Body composition measurements by dual-energy x-ray absorptiometry differ between two analysis modes.

Area of Science:

• Human Physiology
• Medical Imaging
• Body Composition Analysis

Background:

• Dual-energy X-ray absorptiometry (DXA) is a widely used method for assessing body composition.
• Different software analysis modes may influence DXA measurement outcomes.
• Understanding these differences is crucial for accurate interpretation of body composition data.

Purpose of the Study:

• To quantify the extent of differences in body composition measurements between standard and extended DXA analysis modes.
• To investigate potential factors contributing to measurement discrepancies, such as bone-edge instability and body mass index (BMI).

Main Methods:

• Whole-body DXA scans were performed on 263 women (aged 20-74 years).
• Each scan was analyzed using both standard and extended analysis modes.
• Measurements included bone mineral density (BMD), bone mineral content (BMC), bone area (BA), fat mass (FM), lean mass (LM), and percentage of fat (%fat).

Main Results:

• The standard mode reported significantly higher BMD, BMC, BA, and %fat, and significantly lower LM compared to the extended mode (p < 0.05).
• A strong correlation was observed between measurement errors in BMC and BA (r = 0.93), suggesting potential bone-edge instability.
• BMI was significantly correlated with BMC measurement error (r = 0.75), indicating obesity may influence accuracy.

Conclusions:

• Significant discrepancies exist between standard and extended DXA analysis modes for various body composition parameters.
• Bone-edge instability and degree of obesity may contribute to measurement errors.
• Caution is advised when comparing multicenter data or intervention effects obtained using different DXA analysis modes.