Within-subject variability in body composition using dual-energy X-ray absorptiometry

Area of Science:

• Human physiology
• Medical imaging technology

Background:

• Dual-energy X-ray absorptiometry (DXA) is a common method for assessing body composition.
• Understanding the reproducibility of DXA measurements is crucial for accurate health assessments.

Purpose of the Study:

• To investigate the reproducibility of DXA for total and segmental body composition measurements.
• To evaluate the variability in bone mineral content (BMC), lean mass, and fat mass.

Main Methods:

• Twenty-two healthy males underwent six consecutive DXA scans within 90 minutes.
• Measurements included total body and segmental (legs, arms, trunk, abdomen) composition.
• Reproducibility was assessed using the coefficient of variation.

Main Results:

• DXA demonstrated excellent reproducibility for bone mineral content (BMC) across all regions.
• Lean tissue reproducibility varied from 1.5% (total body) to 26% (trunk).
• Fat tissue reproducibility ranged from 2.1% (legs) to 50% (total body), with high variability in segments.

Conclusions:

• DXA offers excellent reproducibility for BMC measurements.
• Significant variability exists in DXA measurements of lean and fat tissue, particularly in specific body segments.
• Further research may be needed to improve segmental body composition analysis accuracy.