Serotonin levels in adolescents with obesity and non­alcoholic fatty liver disease

The prevalence of obesity has reached epidemic proportions not only among adults, but also in the pediatric population. Expectedly the number of obesity-associated diseases, including non­alcoholic fatty liver disease (NAFLD) etc., increases, too. The pathogenesis of these conditions has common links, some of them are well known, others are being investigated. The latter include hormones of the gastrointestinal tract. They are considered as a part of the body’s humoral regulation. These compounds regulate energy balance of a body, and insulin resistance. It is assumed they can affect obesity and NAFLD pathogenesis. Objective — to determine serotonin levels in adolescents with obesity and NAFLD. Materials and methods. An examination of 108 adolescents aged 12—17 years with obesity (55 boys and 53 girls) was carried out. The control group consisted of 32 healthy adolescents (18 boys and 14 girls). Depending on the hepatobiliary pathology all patients were divided into two groups: 1st group included 29 (26.9 %) adolescents with functional disorders of the biliary tract (FDBT), and 2nd group consisted of 79 patients (73.1 %) with NAFLD and FDBT.All patients underwent a comprehensive clinical and anamnestic examination, clinical and biochemical blood tests, including determination of the levels of γ-glutamyl transpeptidase (GGT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AP), total bilirubin and its fractions, triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), atherogenic coefficient (AC) value. Levels of fasting glucose and immunoreactive insulin (IRI), HOMA-IR index, and blood serotonin level were also determined. An ultrasound examination of the abdominal cavity was performed. Results and discussion. According to the clinical and anamnestic data, there were no differences between the groups of adolescents with obesity, depending on the existing hepatobiliary pathology, except for a higher value of the WC/Height in patients with NAFLD and FDBT (p < 0.01). The results of laboratory investigations demonstrated that in patients with NAFLD and FDBT, compared to patients with FDBT, the following parameters were higher: fasting glucose level (p < 0.05), IRI (p < 0.01), the value of the HOMA-IR index and the frequency of its increase (p < 0.01), levels of ALT and AST activity (p < 0.05), the levels of triglycerides and VLDL-­C (p < 0.05). The level of serotonin was higher in the group of patients with NAFLD and FDBT compared to the control group (p < 0.015). Conclusions. Adolescents with obesity, accompanied by NAFLD and FDBT, had higher rates characterizing abdominal obesity, carbohydrate and lipid metabolism, liver enzyme activity compared to patients with FDBT. Serotonin levels were higher in the group of patients with NAFLD and FDBT compared to the control group.