DISTRIBUTION OF THE BIOELECTRICAL IMPEDANCE VECTOR IN BRAZILIAN FREE-LIVING ELDERLY SUBJECTS
K. Pfrimer, A.V.B. Margutti, I.A. Leme, J.S. Camelo Jr, J.C. Moriguti, N.K.C. Lima, J.S. Marchini, E. Ferriolli
J Aging Res Clin Practice 2014;3(1):7-13
Objectives: The calculation of body composition using bioelectrical impedance analysis is limited in the elderly because most equations have been found to be inadequate. Bioelectrical impedance vector analysis (BIVA) is a new method that is used for the routine monitoring of the variation in body fluids and nutritional status. The aim of the present study was to determine bivariate tolerance intervals of the whole-body impedance vector and to describe phase angle (PA) values for healthy urban-living elderly aged 60-70 years. Design: This descriptive cross-sectional study. Setting: Ribeirão Preto, São Paulo, Brazil. Participants: Healthy free living elderly. Measurements: General and anthropometric data and bioelectrical impedance data (800µA–50kHz) were obtained. Bivariate vector analysis was conducted with resistance-reactance (RXc) graph method. The BIVA software was used to construct the graphs. Results: Ninety-eight elderly persons (59.1% females) who were healthy, independent and aged 60 to 70 years old were studied. We constructed standard RXc-score graph and RXc-tolerance ellipses (50, 75 and 95%) that can be used in any analyses. Mean PA was 5.47 (SD 0.67)° for men and 5.0 (SD 0.59)° for women. Different ellipses were defined for men and women because there are differences in the body composition according to gender. Conclusion: The graphs differ from those previously reported in the literature, due to ethnic differences in body composition. BIVA and PA allow nutritional assessment and eliminate the prediction errors of conventional impedance formulas.
K. Pfrimer ; A.V.B. Margutti ; I.A. Leme ; J.S. Camelo Jr ; J.C. Moriguti ; N.K.C. Lima ; J.S. Marchini ; E. Ferriolli (2014): DISTRIBUTION OF THE BIOELECTRICAL IMPEDANCE VECTOR IN BRAZILIAN FREE-LIVING ELDERLY SUBJECTS . The Journal of Aging Research and Clinical Practice (JARCP). http://dx.doi.org/10.14283/jarcp.2014.2