Bioelectrical impedance vector analysis and body composition in cervical spinal cord injury: A pilot study

Abstract

IntroductionBody composition assessment in cervical spinal cord injury (c-SCI) individuals is important to monitor the fat free-mass (FFM) loss, due to immobilization, or gain, due to exercise practice. Single frequency bioelectrical impedance analysis (SF-BIA) is low in cost, simple and easy.ObjectivesThe aims of this study are: to evaluate the concordance between the FFM values obtained using dual X-ray absorptiometry (DXA) and the three SF-BIA previous predictive equations; and to test the applicability of the bioelectrical impedance vector analysis (BIVA).MethodsTwenty-three c-SCI males were divided into two groups: Physically active (PA; n = 13; at least 150 min/week) and non-active individuals (NPA) and were assessed by DXA and SF-BIA simultaneously.ResultsFFM values were similar between groups PA and NPA. Considering all participants, FFM values obtained by Kocina and Heyward (>11%) and Sun (<15.4%) predictive equations were different when compared to DXA (p < 0.01). However, Buchholz's et al. predictive equation showed FFM values similar to DXA, but presented poor concordance (<7%, p = 0.99; concordance coefficient = 0.85). BIVA showed consistency in ellipse distribution using FFM obtained using Buchholz et al. predictive equation.ConclusionsThe use of non-specific BIA equations can lead to misinterpretation in FFM values in male c-SCI individuals. Predictive equations for this group need to be developed.

Phase Angle and Bioelectrical Impedance Vector Analysis (BIVA) in Amyotrophic Lateral Sclerosis (ALS) Patients

“…BIVA tolerance ellipses interpretation stands that an abnormal situation is indicated when the experimental data falls outside the 95th percentile ellipsis; a high body cell mass is suggested when the data are positioned above the long axis of the ellipsis; and hypohydration is inferred when the data appears to the right of the short axis of the ellipsis. The TBW shows an inverse relationship with the length of the impedance vector, and the combination of this vector's length and direction is referred to as the PhA [25].…”