Use of total-body electrical conductivity for the assessment of body composition in middle-aged and elderly individuals.
Body composition was predicted for 114 middle-aged and elderly individuals aged 35-90 y by using total-body electrical conductivity (TOBEC), densitometry, and hydrometry. Highly significant correlations were achieved between the TOBEC Phase value and fat-free mass (FFM) determined by densitometry (FFMd) and hydrometry (FFMdw) with values ranging from 0.713 to 0.981. TOBEC predicted FFM (FFMT) was consistently higher than either FFMd or FFMdw for both men and women in all age groups. A theoretical calculation of percent body fat was performed with a three-component model with body density, total body water, and bone mineral content. The recalculation of fat was used to estimate a new FFM (FFMnew). These calculations resulted in a decrease in fat and an increase in FFMnew. Because the TOBEC signal is unaffected by bone mineralization, FFMT may provide a more accurate estimation of body composition than do FFMd or FFMdw in this group of individuals.
Van Loan
M D
MD
US Department of Agriculture, Wesern Human Nutrition Research Center, San Francisco, CA.
Koehler
L S
LS
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001823:Body Composition; D003720:Densitometry; D004553:Electric Conductivity; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D008875:Middle Aged