Comparing Bioelectrical Impedance Analysis, Air Displacement Plethysmography, and Dual-Energy X-Ray Absorptiometry for Body Composition in Pediatric Obesity.

BACKGROUND

Body composition analysis is crucial in clinical practice, yet few methods are suitable for pediatric patients, and data on young children with obesity are limited.

METHODS

This study measured body fat percentage (BFP), fat mass (FM), and fat-free mass (FFM) in 26 pediatric patients with obesity (BMI: 35.6±6.9 kg/m), using two bioelectrical impedance analysis (BIA) devices (TANITA and BIACORPUS), and the results were compared to those of the gold-standard dual-energy X-ray absorptiometry (DXA). Additionally, air displacement plethysmography (BODPOD) was compared with DXA, and all methods were evaluated against each other.

RESULTS

Significant differences were observed between all methods and parameters ( < 0.05). For example, Bland-Altman analysis for BFP identified differences between BIACORPUS and DXA (mean: -3.5%; 95% limits of agreement: -16.7% to 9.8%) and between TANITA and DXA (mean: -3.1%; 95% limits of agreement: -12.2% to 6.1%). These differences can be regarded as clinically relevant, especially when considering the 95% limits of agreement. Further, moderate differences between BODPOD and DXA were identified, which could be clinically relevant (mean: 2.1%; 95% limits of agreement: -4.2% to 8.5%).

CONCLUSIONS

TANITA was the most comparable BIA method to the gold standard, DXA. Therefore, TANITA is recommended for assessing body composition in young patients with obesity to monitor therapy progress in clinical settings. When using BODPOD as an alternative to DXA, caution is warranted since we found relevant differences between both methods.