Abstract:

In parallel with the obesity epidemic in the world, the prevalence of non-alcoholic fatty liver disease among children and adolescents is growing. Current data suggest that insulin resistance is one of the main factors in the pathogenesis of non-alcoholic fatty liver disease, and the content of fragments of caspase-cleaved cytokeratin-18 in the blood serum may be one of the informative indicators of non-alcoholic fatty liver disease progression. The aim. To determine mechanisms of formation and progression of non-alcoholic fatty liver disease in obese children and adolescents by evaluating the level of cytokeratin-18. Materials and methods. The study involved 46 adolescents with obesity and non-alcoholic fatty liver disease aged 12–17 years: 19 boys (41.3 %) and 27 girls (58.7 %). Clinical (weight, height, waist and hip circumference), laboratory (glucose, immunoreactive insulin, lipid metabolism, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, cytokeratin-18) parameters were studied and instrumental examination (abdominal ultrasound) was performed. To assess insulin resistance the triglyceride-glucose index was calculated. Results. Depending on the presence of insulin resistance patients were divided into two groups: 21 (45.7 %) of adolescents with insulin resistance and 25 (54.3 %) of adolescents without insulin resistance. Blood tests in patients with insulin resistance revealed significantly higher levels of total cholesterol, triglycerides, very low-density lipoprotein cholesterol, fasting immunoreactive insulin, cytokeratin-18 and gamma-glutamyl transpeptidase. All adolescents were divided into 2 groups depending on the level of cytokeratin-18: patients with cytokeratin-18 >233 mIU/ml and <233 mIU/ml (15 (32.6 %) and 31 (67.4 %) respectively). It was found that there were significantly more patients with insulin resistance in the group with the level of cytokeratin-18 >233 mIU/ml. Conclusion. In obese adolescents with non-alcoholic fatty liver disease insulin resistance is associated with more pronounced disorders of lipid and carbohydrate metabolism and higher levels of markers that characterize the state of the liver such as cytokeratin-18 and gamma-glutamyl transpeptidase. Adolescents with obesity and non-alcoholic fatty liver disease with a threshold level of cytokeratin-18, which indicates the transformation of steatosis into steatohepatitis, two times more often have present insulin resistance.

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