Assessing the diagnostic value of zonulin as a biomarker for intestinal permeability in patients with metabolic-associated fatty liver disease in combination with type 2 diabetes mellitus

The aim of the study was to assess the diagnostic value of serum zonulin concentrations in patients with metabolic-associated fatty liver disease (МAFLD) in combination with type 2 diabetes mellitus (T2DM). Materials and methods. The study involved 93 patients with MAFLD in combination with T2DM, who were examined and allocated to two groups. Group 1 consisted of 48 patients with non-alcoholic steatohepatitis (NASH) in combination with T2DM without small intestinal bacterial overgrowth (SIBO) syndrome. Group 2 comprised 45 patients with NASH in combination with T2DM and SIBO. The control group consisted of 25 apparently healthy persons. The ELISA method was used for quantitative determination of serum zonulin. Results. When comparing parameters of liver functional activity and ultrasonographic findings of liver steatosis and fibrosis, a significant increase in the activity of ALT and AST was revealed in Group 1 – 67.22 ± 2.25 U/l and 52.97 ± 1.04 U/l (p < 0.001) and in Group 2 – 69.20 ± 1.52 U/l and 54.82 ± 1.10 U/l (p < 0.001) compared to those in the control group – 18.00 ± 1.01 U/l and 18.96 ± 0.82 U/l (p < 0.001) respectively, as well as an increase in the ultrasound attenuation coefficient (UAC) in patients of Groups 1 and 2 amounting to 2.94 ± 0.03 dB/cm and 2.92 ± 0.04 dB/cm, respectively, and also the liver stiffness (LS) in Group 1 – 8.06 ± 0.07 kPa and in Group 2 – 8.00 ± 0.06 kPa compared to those in the control group (p < 0.001). When measuring the level of serum zonulin, a significant increase was revealed in patients of Group 1 – 61.69 ± 1.04 ng/ml and Group 2 – 89.39 ± 1.30 ng/ml compared to that in the control group – 16.76 ± 1.47 ng/ml (p < 0.001). Analyzing correlation coefficients in patients of Groups 1 and 2, a positive linear moderate association was found between the serum zonulin concentration and the activity of ALT, AST and UAC and LS. Conclusions. The study resultsobtained have demonstrated the great diagnostic value of serum zonulin as a biomarker of intestinal permeability in NASH patients in combination with T2DM, and with or without SIBO.