Open AccessEstimates of Body Fat in Children by Hologic QDR‐2000 and QDR‐4500A Dual‐Energy X‐ray Absorptiometers Compared With Deuterium Dilution
Author(s) -
Robotham Delphine R.,
Schoeller Dale A.,
Mercado Arlene B.,
Mirch Margaret C.,
Theim Kelly R.,
Reynolds James C.,
Yanovski Jack A.
Publication year - 2006
Publication title -
journal of pediatric gastroenterology and nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.206
H-Index - 131
eISSN - 1536-4801
pISSN - 0277-2116
DOI - 10.1097/01.mpg.0000189373.31697.15
Subject(s) - densitometer , nuclear medicine , medicine , dual energy x ray absorptiometry , physics , optics , bone mineral , osteoporosis
We evaluated the accuracy with which the Hologic QDR‐4500A and QDR‐2000 densitometers measure fat mass (FM) in 95 children. FM was derived from total body water measured by deuterium dilution (DD) in all children, by QDR‐4500A in 50, and by QDR‐2000 in 45 children. Compared with DD, both instruments underestimated FM (QDR‐4500A: 3.35 ± 2.5 kg, P < 0.0001; QDR‐2000: 1.05 ± 1.5 kg, P < 0.0001). Both absorptiometers showed magnitude biases relative to DD (QDR‐4500: r = +0.70, P < 0.001; QDR‐2000: r = −0.51, P < 0.001). We conclude that neither densitometer is equivalent to DD for estimation of children's FM. The QDR‐4500A's current calibration seems to provide an even greater underestimate of FM than the QDR‐2000.