Background: Non-alcoholic fatty liver disease (NAFLD) is accompanied by inflammation and impairment of the lipid metabolism. In addition, NAFLD is one of the major complications of type 2 diabetes associated with oxidative stress. Based on this, we evaluated the tumor necrosis factor alpha (TNF-α), nuclear factor κB (NF-κB), oxidative status rates, and analyzed its correlation with carbohydrate and lipid metabolism in patients with NAFLD and type 2 diabetes.
Methods: A case-control study included 63 participants with NAFLD developing in patients with type 2 diabetes, and 65 healthy volunteers with a normal complete blood count and blood biochemical profile. The following parameters and states were assessed during the study: glycaemia, insulin resistance, lipid levels, liver tests, intensity of free radical induced oxidation, antioxidant enzymes, TNF-α and NF-κB level.
Results: Free radical induced oxidation was significantly elevated (P<0.001), total antioxidant activity was significantly decreased (P<0.001) and associated with insulin resistance (P=0.019) and lipid metabolism shifts (P<0.05) in patients with NAFLD and type 2 diabetes. Such patients had showed impaired functioning of antioxidant system (P<0.001), inhibition of NADPH-generating enzymes activity (P<0.001), increased levels of TNF-α (P<0.001) and NF-κB (P=0.019) correlated with the severity of hyperglycemia (P<0.05), concentration of reduced glutathione (P=0.005) and total cholesterol (P=0.016).
Conclusions: The increase of free radical induced oxidation, TNF-α and NF-κB levels, and depletion of the antioxidant system seems to be the key factors of the development of NAFLD in patients with type 2 diabetes.