RELATIONSHIP BETWEEN LIPID PROFILE AND VITAMIN D IN OBESE ADOLESCENTS WITH HYPOTHALAMIC DYSFUNCTION

Vitamin D deficiency is quite common in pediatric practice, including in overweight/obese patients. Hypothalamic dysfunction in children and adolescents is characterized by excess body weight(BW)/obesity of various degrees, and cardiovascular disorders. Several studies demonstrate an inverse relationship between serum 25-hydroxyvitamin D (25OH)D levels and obesity and insulin resistance. The aim of our study was to examine the relationship between vitamin D status and lipid profile in adolescents with hypothalamic dysfunction and overweight/obesity. 87 children and adolescents with hypothalamic dysfunction (40 boys and 47 girls) were examined. 39 patients (44.8%) were overweight; 23 (26.4%), 16 (18.4%) and 9 (10.4%) people had obesity of the Ist, 2dn, and 3rd degree, respectively. Hypovitaminosis D was established in 88.5% of patients. A comparative analysis of serum 25(OH)D depending on the severity of obesity showed a decrease in its level in patients with excess BW - 69.30 ± 5.14 nmol/l and 1st-degree obesity – 52.60 ± 4.17 nmol/l and significant vitamin D deficiency in persons with the 2nd and 3rd-degree obesity (36.20 ± 3.75 nmol/l, 23.10 ± 3.12 nmol/l, respectively). It has been shown that a decrease in serum 25(OH)D levels is associated with a decrease in HDLC levels, while levels of total cholesterol (TC), triglycerides, LDL-C, and the atherogenicity index reliably increase. The relationship between the levels of vitamin D and the HOMAIR, and leptin and insulin levels is shown. In patients with hypothalamic dysfunction and excess BW/obesity, body mass index is likely to be associated with serum 25(OH)D. The most significant changes in lipid fractions were observed in patients with 3rd-degree obesity, who had the lowest serum 25(OH) D. In patients with hypothalamic dysfunction, an increase in the atherogenicity index and triglyceride levels is observed, corresponding to the rise in obesity degree and a decrease of serum 25(OH)D. It was established that in patients with hypothalamic dysfunction against the background of vitamin D deficiency, there is a reliable increase in the level of TC and HDL-C to the control group in the 3rd degree of obesity and a reliable decrease in HDL-C in the 2nd and 3rd degree of obesity. An increase in leptin and insulin levels occurs already under excess BW, and their levels prolong the increase with increasing obesity degree and vitamin D deficiency. Against the background of hypovitaminosis D, the levels of leptin and insulin in patients with hypothalamic dysfunction exceed the normative indicators by 3.5-7 times with 2nd degree of obesity and 3.5-4 times – with 3rd degree of obesity. In adolescents with hypothalamic dysfunction, a reliable increase (by 2-6 times) of the HOMA-IR is observed in parallel with an increase in the degree of obesity and vitamin D deficiency.