Prior studies support the use of BIA in assessing healthy
adult body composition. As there are recognized age-related
body composition and physiological changes that alter tissue
conduction, concern arises for BIA validity in the elderly. The
present study evaluated the validity of a leg-to-leg contact
electrode BIA system (TBF-305, Tanita Corp., Tokyo, Japan)
in an elderly cohort by comparing BIA fat estimates with
those by DXA.
There were 74 subjects with mean age 64 yrs. and BMI (26.6±4.8
kg/m²) who successfully completed protocol.
The mean % fat estimates by BIA (32.8±9.5) and DXA
(33.7±9.9) were not significantly different (p=0.58).
Linear regression demonstrated a high correlation between
BIA and DXA fat estimates (r=0.9, p<0.001, SEE=4.4). The
slope and intercept of the regression line were not significantly
different from 1 and zero, respectively. These results suggest
that the leg-to-leg BIA system reliably predicts body fat
in elderly subjects.