Is There Difference of BMD between Non-Obese and Obese Children? - A Cross-Sectional Study in 194 Thai Children

Abstract

Objective: To find the correlation between the presence of childhood obesity and bone mineral density (BMD). Materials and Methods: A cross-sectional study was conducted among children aged between 5 and 12 years old. After excluding children who had history of endocrinopathy, epilepsy, or cerebral palsy, all participants were divided into “obese group” (body mass index [BMI] at or above the 95 percentile of those with the same age and gender) and “control group” (BMI below the 95 percentile). Skeletal age, BMD, serum bone markers (osteocalcin and beta-crosslaps), and physical exercise were collected. Multivariate regression analysis was used for statistical analysis. Results: Ninety-six obese children and 98 controls were included in the present study. The average BMI was 28.5 kg/m² in obese group, and 16.6±1.9 kg/m² in controls (p<0.001). BMDs of the spine and hip area were significantly higher in obese group compared to controls (p=0.002 and <0.001, respectively). However, there was no significant difference of skeletal age or serum bone markers level between both groups (p>0.05 all). Exercise was shown to significantly correlated with hip and distal radius BMD (p<0.001 and 0.003, respectively). Conclusion: Obese children had significantly higher spine and hip BMD than non-obese children. Nevertheless, there were no differences between groups regarding skeletal age and bone markers. BMI and exercise activity might play an important role in higher BMD in children. Keywords: Bone mineral density, Children obesity