BODY-COMPOSITION METHODS IN THE ELDERLY - A CRITICAL ANALYSIS

The objective of this study was to compare the values obtained for tot al body fat obtained with deuterium dilution, anthropometry and bioimp edance in 41 institutionalized elderly individuals (65-90 years old). The values obtained with each technique were compared using the graphi c analysis proposed by Bland and Altman, that plots the difference bet ween measurements with both methods against their average. In men (n = 20) and women (n = 21), the best degree of agreement was obtained bet ween the values measured by deuterium dilution and those calculated fr om skinfolds (mean difference = 1.4% and 6.9%, respectively). The limi ts of agreement (+/- 2SD), for skinfolds reached a maximum of 14.8% in men, and 16.8% in women. These values tend to underestimate fat in th e obese and overestimate it in thinner subjects. For bioimpedance and deuterium dilution, the inter-method difference is significantly great er: 9.3% in men and 14.7% in women. This lack of agreement is attribut ed to the fact that the bioimpedance equipment utilizes equations vali dated for younger adults. In conclusions, estimation of body compositi on using skinfolds has the smallest difference compared to deuterium d ilution, eventhough individual measurements are not clinically accepta ble. Caution is recommended when using measurements of body compositio n in the elderly, due to large errors in the determinations.