Ma. Flynn et al., COMPARISON OF BODY-COMPOSITION MEASURED BY TOTAL-BODY POTASSIUM AND INFRARED INTERACTANCE, Journal of the American College of Nutrition, 14(6), 1995, pp. 652-655
Objective: The purpose of this study was to find how closely a near in
frared instrument (IRI), Futrex 5000, would compare to whole body coun
ting (WBC) of potassium-40 (K-40) in assessing body composition. Desig
n: We measured lean body mass (LBM) and percent total body fat (PCF) i
n 177 males and 27 females by total body potassium (TBK) and by infrar
ed interactamce (IRI). TBK was assessed by 2 pi whole body counter (WB
C) and IRI by Futrex (F) instrument. These subjects were measured for
TBK and for IRI within 1 week of each other. Result: A large mean diff
erence (p less than or equal to 0.001) was found between the results u
sing the two instruments: IRI data for LBM were higher and PCF lower c
ompared to TBK. Conclusion: As shown by repeated TBK measurements over
a 22-year period in these same volunteers, this technique is reliable
. The IRI assessments did not come to a close fit with TBK.