Selected Applications of Bioelectrical Impedance Analysis: Body Fluids, Blood Volume, Body Cell Mass and Fat Mass

Combined protein and calcium β-hydroxy-β-methylbutyrate induced gains in leg fat free mass: a double-blinded, placebo-controlled study

“…We have previously shown that segmental BIS can provide accurate estimates of arm and leg muscle volume compared to limb volume measurements using MRI [41]. Because segmental measurements for estimating FFM reflect more closely the underlying biophysical model of BIS to whole-body BIS (assumption of isotropic conductor with homogeneous cross-sectional area and consistent proportions specific tissues), we expected segmental measurements to be more accurate and precise than whole-body FFM estimations [27,28,31]. The methodological difference between single slice recordings and total limb estimations in tracking changes in segmental hypertrophy may also explain the lack of detecting an ergogenic effect associated with HMB supplementation in two very recent studies, employing similar study designs [20,22].…”

“…Bioelectric impedance spectroscopy (BIS) was performed with a SEAC SFB3 multifrequency phase-sensitive bioelectrical impedance monitor (Impedimed, Eight Mile Plains, Qld, Australia) via a tetrapolar electrode arrangement following standard procedures that have been previously described in detail [27]. Briefly, current introducing electrodes (2.0 cm × 2.0 cm, Impedimed Inc., Carlsbad, CA, USA) were placed on the dorsal surface of the right hand and foot just below the metacarpalphalangeal and metatarsal-phalangeal joints, respectively.…”

“…Subsequently, whole-body fluid volumes were derived on the basis of the Hanai equation [30], and considering differences in limb and trunk geometry. Specific details of the methodology are provided by Stahn et al [27,31]. For the computation of total body water (TBW), the second-generation mixture theory equation was employed [32].…”

Tissue Composition Changes and Secondary Lymphedema

“…29 While BIS has been suggested for use only in the early stages of lymphedema, 30 the water in adipose tissue is also likely to be detectable by BIS. 31 However, the low-moderate correlation of BIS to fat ratio indicates that this is not a linear relationship. The severity of lymphedema failed to predict differences in inter-limb fat volumes.…”

Body composition analysis in older adults with dementia. Anthropometry and bioelectrical impedance analysis: a critical review

“…44 BIA BIA, besides presenting the advantages of the anthropometry (simplicity, safety, cost-effectiveness and so on), does not require either specialized personnel for its implementation or active patient collaboration, so that the measurement error is lower than that of anthropometrics, provided that it is correctly performed. Under ideal conditions, the variation for repeated measurements of bioimpedance during a single testing session has been reported to be o 1%, 45 overall reproducibility is 2.7-4.0% and prediction errors for FFM and TBW were estimated to be 3.5-6% and 3-8%, respectively. 46 A great review of fundamentals and applications of this method has recently been published by Lukaski; 47 briefly, BIA is based on the principle that the various body components offer a different resistance to the passage of an electrical current, 47,48 and there are two different ways to interpret the bioelectrical measures (resistance, R; and reactance, Xc) in terms of BC: translating bioimpedance measures into body volumes and masses (that is, conventional BIA), and generating the impedance vector by using the R and Xc obtained at a frequency of 50 kHz, to match it against that of the healthy reference population (that is, Bioelectrical Impedance Vector Analysis, BIVA).…”