The purpose of the study was to determine relationship of abdominal fat, adipocytokine, bone mineral density, and bone turnover markers in obese male adolescents. Twenty four male adolescents (obese: 12, normal: 12) volunteered to participate in the study. Anthropometry and skeletal maturity were measured. Body composition and bone mineral density were estimated by DXA (Hologic, QDR-4500, USA). Abdominal fat with total adipose tissue (TAT), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and visceral adipose tissue to subcutaneous adipose tissue ratio (VSR) were estimated by computed tomography (ECLOS, HITACH, Japan). Blood samples were obtained for and analysis of adipocytokines including leptin and adiponectin. Bone turnover markers, osteocalcin (OC), bone-specific alkaline phosphatase (BALP) for bone formation markers and N-terminal telopeptide (NTx), C-terminal telopeptide (CTx) for bone resorption markers were analysed. All data were analyzed utilizing SAS 9.3 (SAS Institute, NC, USA). Independent t-test was used to evaluate the differences between obese adolescents and normal adolescents. Pearson correlation analysis was applied to figure out the relationship between abdominal fat, adipocytokines, bone mineral density, and bone turnover markers. Multiple regression analysis was used to find out the factors of abdominal fat which influence on bone mineral density. A level of significance was set at p<.05. The results of the study indicated that fat tissue (p<.001), percent body fat (p<0.001), TAT (p<.001), VAT (p<.001), and SAT (p<0.001) were significantly higher in obese adolescents than normal adolescents. However bone mineral contents were significantly higher in normal adolescents. Normal adolescents have significantly higher whole body BMD and lumber BMD than obese adolescents. Abdominal fat including VAT and SAT related negatively with whole body BMD and lumbar BMD. Leptin related negatively with BMD whereas adiponectin related positively with BMD. NTx for bone resorption marker related positively with abdominal fat. Visceral adipose tissue was a predictor for whole body BMD and lumbar BMD in explaining 46% and 32% in adolescents. In conclusion, obese male adolescents have lower whole body BMD and lumbar BMD than normal adolescents. Abdominal fat including VAT and SAT related negatively with whole body BMD and Lumbar BMD. And leptin and adiponectin were closely related with BMD. Finally, visceral adipose tissue was a predictor for whole body and lumbar BMD in adolescents.
