A comparison of bone mineral density and body composition between children with developmental coordination disorder and typical development: Dual-energy X-ray absorptiometry

Abstract

Purpose: This study compared the DXA-derived bone mineral density/content (BMD/BMC) and body composition outcomes between DCD and TD children. Methods: One hundred and ninety-six children were recruited and they underwent one whole-body DXA scan (Hologic QDR; Hologic Inc., Bedford, MA). Seventy-seven participants were allocated to the DCD group (mean age ± standard deviation = 8.1 ± 1.1 years; 56 males and 20 females) after screening by a physiotherapist and one hundred and nineteen participants (mean age ± standard deviation = 7.9 ± 1.1 years; 73 males and 47 females) were allocated to the TD group. Participants were ensured to wear loose clothing without metals and did not take any calcium supplements recently. The primary outcome measures included BMD and BMC scores and percentage of body fat. Results: When comparing the differences in body composition and bone strength outcomes between the two groups using multiple Mann-Whitney U tests (with Bonferroni adjustment), results revealed that children with DCD had a significantly higher total age-matched percentage of body fat (7%, p = 0.031) and estimated visceral adipose tissue mass (30 grams, p = 0.002). Aside from body composition, children with DCD had a significantly lower BMC (head excluded) when height was normalized (p = 0.018). However, BMD was not significantly different between the two groups (p = 0.051). Conclusion(s): Children with DCD had relatively higher adipose tissue content and percentage of body fat accompanied with lower BMC than TD children. Implications: This large-scale study provides a representative database of DXA outcomes in children with DCD. Since bone mass and muscle development are closely intertwined during maturation, designing treatments for the DCD population may emphasize on these aspects in the hopes of decreasing the gap between DCD and TD children. Key-Words: 1. Clumsy children 2. Dual-energy X-ray absorptiometry 3. Bone strength Funding Acknowledgements: Study was partially supported by Health and Medical Research Fund (13142081) from the Food and Health Bureau of Hong Kong. Ethics Approval: Human Research Ethics Committee, The University of Hong Kong