Obesity increases precision errors in total body dual-energy x-ray absorptiometry measurements
Blake, Glen M.
Journal of Clinical Densitometry
© 2015. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0
Reason for embargo
Total body (TB) dual-energy X-ray absorptiometry (DXA) is increasingly being used to measure body composition in research and clinical settings. This study investigated the effect of body mass index (BMI) and body fat on precision errors for total and regional TB DXA measurements of bone mineral density, fat tissue, and lean tissue using the GE Lunar Prodigy (GE Healthcare, Bedford, UK). One hundred forty-four women with BMI's ranging from 18.5 to 45.9kg/m<sup>2</sup> were recruited. Participants had duplicate DXA scans of the TB with repositioning between examinations. Participants were divided into 3 groups based on their BMI, and the root mean square standard deviation and the percentage coefficient of variation were calculated for each group. The root mean square standard deviation (percentage coefficient of variation) for the normal (<25kg/m<sup>2</sup>; n=76), overweight (25-30kg/m<sup>2</sup>; n=36), and obese (>30kg/m<sup>2</sup>; n=32) BMI groups, respectively, were total BMD (g/cm<sup>2</sup>): 0.009 (0.77%), 0.009 (0.69%), 0.011 (0.91%); total fat (g): 545 (2.98%), 486 (1.72%), 677 (1.55%); total lean (g): 551 (1.42%), 540 (1.34%), and 781 (1.68%). These results suggest that serial measurements in obese subjects should be treated with caution because the least significant change may be larger than anticipated.
This is the author’s version of a work that was accepted for publication in the Journal of Clinical Densitometry. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published at doi: 10.1016/j.jocd.2014.06.001.
Journal of Clinical Densitometry, 2015, Vol. 18 (2), pp. 209 - 216