title: Assessment of EchoMRI-AH versus dual-energy X-ray absorptiometry by iDXA to measure human body composition.
abstract: Comparison of percent fat mass across different body composition analysis devices is important given variation in technology accuracy and precision, as well as the growing need for cross-validation of devices often applied across longitudinal studies. We compared EchoMRI-AH and Lunar iDXA quantification of percent body fat (PBF) in 84 adults (43M, 41F), with the mean age 39.7±15.9 years and body mass index (BMI) 26.2±5.3 kg/m2. PBF correlated strongly between devices (r>0.95, P<0.0001). A prediction equation was derived in half of the subjects, and the other half were used to cross-validate the proposed equation (EchoMRI-AH PBF=[(0.94 × iDXA PBF)+(0.14 × Age)+(3.3 × Female)-8.83). The mean PBF difference (predicted-measured) in the validation group was not different from 0 (diff=0.27%, 95% confidence interval: -0.42-0.96, P=0.430). Bland-Altman plots showed a bias with higher measured PBF on EchoMRI-AH versus iDXA in all 84 subjects (β=0.13, P<0.0001). The proposed prediction equation was valid in our cross-validation sample, and it has the potential to be applied across multicenter studies.
authors.affiliation: Pennington Biomedical Research Center, Baton Rouge, LA, USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Marlatt
authors.affiliation: Pennington Biomedical Research Center, Baton Rouge, LA, USA.
authors.forename: F L
authors.initials: FL
authors.lastname: Greenway
authors.affiliation: Pennington Biomedical Research Center, Baton Rouge, LA, USA.
authors.forename: E
authors.initials: E
authors.lastname: Ravussin
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods / Q000706:statistics & numerical data*; D000328:Adult; D001823:Body Composition; D015992:Body Mass Index; D016001:Confidence Intervals; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D051598:Whole Body Imaging / Q000379:methods / Q000706:statistics & numerical data*