ASSESSMENT OF BODY-COMPOSITION WITH USE OF DUAL-ENERGY X-RAY ABSORPTIOMETRY - EVALUATION AND COMPARISON WITH OTHER METHODS

Dual-energy x-ray absorptiometry (DEXA) is a relatively new method of assessing body composition in humans. In the current study, DEXA was a nalyzed for accuracy and precision by using both anthropomorphic phant oms and a combination of body composition techniques in humans. Satisf actory precision for measurement of total body fat, fat-free mass, and total body bone mineral could be demonstrated in vivo and in vitro. P redictions of lean body mass in humans on the basis of DEXA, total bod y water, and total body potassium were significantly different. The re sults of multiple regression analysis suggested that a component of to tal body water was related to body potassium, and another component wa s predicted by body fat. In addition, extracellular fluid volume, as m easured by the bromide space technique, was significantly associated w ith both fat-free mass and fat mass as measured by DEXA. These finding s have implications for the interpretation of body composition data in humans.