Body Composition Estimation and Agreement Analysis Between Bipolar and Tetrapolar Bioelectrical Impedance Analyzers

The aim of this study was to analyze the body composition estimation and agreement of the measurements produced from two bioelectrical impedance analysers in young adult men. Twenty-two apparently healthy subjects (23.6 +/- 2.9 yrs; 73.0 (+/-) 6.8 kg; 177.6 +/- 6.0 cm; 23.1 +/- 1.9 kg/m(2)), were submitted to bioelectrical impedance measurements by tetra-polar whole body (TWB, Biodynamic Body Composition Analyser, model 310) and bipolar for upper body (BUB, OMRON (TM), model HBF-306BL) after 12 h fast. Relative body fat (%BF), lean body mass (LBM) and fat mass (FM) estimation were established from information supplied by two analysers. No significant difference was verified for %BF (10.9 +/- 4.3 vs. 10.0 +/- 4.2%; P = 0.09), FM (8.1 +/- 3.5 vs. 7.4 +/- 3.5 kg; P = 0.10) or LBM (64.9 +/- 5.2 vs. 65.5 +/- 4.9 kg; P = 0.09) between TWB and BUB, respectively. Positive significant correlations (P < 0.001) were found between both analysers for LBM (r = 0.948), FM (r = 0.891) and %BF (r = 0.859). The agreement thresholds were -0.6 +/- 3.2 kg for LBM (r = 0.135; P = 0.551), 0.8 +/- 4.5% for %BF (r = 0.050; P = 0.824), and 0.6 +/- 3.2 kg for FM (r = 0.032; P = 0.886). The results suggest that the body composition estimation by bioelectrical impedance does not seem to be affected by use of different analysers (BUB vs. TWB) or the total body adiposity.