Body composition results by DXA differ with manufacturer, instrument generation and software version

摘要

Dual-energy X-ray absorptiometry (DXA) which has recently been applied to measurements of body composition, in both clinical and research settings, has improved the accuracy and precision of body composition measurements (Mazess et al., 1990; Svendsen el al., 1993). However, changing from one manufacturer to another or from a first-generation to a second-generation DXA system, the results might not be directly comparable. The major manufacturers of DXA use different hardware and software for their calibration, data collection and analyses Previous studies in healthy normal weight subjects have shown that body composition results from the different manufacturers differ (Tothill et al., 1994: Pritchard et al., 1992). Furthermore, the accuracy of body composition measurements by DXA seems to depend on the composition and mass of soft tissue (Aloia et al.. 1995: Jebb et al., 1995; Tothill and Avenell, 1994: Laskey et al., 1992; Mazes et al., 1991), and the differences in body composition results between different manufacturers may differ with fatness, and may thus be different in normal weight, obese and lean subjects. Thus, the aim of the present study was to compare measurements of body composition by DXA with instruments from two different manufacturers in a population of both lean and obese subjects.