Study data published in Clinical Rheumatology suggest that insulin resistance, rather than arthritis, may predict nonalcoholic fatty liver disease (NAFLD) in patients with psoriasis. In fact, a higher prevalence of NAFLD was observed among patients with psoriasis (PsO) without arthritis compared with patients with psoriatic arthritis (PsA).
Adult patients with PsO and PsA were consecutively enrolled over a 9-month period from the rheumatology and dermatology units of the University of Padova in Italy. Exclusion criteria were liver diseases other than NAFLD, alcohol consumption ≥20 g/day, daily use of nonsteroidal anti-inflammatory drugs, and current or prior methotrexate use. After enrollment, patients attended a single study visit where they provided demographic and clinical data. Serologic samples were taken to assess biomarker levels. Insulin resistance was evaluated through the homeostatic model assessment (HOMA) index. Patients also underwent liver ultrasound to identify the presence of NAFLD. Transient elastography was performed to evaluate the presence and grading of liver fibrosis, with stiffness ≥7 kPa denoting fibrosis. Multivariable regression analyses were performed to identify the contribution of arthritis to NAFLD and liver stiffness in the whole cohort.
A total of 76 patients attending the University of Padova were enrolled, among whom 43 had PsA and 33 had PsO. The prevalence rates of metabolic syndrome (35% vs 33%; P =.88) and liver fibrosis (31% vs 28%; P =.77) were similar between the PsA and PsO cohorts. However, NAFLD was more frequent in patients with PsO compared with patients with PsA (65% vs 35%; P =.044). In the final multivariable model, insulin resistance and gender, rather than arthritis, emerged as an independent predictor of NAFLD and liver fibrosis grading. HOMA was independently associated with both NAFLD (odds ratio, 1.34; 95% CI, 1.06-1.69) and liver fibrosis grading (beta, 0.88; 95% CI, 0.54-1.21). Female sex was associated with liver fibrosis grading only (beta, 1.81; 95% CI, 0.05-3.57). As such, insulin resistance, rather than arthritis, appeared to be a primary determinant of NAFLD and liver fibrosis in this cohort.
The role of insulin resistance in NAFLD and liver fibrosis development merits further research. In addition, the calculated prevalence rates of metabolic syndrome, liver fibrosis, and NAFLD across patients with PsA and PsO may assist clinicians in calculating patient risk profiles.
Disclosures: The study was conducted in accordance with the Declaration of Helsinki.
Ortolan A, Lorenzin M, Tadiotto G, et al. Metabolic syndrome, non-alcoholic fatty liver disease and liver stiffness in psoriatic arthritis and psoriasis patients [published online June 28, 2019]. Clin Rheumatol. doi:10.1007/s10067-019-04646-7