Features of using non-invasive tests for assessment of liver fibrosis in obese adolescents

Background. The prevalence of obesity among children has become a global epidemic today. The importance of this problem is caused by the development of insulin resistance and metabolic syndrome, the hepatic manifestation of which is considered the development of non-alcoholic fatty liver disease (NAFLD), which can lead to the formation of fibrotic changes in the organ already in childhood. The use of non-invasive assessment of liver fibrosis in obese children with NAFLD allows avoid the liver biopsy in some patients, therefore, it is an urgent issue of pediatrics. The purpose of the study was to examine the possibility of using non-invasive tests to assess liver fibrosis in obese adolescents, depending on the presence of insulin resistance. Materials and methods. The study involved 84 adolescents with obesity aged 12–17 years old. A clinical, laboratory and instrumental examination was conducted. For the assessment of liver fibrosis, the following indices were calculated: AST to Platelet Ratio Index (APRI), pediatric NAFLD fibrosis index (PNFI) и Fibrosis-4 (FIB-4). Results. The basic complains among obese adolescents were: increased appetite — 78.6 %, dyspepsia — 54.8 %, abdominal pain — 52.3 %. Depending on the presence of insulin resistance (IR), the patients were divided into two groups: 66.7 % of adolescents with IR and 33.3 % of adolescents without IR. Biochemical analysis of blood in patients with IR revealed significantly higher levels of triglycerides, very low density lipoprotein cholesterol, atherogenic coefficient, HOMA-IR. According to ultrasound examination results, 82.1 % of patients showed signs of NAFLD. When assessing liver fibrosis by calculating PNFI, 35.7 % of patients demonstrated fibrosis signs, and its mean values were significantly higher in patients with IR. There were no patients with signs of significant liver fibrosis on the basis of calculation of FIB-4 and APRI indices, regardless of IR presence. Conclusions. 82.1 % of obese adolescents had signs of NAFLD and 66.7 % were diagnosed with IR. The use of indices for assessing liver fibrosis revealed PNFI to be the most informative one, which showed signs of fibrosis in a one third of obese adolescents