Background: The clinical assessment of lean body mass (LBM) is challenging in obese children. A sex-specific predictive equation for LBM derived from anthropometric data was recently validated in children.
Aim: The purpose of this study was to independently validate these predictive equations in the obese paediatric population.
Subjects and methods: Obese subjects aged 4-21 were analysed retrospectively. Predicted LBM (LBMp) was calculated using equations previously developed in children. Measured LBM (LBMm) was derived from dual-energy x-ray absorptiometry. Agreement was expressed as [(LBMm-LBMp)/LBMm] with 95% limits of agreement.
Results: Of 310 enrolled patients, 195 (63%) were females. The mean age was 11.8 ± 3.4 years and mean BMI Z-score was 2.3 ± 0.4. The average difference between LBMm and LBMp was -0.6% (-17.0%, 15.8%). Pearson's correlation revealed a strong linear relationship between LBMm and LBMp (r = 0.97, p < 0.01).
Conclusion: This study validates the use of these clinically-derived sex-specific LBM predictive equations in the obese paediatric population. Future studies should use these equations to improve the ability to accurately classify LBM in obese children.
Keywords: Lean body mass; obesity; paediatric cardiology.