Psoriasis Associated with NAFLD, Predominantly in Male Patients

New data from a cross-sectional study found that psoriasis was associated with non-alcoholic fatty liver disease (NAFLD) in adjusted models of the US adult population.

Previous research suggested a high prevalence of NAFLD in patients with psoriasis, with estimates ranging from 44.3% to 65.6%.

Additionally, a 2018 model of NAFLD estimated that an estimated 800,000 liver-related deaths will occur from 2015 to 2030, resulting in a larger health care burden.

Prior to this new data, only 2 studies had evaluated the association between psoriasis and NAFLD in the US.

As such, investigators led by Tao Lu, MD, of The First Affiliated Hospital of Shantou University Medical College in China, sought to expand on the knowledge regarding the association between the 2 condition using data from the National Health and Nutrition Examination Survey (NHANES).

Previously, information regarding psoriasis was only provided for adults 20 to 59 years in the NHANES 2003-2006 cycles and again in the 2009-2014 cycles for adults 16 to 80 years.

For the current study, the team de-identified data from participants 20-59 years old from these cycles before the data were analyzed in June-September 2021.

To restrict their analysis to participants with NAFDL, exclusion criteria included missing data for alcohol consumption or a presence of considerable alcohol consumption, missing data for viral hepatitis or presence of viral hepatitis, or missing data required to calculate US fatty liver index (USFLI) scores.

Meanwhile, psoriasis was defined by responses to the question, “Have you ever been told by a health care provider that you had psoriasis?”, and the presence of NAFLD was defined by a USFLI score of greater than 30, with an area under the receiver operating characteristic curve (AUROC) of 0.80.

Covariates such as age, sex, race and ethnicity, educational level, family income, marital status, diabetes, metabolic syndrome, smoking status, and alcohol drinking status were all included.

A total of 5672 adults with a mean age of 38.9 years were included in the study, 2999 of whom (51.1%) were female. Among these participants, 148 (3%) had psoriasis and 5524 (97%) did not.

A total of 1558 participants (26.8%) were classified as having NAFLD.

A multivariable logistic regression model, after adjusting for the aforementioned covariates and NHANES cycles, found that psoriasis was associated with NAFLD, and subgroup analyses indicated that psoriasis was associated with NAFLD among men (OR, 2.16, 95% CI, 1.10-4.24), and especially in those aged 20-39 years (OR, 2.48, 95% CI, 1.09-5.67), and among those without diabetes (1.70, 95% CI, 1.05-2.76).

Notably, an association between psoriasis and NAFLD use was also found in sensitivity analyses which excluded potential hepatotoxic medication use and non-Hispanic Black participants (OR, 1.76, 95% CI, 1.07-2.87).

The investigators suggested that the association between psoriasis and NAFLD might be bidirectional, which they credited to their similar biological mechanisms. They added that unhealthy lifestyles might be associated with common comorbidities of both psoriasis and NAFLD, such as diabetes and metabolic syndrome.

“The findings of this cross-sectional study suggest that psoriasis is positively associated with NAFLD in the outpatient US adult population,” the team wrote. “Because some antipsoriatic agents are potentially hepatotoxic, this finding may be important for clinicians to consider for psoriasis management.”