Prevalence, characteristics and severity of non-alcoholic fatty liver disease in patients with chronic plaque psoriasis☆

Background / Aims

The association between NAFLD and psoriasis has never been explored in prospective epidemiological studies. The aim of this 2-phase study was to study the clinical features of NAFLD in patients with psoriasis.

Methods

Phase 1: Investigation of prevalence and characteristics of NAFLD in an unselected cohort of 142 adult Italian outpatients with psoriasis vulgaris. Phase 2: Comparison of the psoriasis cohort subgroup with NAFLD and an age- and body mass index-matched retrospective cohort of 125 non-psoriasis patients with biopsy proven NAFLD.

Results

Based on histories, laboratory tests, and ultrasound studies, 84 (59.2%) received clinical diagnosis of NAFLD; 30 had factors potentially associated with liver disease other than NAFLD (e.g., viral hepatitis, significant ethanol, methotrexate use); and 28 (19.7%) had normal livers. Comparison of the normal-liver and NAFLD subgroups revealed that NAFLD in psoriasis patients (Ps-NAFLD) was significantly correlated with metabolic syndrome (p<0.05); obesity (p=0.043); hypercholesterolemia (p=0.029); hypertriglyceridemia (p<0.001); AST/ALT ratio >1 (p=0.019), and psoriatic arthritis (PsA) (p=0.036). The association with PsA remained significant after logistic regression analysis (OR=3.94 [CI, 1.07–14.46]). Compared with the retrospective non-psoriatic NAFLD cohort (controls), Ps-NAFLD patients (cases) were likely to have severe NAFLD reflected by non-invasive NAFLD Fibrosis Scores and AST/ALT >1.

Conclusions

NAFLD is highly prevalent among psoriasis patients, where it is closely associated with obesity (overall and abdominal), metabolic syndrome, and PsA, and more likely to cause severe liver fibrosis (compared with nonPs-NAFLD). Routine work-up for NAFLD may be warranted in patients with psoriasis, especially when potentially hepatotoxic drug therapy is being considered.

Abbreviations: PsA, Psoriatic arthritis, NAFLD, non-alcoholic fatty liver disease, NASH, non-alcoholic steatohepatitis, Ps-NAFLD, NAFLD associated with psoriasis, PASI, psoriasis area and severity index, BMI, body mass index, ALT, alanine aminotransferase, AST, aspartate aminotransferase, γGT, gamma glutamyl transpeptidase, HDL, high density lipoprotein, HOMA, homeostatic model assessment, NFS, NAFLD Fibrosis Score, ATPIII, Adult Treatment Panel III, SD, standard deviation, CI, confidence intervals, OR, odds ratio

Keywords: NAFLD, Steatosis, Psoriatic arthritis, Methotrexate, Fibrosis, Liver function test