 mg(26 patients;14 with LS and 12 without)with>4000 mg(33 patients;12 with LS and 21 without),no statistical differences were found(P=0.179).We compared CAP scores stratified by Mt S,BMI,sex,and LF.There were no significant differences in CAP scores based on the presence of Mt S[CAP/Mt S:50 no Mt S(84.75%);9 Mt S(15.25%);P=0.138],the male sex(CAP/sex:8 male/18 female LS;8 male/25 female no LS;P=0.576),or LF[CAP/fibrosis:53 no LF(89.83%);6 LF(10.17%);P=0.239].LS determined by CAP was significantly associated with BMI>25(CAP/BMI:22 BMI≤25(37.29%);37 BMI>25(62.71%);P=0.002].CONCLUSION LS in patients with RA treated with MTX was not associated with MTX-CD,LF,the male sex,or Mt S.However,BMI was significantly related to LS in these patients.