Relationships Between Osteocalcin, Glucose Metabolism, and Adiponectin in Obese Children: Is there Crosstalk Between Bone Tissue and Glucose Metabolism?

OBJECTIVE Recently, scientific interest has focused on the association between osteocalcin, which originates from the skeletal system, and glucose metabolism. Although the association between lipid metabolism, adiponectin, and metabolic syndrome is well known, that between obesity, insulin resistance, and osteocalcin have not been clarified yet in children. The aim of this study was to assess the prevalence of insulin resistance in obese children and adolescents, as well as to investigate the effects of adiponectin and osteocalcin on the development of metabolic syndrome and insulin resistance. METHODS A total of 150 obese nondiabetic children and adolescents, aged between 5 and 18 years, were included in the study. Serum adiponectin, osteocalcin and insulin levels were measured, and the association of the components of metabolic syndrome with adiponectin and osteocalcin levels was investigated. Insulin resistance was evaluated by Homeostasis model assessment insulin resistance (HOMA-IR). RESULTS Metabolic syndrome was identified in 28% of the cases, all older than 10 years of age. No significant association was identified between insulin resistance, metabolic syndrome parameters, and osteocalcin levels. Adiponectin levels were significantly low in cases with metabolic syndrome, hyperinsulinemia, and in those with dyslipidemia. No significant association was found between adiponectin and osteocalcin levels. CONCLUSIONS We failed to show the effect of osteocalcin on insulin resistance in obese children and adolescents. This finding may be due to absence of hypergycemic blood glucose levels in our cases.