Bone Abstracts

Background: Recent data showed that some bone related markers (osteocalcin, 25OHD3) correlate with BMI in the pediatric population. From the other side, obesity in childhood can increase the risk of cardiovascular morbidity and mortality in adulthood. Increased oxidative stress can be one from the causative mechanisms involved in the pathophysiology of almost every complication in obesity. The aim of this study was to determine the relationship between bone turnover markers, nutritional status and oxidative stress markers in obese children comparing to the lean control group.

Material and methods: Bone turnover markers (osteocalcin (OC), N-terminal telopeptide of type I collagen (NTx), sRANKL), oxidative stress markers (TAC – total antioxidative capacity, glutathione peroxidase, oxy-LDL) and leptin were determined in 50 obese children and 79 healthy controls. Nutritional status assessed 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 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). There was no significant correlation between RANKL and every other parameter assessed in both studied groups.

Conclusions: i) 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. ii) Even in lean children nutritional status is inversely and directly related with osteocalcin and NTx respectively.