Dual x-ray absorptiometry, bioelectrical impedance, and near infrared interactance in obese women.

Abstract

Whether the evaluation of body composition in obese people using low-cost, simple bedside, two-compartment techniques reflects the data obtained by indirect methods such as dual x-ray absorptiometry (DEXA) remains controversial. The aim of this study was to compare the data obtained by three methods of assessment of body composition (DEXA; bioelectrical impedance, BIA; and near infrared interactance, NII). Data on body composition obtained in 53 obese women by these three methods were compared, using the Bland and Altman procedure to test the relative validity. Although the correlation coefficients between DEXA and the two other methods were high, there were some major differences (limits of agreement) between data concerning fat and lean mass. The present study indicates that these methods cannot be considered as interchangeable and raises some questions on the use of BIA and NII as a single method of evaluation of body composition in clinical research and practice in obese populations.