Liver Abnormalities in Patients with Psoriatic Arthritis.

OBJECTIVE: We aimed to determine the prevalence and incidence, and to identify the factors associated with liver abnormalities in patients with psoriatic arthritis (PsA).

METHODS: From a longitudinal cohort study, we identified PsA patients with either elevated serum transaminase or alkaline phosphatase levels or liver disease after the first visit to the PsA clinic (cases). Controls were subjects from the same cohort who never had such abnormalities or liver disease. Cases and controls were matched 1:1 by sex, age at the first clinic visit, and followup duration; variables at the onset of the first appearance of liver test abnormality associated with liver abnormalities were identified using univariate logistic and multivariate logistic regression analyses.

RESULTS: Among 1061 patients followed in the PsA clinic, 343 had liver abnormalities. Two hundred fifty-six patients who developed liver abnormalities after the first visit were identified as cases, and 718 patients were identified as controls. The prevalence of liver abnormalities was 32% and the incidence was 39/1000 patient-years where there were 256 cases over 6533 total person-years in the PsA cohort. Liver abnormalities were detected after a mean (SD) followup duration of 8.3 ± 7.8 years. The common causes of liver abnormalities were drug-induced hepatitis and fatty liver. Independent factors associated with liver abnormalities were higher body mass index (BMI), daily alcohol intake, higher damaged joint count, elevated C-reactive protein, and use of methotrexate, leflunomide, or tumor necrosis factor inhibitors.

CONCLUSION: Liver abnormalities are common among patients with PsA and are associated with higher BMI, more severe disease, and certain therapies.