Journal of Applied Physiology, Vol 72, Issue 6 2181-2187, Copyright © 1992 by American Physiological Society
Use of bioelectrical impedance to assess body composition changes at high altitude
C. S. Fulco, R. W. Hoyt, C. J. Baker-Fulco, J. Gonzalez and A. Cymerman
US Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760-5007.
This study determined the feasibility of using bioelectrical impedance
analysis (BIA) to assess body composition alterations associated with body
weight (BW) loss at high altitude. The BIA method was also evaluated
relative to anthropometric assessments. Height, BW, BIA, skinfold (SF, 6
sites), and circumference (CIR, 5 sites) measurements were obtained from 16
males (23-35 yr) before, during, and after 16 days of residence at
3,700-4,300 m. Hydrostatic weighings (HW) were performed pre- and
postaltitude. Results of 13 previously derived prediction equations using
various combinations of height, BW, age, BIA, SF, or CIR measurements as
independent variables to predict fat-free mass (FFM), fat mass (FM), and
percent body fat (%Fat) were compared with HW. Mean BW decreased from 84.74
to 78.84 kg (P less than 0.01). As determined by HW, FFM decreased by 2.44
kg (P less than 0.01), FM by 3.46 kg (P less than 0.01), and %Fat by 3.02%
(P less than 0.01). The BIA and SF methods overestimated the loss in FFM
and underestimated the losses in FM and %Fat (P less than 0.01). Only the
equations utilizing the CIR measurements did not differ from HW values for
changes in FFM, FM, and %Fat. It was concluded that the BIA and SF methods
were not acceptable for assessing body composition changes at altitude.
