Relationship between indices of adiposity obtained by peripheral quantitative computed tomography and dual-energy X-ray absorptiometry in pre-pubertal children

Background/Aim: The study investigated the relationship between indices of adiposity measured by peripheral quantitative computed tomography (pQCT) and dual-energy X-ray absorptiometry (DXA) in pre-pubertal children.

Subjects and methods: DXA-derived per cent body fat (�) was measured in 284 boys and 288 girls, aged 7–10 years. Cross-sections of the forearm (n=427) and lower leg (n=560) were obtained by pQCT to measure total cross-sectional area of the limb (Total CSA), Muscle CSA, Fat CSA, �t CSA (Fat CSA/Total CSA×100) and muscle density.

Results: Peripheral QCT-derived �t CSA in the forearm and lower leg correlated strongly with DXA-derived � (r=0.83–0.89, p<0.01) in both boys and girls. However, forearm and lower leg �t CSA were higher than whole body � by 5% and 10%, respectively. A better prediction of whole-body � was achieved by including �t CSA, muscle density and height into a hierarchical regression model. Using sex-specific regression equations, 87.7% of the boys and 83.7% of the girls had a predicted � within 3% units of the � obtained by DXA.

Conclusion: In pre-pubertal children, pQCT measures of adiposity are strongly associated with whole-body per cent body fat. This reproducible method could be an alternative technique to estimate body composition in this population.