In vivo precision of the GE iDXA for the assessment of total body composition and fat distribution in severely obese patients

Objective To evaluate the precision of the iDXA for total body composition and fat distribution measurements in severely obese patients. Design and Methods Sixty-five severely obese participants with a mean age of 46 ± 11years, BMI of 49 ± 6 kg/m2, and a mean body mass of 137.3 ± 20.9 kg took part in this investigation. Two consecutive iDXA scans with repositioning of the total body were conducted for each participant. The coefficient of variation (CV), the root-mean-square (RMS) averages of standard deviations of repeated measurements, the corresponding 95% least significant change, and Intraclass Correlations (ICC) were calculated. Results Precision expressed as % CV, for total body bone mineral content, fat free mass, total body fat, total body lean, and % total body fat were 1.08%, 0.94%, 0.90%, 1.00%, 0.79%, respectively. Precision was 1.44% for gynoid fat distribution and 1.64% for android fat (AF) distribution. The ICCs in all DXA measurements were 0.99 with % AF having the lowest at 0.96. Conclusions The GE Lunar iDXA™ demonstrated excellent precision for total body composition assessments and is the first study to assess reproducibility in severely obese individuals.