Distribution of bioelectrical impedance vector values in multi-ethnic infants and pre-school children

Bioelectrical Impedance of Vectorial Analysis and Phase Angle in Adolescents

“…Tanabe et al [39] compared Brazilian children with European children and also found that they were different. This might suggest that our study population is different from those in other studies, therefore justifying the need for studies in different countries and populations.…”

Body composition assessment in the infant

“…The former assumption is poorly upheld in infancy; as mentioned above, body water compartments and the FFM hydration are undergoing rapid changes during infancy here that affect fluid distribution and electrolyte concentrations between the intra- and extracellular compartments, making estimates of body composition obtained from BIA imprecise for the first few years of life (Margutti et al, 2010; Savino et al, 2003). For these and other reasons, BIA body composition equations tend to have poor performance across different ethnic groups and populations (Dehghan and Merchant, 2008), including in infants (Tanabe et al, 2012). For instance, FM and percent FM from total body electrical conductivity (TOBEC), a whole-body variant of BIA no longer commercially available (Hashimoto et al, 2002), and from BIA using existing equations (Sen et al, 2010) had poor correlation with estimates from isotope dilution.…”

“…Alternatively, if the target of investigation is infant body fluid level or nutritional status (e.g., in tracking infants with protein-energy malnutrition), and a qualitative or semi-quantitative determination is sufficient, methods such as bioelectrical impedance vector analysis (BIVA) (as in (Tanabe et al, 2012) are useful. BIVA uses R and X c values (both adjusted for length) directly from the instrument (Piccoli et al, 1994), without reliance on any assumptions about their relationship to FFM.…”

Impedance of tissue-mimicking phantom material under compression

“…The relaxation time constant, τ R , is defined as the ratio of the viscosity and the elastic modulus as (6) leading to a concise expression of the model: .…”

“…From the analysis of single cells (1) and cultures (2) to tissues (3) and organs (4) to whole bodies (5) and across populations (6), bioelectrical impedance has proven its value in quantifying physiology time and again. While the spatial scale of the samples ranges from cell membranes to human populations, the temporal range is not nearly as robust.…”