Segmental body composition evaluation by bioelectrical impedance analysis and dual-energy X-ray absorptiometry:...

Area of Science:

• Body composition analysis
• Biomedical engineering
• Human physiology

Background:

• Segmental body composition estimates offer greater health insights than whole-body measures.
• Dual-energy x-ray absorptiometry (DXA) and single-frequency bioelectrical impedance analysis (SFBIA) are common methods for body composition assessment.
• Understanding the agreement between DXA and SFBIA is crucial for accurate health evaluations.

Purpose of the Study:

• To compare total and segmental fat mass (FM) and lean soft tissue (LST) estimates between DXA and SFBIA.
• To quantify the agreement and identify discrepancies in body composition measurements from two different methods.
• To assess the potential clinical utility of SFBIA for body composition analysis.

Main Methods:

• 179 adults (103 F, 76 M) underwent assessments using DXA and SFBIA.
• Total and segmental FM and LST estimates were compared using statistical methods including null hypothesis significance testing (NHST) and equivalence testing.
• Bland-Altman analysis and error metrics were employed to evaluate agreement and bias.

Main Results:

• Lean soft tissue (LST) estimates showed better agreement between DXA and SFBIA than fat mass (FM) estimates.
• Appendicular lean soft tissue (ALST) estimates demonstrated strong equivalence across all analyses.
• Agreement between methods was generally superior in females compared to males, with most FM variables failing to show equivalence.

Conclusions:

• DXA and SFBIA LST estimates exhibit better agreement than FM estimates, with ALST showing particular utility for clinical applications like sarcopenia assessment.
• Overall agreement between SFBIA and DXA may be better in females than males.
• Further research is needed to explore physiological and anthropometric factors influencing discrepancies between DXA and BIA measurements.