Endocrine Abstracts

Background: Recent data have been showed that free radicals are involved in either bone resorption and atherosclerosis development in adults. In paediatric population the important risk factor for the early atherosclerosis development is obesity, which can be also associated with the disturb bone turnover.

Objective and hypotheses: The aim of the study was to evaluate the interrelationship between oxidative stress and bone turnover markers in obese children vs lean controls and correlated them with the anthropometrical status and metabolic activity of adipose tissue.

Method: Bone turnover markers (osteocalcin (OC), N-terminal telopeptide of type I collagen (NTx)), oxidative stress markers (TAC – total antioxidative capacity, glutathione peroxidase, oxLDL) and leptin were determined in 50 obese children and 79 healthy controls. Anthropometrical status by BMI calculation and body composition parameters as: fat mass (FAT), fat-free mass (FMM), predicted muscle mass (PMM) and total body water (TBW) were evaluated using bioelectrical impedance analyzer (BIA) in all children.

Results: OC was significantly lower in obese children and correlated significantly (negatively P<0.01) with BMI in the lean group. There was also significant positive correlation between OC and TAC in obese children. NTx correlated significantly with oxy-LDL (positively) in either, obese and lean group (P<0.05 and P<0.01 respectively). In the lean group only, there were significant relations between NTx vs leptin and body composition parameters (r=0.245 vs leptin, r=0.245 vs FAT%, r=−0.252 vs PMM%, and r=−0.245 vs FFM% respectively).

Conclusion: Bone turnover seems to be disturbed in the obese children and pathophysiological factor with can be involved in that mechanism may be an increase oxidative stress level. Osteocalcin and NTx levels seem to be related to the anthropometrical status and adipose tissue activity (leptin level).