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

<i><b>Background/Aim:</b> </i>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.<br /><br /><i><b>Subjects and methods:</b> </i>DXA-derived per cent body fat (%BF) was measured in 284 boys and 288 girls, aged 7–10 years. Cross-sections of the forearm (<i>n</i>=427) and lower leg (<i>n</i>=560) were obtained by pQCT to measure total cross-sectional area of the limb (Total CSA), Muscle CSA, Fat CSA, %Fat CSA (Fat CSA/Total CSA×100) and muscle density.<br /><br /><i><b>Results:</b></i><b> </b>Peripheral QCT-derived %Fat CSA in the forearm and lower leg correlated strongly with DXA-derived %BF (<i>r</i>=0.83–0.89, <i>p</i><0.01) in both boys and girls. However, forearm and lower leg %Fat CSA were higher than whole body %BF by 5% and 10%, respectively. A better prediction of whole-body %BF was achieved by including %Fat 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 %BF within 3% units of the %BF obtained by DXA.<br /><i><br /><b>Conclusion:</b></i> 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.<br />