[Assessment of body composition by bioelectrical impedance analysis: effects of skin resistance on impedance].

Effects of skin resistance on impedance values were studied in order to propose reliable determination of body composition in human. Analysis of the data indicated that impedance values (Z = (R2 + Xc2)0.5) varied considerably in the following conditions: 1) 230 +/- 97.8 ohms when electrodes were directly attached; 2) 490 +/- 52.5 ohms when electrodes were attached immediately after use of alcohol; 3) 584 +/- 44.1 ohms when electrodes were attached immediately after use of alcohol with electrode gel; and 4) 589 +/- 45.0 ohms when electrodes were attached in the order of elimination of skin resistance----use of alcohol----use of electrode gel. We suggest that impedance obtained by the bioelectrical impedance analysis should be measured immediately after elimination of skin resistance at least with electrode gel.