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Updated: May 29, 2026
Evaluation of Fluid Overload by Bioelectrical Impedance Vectorial Analysis
Published on: August 17, 2022
Distribution of bioelectrical impedance vector values in multi-ethnic infants and pre-school children
Roberta Falcão Tanabe1, Zina Maria Almeida de Azevedo, Vania Matos Fonseca
1Intensive Care Unit, Pediatrics Department, Fernandes Figueira Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil. robertaftanabe@gmail.com
Insights
Bioimpedance measurements in Brazilian children show ethnic variations. Defining country-specific reference values for total body impedance is crucial due to diverse ethnic backgrounds.
Area of Science:
- Pediatric Bioimpedance Analysis
- Human Physiology
- Body Composition Assessment
Background:
- Bioimpedance values can be influenced by ethnicity.
- Establishing ethnic-specific reference data is essential for accurate health assessments.
Purpose of the Study:
- To measure the total body impedance vector in Brazilian infants and pre-school children.
- To compare these bioimpedance values with data from other countries.
Main Methods:
- Utilized the RXc graph method (tetrapolar analysis at 50 kHz) on 255 healthy Brazilian children (1-36 months).
- Plotted 95%, 75%, and 50% tolerance ellipses by age group to analyze impedance vector migration.
Main Results:
- Observed progressive increases in reactance and decreases in resistance with age.
- Demonstrated significant differences between the mean bioimpedance vectors of Brazilian children and European children of similar age ranges.
Conclusions:
- Emphasizes the necessity of country-specific reference values for total body impedance vectors.
- Highlights the impact of ethnic diversity on bioimpedance measurements, necessitating localized data.
Background & Aims:
Ethnicity may influence bioimpedance values. The goal of this study was to measure total body impedance vector in infants and pre-school children in Brazil and compare them with those reported in other countries.
Methods:
We analyzed bioelectrical impedance from a sample of 255 healthy Brazilian children, aged 1-36 months, using the RXc graph method (tetrapolar analysis at 50 kHz frequency). The 95%, 75% and 50% tolerance ellipses were plotted by age group.
Results:
The mean impedance vector showed migration across age groups, with progressive higher reactances and lower resistances as age increased. The mean bioimpedance vectors from the present sample of Brazilian children were different from those of European children of the same age ranges.
Conclusions:
Our results confirm the importance of defining reference values of total body impedance vector for each country in view of the considerable ethnic diversity among different geographical areas.
