Proximal electrode placement improves the estimation of body composition in obese and lean elderly during segmental bioelectrical impedance analysis

摘要: Bioelectrical impedance analysis (BIA) is an affordable, non-invasive, easy-to-operate, and fast alternative method to assess body composition. However, BIA tends overestimate the percent fat (%BF) in lean elderly underestimate %BF obese people. This study examined whether proximal electrode placement eliminates this problem. Forty-two men women (64-96 years) who had a wide range of BMI [22.4 +/- 3.3 kg/m(2) (mean SD), 16.8-33.9 kg/m(2)] (11.3-44.8%) participated study. Using (2)H (18)O dilutions as criterion for measuring total water (TBW), we compared various placements; wrist-to-ankle, arm-to-arm, leg-to-leg, elbow-to-knee, five- nine-segment models, combination distal (wrists or ankles) (elbows knees) electrodes. TBW was most strongly correlated with square height divided by between knees elbows (H(2)/Z (proximal); r = 0.965, P < 0.001). In five-segment observed systematic errors associated (P 0.05). After including ratio segments (P/D) independent variable, none methods showed any bias against %BF. addition, all were able estimate more accurately (e.g., wrist-to-ankle model, from R(2) 0.90, SEE 1.69 kg 0.94, 1.30 kg). The results suggest that using electrodes alone subjects, while improve accuracy composition measurements.