According to recent views, underlying cause and characteristic of type 2 diabetes mellitus (DM2), complicated by non-alcoholic fatty liver disease (NAFLD) is chronic systemic low-gradient inflammation, in which the leading role in liver damage and DM2 decompensation is given to the cytokine production. The purpose of this study was to compare the levels of interleukin 17 (IL-17) expression in patients with DM2 and NAFLD, as well as to assess the relationship between IL-17 and anthropometric (BMI), laboratory characteristics (HOMA-IR, IL-1β, INF-γ, CD-95) in these patients. Methods. We observed 118 patients, including 64 patients with DM2 and NAFLD, 26 patients with DM2 and 28 patients with NAFLD. The control group consisted of 25 apparently healthy individuals. Results. Significant increase in content of IL-17 cytokine in 34 times was established in patients with NAFLD only (P<0.05) and in combination of DM2 and NAFLD (P<0.05), which confirms the presence of progressive inflammatory response in these patients. In addition, IL-17 also contributes to the development of insulin resistance, as it leads to disorder of insulin -mediated glucose transport and suppresses the expression of genes involved in lipid metabolism. Our results also showed that there is a significant positive correlation between IL-17 and BMI (r=0.62, P<0.05), HOMA-IR (r=0.43, P<0.05), and INF- γ (r=0.59, P<0.05).
In the combination of DM2 and NAFLD, the content of INF-γ is increased in 6 times compared to control and in 2 times compared DM2 alone (P<0.05). Such changes lead to a disturbance in insulin signaling in adipocytes, a link that binds mechanisms of T-cell mediated inflammatory process with insulin resistance. IL-17 stimulates macrophages to increased production of IL-1β, which in turn has a cytotoxic effect on beta cells. The excretion of IL-1β in main group was the highest and was 6.85 pg/ml comparing to control of 1.6 pg/ml (P<0.05). The established moderate correlation (r=0.32, P<0.05) between the level of IL-1β and the content of CD-95+ in main group is evidence of inflammatory reactions and apoptotic processes in the liver with further fibrogenesis. Conclusions. The combination of DM2 with NAFLD is accompanied by an elevated IL-17 expression level in all studied groups of patients, its positive correlations with BMI, HOMA-IR, expression of INF-γ, IL-1β and CD-95+. All this, as the mightful inflammatory background, promotes the activation of hepatocyte apoptosis and is an important basis for liver fibrosis progression.
18 May 2019 - 21 May 2019