Bone mineral density and hormonal status in adolescent athletic girls

Abstract

The aim of this study was to determine the relationships of bone mineral density (BMD) and content (BMC) with selected fasting hormones in adolescents with different exercise training patterns. The participants were female athletes of weight-loaded (n=23) and weight-supported (n=24) sports, and 33 non-athletic girls aged 13–15 years. BMD (g/cm2) and BMC (g) at the femoral neck (FN) and lumbar spine (LS) were measured. Venous blood samples were drawn to determine the concentration of insulin-like growth factor-1 (IGF-1), IGF binding protein-3 (IGFBP-3), estradiol, visfatin, adiponectin, leptin, insulin, and glucose. After adjusting for age, height, and body mass, the relationships of BMD variables with IGF-1, IGF-1/IGFBP-3 molar ratio, estradiol, and leptin levels remained significant only in the weight-loaded sport group (r=0.41–0.60; p<0.05). Adiponectin was inversely correlated to FN and LS BMD and BMC (r=–0.47–0.62; p<0.05) in weight-supported sport group only, but after adjustments for age, height, and body mass, these associations disappeared. In this study, concentrations of visfatin, a fairly new adipocytokine, were not related to bone parameters in adolescent girls with different training patterns.