Table 1.

Principal studies examining the relationship between NAFLD and psoriasis (ordered by publication year).

Authors, Year (Reference)	Study Characteristics	NAFLD Diagnosis	Main Findings
Gisondi et al. 2009 [19]	Cross-sectional: 130 consecutive Italian patients with chronic plaque psoriasis and 260 healthy controls matched for age, sex and BMI	Ultrasonography	Prevalence of NAFLD was remarkably higher in psoriatic patients than in matched controls (47% vs. 28%; p < 0.001). Patients with psoriasis and NAFLD were more likely to have metabolic syndrome and had higher serum C-reactive protein concentrations and greater severity of psoriasis according to PASI score than those with psoriasis alone. At multivariate linear regression analysis, NAFLD was associated with higher PASI score (standardized β coefficient 0.19, p = 0.03), independent of age, sex, BMI, psoriasis duration and alcohol consumption
Miele et al. 2009 [20]	Retrospective, case-control: 142 Italian patients with psoriasis and 125 non-psoriatic patients with biopsy-proven NAFLD comparable for age and BMI	Ultrasonography and biopsy	Prevalence of NAFLD was 59.2% in the cohort of psoriatic patients. In these patients NAFLD was significantly associated with metabolic syndrome and psoriatic arthritis. Compared with the non-psoriatic NAFLD cohort, psoriatic patients with NAFLD were likely to have more severe NAFLD reflected by either non-invasive NAFLD Fibrosis score or AST/ALT ratio >1
Madanagobalane et al. 2012 [21]	Cross-sectional: 333 Indian psoriatic patients and 330 controls matched for age, sex and BMI	Ultrasonography and liver enzymes	Prevalence of NAFLD was higher in psoriatic patients than in matched controls (17.4% vs. 7.9%; p < 0.005). Psoriatic patients with NAFLD had more severe psoriasis than those without NAFLD. In a subset of participants, psoriatic patients had more severe forms of NAFLD than non-psoriatic patients with NAFLD (as estimated by non-invasive fibrosis markers)
van der Voort et al. 2014 [22]	Cross-sectional: population-based cohort of 2292 Dutch elderly participants (the Rotterdam Study)	Ultrasonography	Prevalence of psoriasis was 5.1% (by a validated algorithm). Prevalence of NAFLD was higher in psoriatic patients than in participants without psoriasis (46.2% vs. 33.3%, p = 0.005). Psoriasis was associated with NAFLD (OR 1.70, 95% CI 1.1–2.6, p = 0.01), independent of age, sex, alcohol consumption, pack-years and smoking status, metabolic syndrome, and serum ALT levels
van der Voort et al. 2015 [23]	Cross-sectional: population-based cohort of 1535 elderly participants (the Rotterdam Study) of whom 74 (4.7%) had psoriasis	Ultrasonography and transient elastography (Fibroscan)	Prevalence of NAFLD was higher in subjects with psoriasis than in those without psoriasis (44.3% vs. 34%, p < 0.05). Moreover, prevalence of advanced liver fibrosis was 8.1% in psoriatic patients compared with 3.6% in the control group (p < 0.05). Multivariate logistic regression analysis revealed that the risk of advanced liver fibrosis remained higher in psoriatic patients after adjustment for age, sex, alcohol consumption, serum ALT levels, presence of metabolic syndrome and hepatic steatosis (OR 2.57, 95% CI 1.0–6.6)
Gisondi et al. 2015 [24]	Cross-sectional: 124 Italian patients with psoriasis and 79 healthy controls	Ultrasonography	Prevalence of NAFLD was higher in psoriatic patients than in controls (44% vs. 26%, p < 0.001). NAFLD fibrosis score was also higher in psoriatic patients (p < 0.001). Multivariate regression analysis revealed that psoriasis was associated with higher NAFLD fibrosis score, independent of age, sex, BMI, hypertension and pre-existing diabetes
Abedini et al. 2015 [25]	Cross-sectional: 123 Iranian patients with psoriasis and 123 healthy controls matched by age, sex and BMI	Ultrasonography	Prevalence of NAFLD was higher in psoriatic patients than in matched controls (65.6% vs. 35%, p < 0.01). Multivariate logistic regression analysis revealed that PASI score, waist circumference, hypertension and serum aminotransferase levels independently predicted the ultrasonographic severity of NAFLD
Roberts et al. 2015 [26]	Cross-sectional: 103 United States adult patients with a diagnosis of psoriasis or psoriatic arthritis	Ultrasonography and biopsy (available in a subgroup of 52 patients)	The overall prevalence of NAFLD was 47%. The prevalence of NASH was 22% in those who underwent liver biopsy. Psoriatic patients with NAFLD had higher mean PASI scores than those without NAFLD
Candia et al. 2015 [27]	Systematic review and meta-analysis: 7 case-control studies included	Ultrasonography and liver enzymes	Psoriatic patients had an increased risk of prevalent NAFLD compared with control subjects (6 studies, n = 267,761 patients, OR 2.15, 95% CI 1.6–2.9, p < 0.05). The risk of prevalent NAFLD was higher in patients with psoriatic arthritis (3 studies, n = 505 patients, OR 2.25, 95% CI 1.4–3.7, p < 0.05) and in those with moderate-to-severe psoriasis compared with patients with mild psoriasis (2 studies, n = 51,930 patients, OR 2.07, 95% CI 1.6–2.7, p < 0.05)

Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; BMI, body mass index; CI, confidence interval; NAFLD, nonalcoholic fatty liver disease; NASH, nonalcoholic steatohepatitis; PASI, psoriasis area and severity index; OR, odds ratio.