Cytokines, insulin resistance and arterial wall stiffness in assessing the course of non-alcoholic fatty liver disease

Abstract

The progression of non-alcoholic fatty liver disease is associated with an increased prevalence of cardiovascular disease. Aim: to assess the level of cytokines, insulin resistance, arterial wall stiffness during the progression of hepatic steatosis in patients with non-alcoholic fatty liver disease. Material and methods. 87 patients with non-alcoholic fatty liver disease were examined. Group I consisted of 14 patients without steatosis, group II – 32 patients with steatosis grade 1; III – 30 patients with steatosis grade 2, IV group – 11 patients with steatosis grade 3. The control group consisted of 30 apparently healthy individuals. Steatometry with a quantitative assessment of the grade of hepatic steatosis was performed using a Soneus P7 ultrasound machine. The content of cytokines (interleukin-6, interleukin-10, TNF-α) was determined using an enzyme-linked immunosorbent assay using a Stat Fax 303 Plus analyzer. The level of insulin resistance was determined using the HOMA-IR index. Results. The content of interleukin-6 in the blood serum of patients of group IV was significantly increased relative to the level in the control group (by 1.8 times, P < 0.05), patients of group I (by 3.2 times, P < 0.05), II group (by 3.0 times, P < 0.05) and group III (2.3 times, P < 0.05). The level of TNF-α increased with the progression of structural changes in the liver and at grade 4 of steatosis its content was increased by 6.4 times (P < 0.05) relative to the level in the control group, by 8.0 times (P < 0.05) relative to group I patients, by 3.4 times (P < 0.05) – group II patients and by 1.8 times (P < 0.05) – group III patients. An increase in the HOMA-IR index by 3.2 times (P < 0.05) was found in patients with moderate steatosis and 3.9 times (P < 0.05) in patients with severe steatosis compared to controls. A correlation was established between the intima-media thickness of the left common carotid artery and the level of TNF-α (r = 0.438; P = 0.006) and the HOMA-IR index (r = 0.557; P = 0.0008). Conclusions. In patients with non-alcoholic fatty liver disease with progression of the grade of hepatic steatosis, a significant increase in proinflammatory cytokines, insulin resistance and intima-media thickness of the left common carotid artery was found.