Fat Mass Does Not Increase the Precision Error of Trabecular Bone Score Measurements

Area of Science:

• Osteoporosis research
• Bone microarchitecture analysis
• Medical imaging diagnostics

Background:

• Trabecular bone score (TBS) offers insights into bone microarchitecture.
• Previous studies indicated soft tissue thickness does not affect TBS reproducibility.
• The impact of increasing body mass index (BMI) and waist circumference on TBS precision in patients remained unclear.

Purpose of the Study:

• To investigate the effect of increasing BMI and waist circumference on TBS precision error in patients.
• To compare the precision error of TBS with bone mineral density (BMD) under varying body compositions.

Main Methods:

• Postmenopausal Caucasian women were categorized by BMI (normal, overweight, obese) and waist circumference (≤88 cm, >88 cm).
• In vivo precision error was assessed on 30 subjects scanned twice with repositioning using a Hologic QDR-Discovery W densitometer.
• Coefficient of variation, percent least significant change, and reproducibility were calculated per International Society for Clinical Densitometry guidelines.

Main Results:

• No significant differences in BMD or TBS precision errors were observed across BMI or waist circumference groups.
• TBS reproducibility ranged from 95.8% to 96.6%, while BMD reproducibility ranged from 95.9% to 97.5%.
• TBS values significantly decreased with increasing BMI and waist circumference.

Conclusions:

• TBS precision error is unaffected by variations in BMI and waist circumference.
• TBS reproducibility is slightly lower than BMD, with this difference diminishing in obese patients.
• Higher fat mass was negatively associated with mean TBS values.