Predictive accuracy of BIA equations for estimating fat-free mass of black men.
This study assessed the predictive accuracy of previously published bioelectrical impedence analysis (BIA) equations in estimating the fat-free mass (FFM) of black men, 19 to 50 years. The reference method was hydrostatic weighing (HW) at residual lung volume. Body density (Db) was converted to relative body fat (%BF) for calculation of FFMHW using the Schutte et al. equation. Resistance and reactance were measured with a Valhalla bioimpedance analyzer. Age-specific, generalized, and fatness-specific BIA equations were cross validated using regression analysis. The Segal fatness-specific equations were modified using a method recommended by Stolarczyk. All of the equations significantly (P < 0.05) underestimated the average reference measure of FFMHW. However, the underestimation of FFM for the modified Segal fatness-specific equation was relatively small (-1.8 kg) and not likely to have much clinical significance. Furthermore, this equation had a high correlation with reference FFMHW (ry,y' = 0.97), low prediction errors (SEE = 2.1 kg; E = 2.7 kg), and accurately estimated the FFM within +/- 3.5 kg for 78% of the individuals in the sample. Thus, we recommend using the modified fatness-specific BIA equation for estimating the FFM of black men.
Wagner
D R
DR
Center for Exercise and Applied Human Physiology, University of New Mexico, Albuquerque 87131, USA. drwags@unm.edu
Heyward
V H
VH
Kocina
P S
PS
Stolarczyk
L M
LM
Wilson
W L
WL
D000328:Adult; D044383:Black People; D001823:Body Composition; D003720:Densitometry; D017097:Electric Impedance; D006801:Humans; D008297:Male; D008432:Mathematical Computing; D008875:Middle Aged; D015203:Reproducibility of Results