Bone mineral density according to age, bone age, and pubertal stages in korean children and adolescents

To determine whether bone age (BA)-based bone mineral density (BMD) reference values are more accurate than chronological age-based BMD values in predicting the BMD of children who have a discrepancy between their chronological age and BA; we calculated BMD reference values for 514 healthy Korean children (262 girls and 252 boys) aged 5-20yr by dual-energy X-ray absorptiometry. We found that children with BA chronological age discrepancy fitted better to the BA BMD reference curve than to the chronological age BMD reference curve. In contrast, most children without BA-chronological age discrepancy fitted well to both BA and chronological age BMD reference curves, because the 2 reference curves are very similar. In the linear regression analysis, BA-based equations for BMD had a higher R(2) value and lower standard error of estimate than chronological age-based equations. These results indicate that BA-based BMD values are more accurate in predicting BMD in children who have a discrepancy between their BA and chronological age.