Plasma concentrations of zonulin are elevated in obese men with fatty liver disease.

Purpose: Zonulin is considered as a biomarker of increased intestinal permeability. The relationship between intestinal permeability and obesity is known, and many studies have investigated the relationship between intestinal permeability and liver disease. Thus, we aimed to investigate the potential association between plasma zonulin concentrations and fatty liver in obese men.

Patients and methods: A total of 140 obese men without inflammatory bowel diseases, autoimmune diseases, and severe liver diseases were included. The subjects were divided into three groups: normal, mild fatty liver, and moderate-to-severe fatty liver, according to abdominal ultrasonography findings. We subdivided the subjects into two subgroups based on the amount of alcohol consumption (appropriate drinking and hazardous drinking), and subgroup analyses were performed.

Results: The mean plasma zonulin concentrations (ng/mL) in the normal, mild fatty liver, and moderate-to-severe fatty liver groups were 0.618, 2.143, and 5.815, respectively ( P <0.001). A multivariate multinomial logistic regression analysis revealed an odds ratio (OR) of 1.77 ( P =0.015) in the moderate-to-severe fatty liver group. The median plasma zonulin concentrations (ng/mL) in the appropriate drinking subgroup of the fatty liver groups were 0.002, 0.500, and 6.550, respectively ( P -trend<0.001), and in the hazardous drinking subgroup were 0.002, 0.590, and 5.800, respectively ( P -trend=0.001). The ORs for moderate-to-severe fatty liver were 1.91 ( P =0.039) in the appropriate drinking group and 1.56 ( P =0.045) in the hazardous drinking group.

Conclusion: Plasma zonulin concentrations were elevated among obese men. A significant association was found between zonulin concentrations and severity of fatty liver.