VITAMIN D DEFICIENCY AND FACTORS OF METABOLIC SYNDROME IN OVERWEIGHT AND OBESE ADOLESCENTS

Abstract

Introduction. Vitamin D deficiency is widespread worldwide and rises with increasing passive lifestyles and bad habits. Vitamin D metabolites are associated with cell differentiation and apoptosis and influence carbohydrate and lipid metabolism. Both changes in lipid and carbohydrate metabolism, as well as a recent increase in sedentary lifestyle, contribute to metabolic syndrome development. The aim of the study was to investigate the relationship between vitamin D status and metabolic syndrome criteria in overweight and obese adolescents. Methods. The study included 196 adolescents, aged 12-17 years. 136 children with overweight and obesity and 60 children with normal body weight, which formed the control group. Auxological and biochemical parameters were studied in all children. Vitamin D status was evaluated and determined according to the International Society of Endocrinology recommendations. The criteria for metabolic syndrome were determined according to the consensus of the International Diabetes Federation. Results. Among enrolled children predominantly was found vitamin D insufficiency and deficiency. Vitamin D deficiency increased with increasing of body weight in adolescents, and it reached up to 74,3% in overweight and obese children. In addition to the relationship with body mass index, was found an association between increased vitamin D deficiency and increased abdominal fat, which is also a predictor of metabolic syndrome. In children with vitamin D deficiency was defined increase by 52,4% atherogenic index, as well as decreased alpha lipoprotein levels by 11,4% at vitamin D levels < 20 ng/ml, and by 25,70% at < 10 ng/ml, respectively. It was found that the level of 25(OH)D in the blood serum was inversely associated with insulin (r=-0,501; p=0,001) levels and HOMA-IR (r=-0,511; p=0,001). Adolescents with vitamin D deficiency have shown more often hyperinsulinemia and insulin resistance. In 49,6% of obese and overweight children, there was a combination of abdominal obesity with two or more criteria of metabolic syndrome. Conclusions. In this study, we found low levels of vitamin D in adolescents and its association with body mass index and metabolic syndrome criteria. Vitamin D deficiency in adolescence can contribute to the development of diseases associated with obesity, insulin resistance, type 2 diabetes mellitus, hypertension, and cardiovascular disease