Determination of resistance at zero and infinite frequencies in bioimpedance spectroscopy for assessment of body composition in babies

Natalia Pinheiro de Castro; Tamiris Ramos; Patricia Helen de Carvalho Rondó; Leigh C Ward

doi:10.1088/1361-6579/ad3dc0

Determination of resistance at zero and infinite frequencies in bioimpedance spectroscopy for assessment of body composition in babies

Physiol Meas. 2024 Apr 11. doi: 10.1088/1361-6579/ad3dc0. Online ahead of print.

Authors

Natalia Pinheiro de Castro¹, Tamiris Ramos¹, Patricia Helen de Carvalho Rondó¹, Leigh C Ward²

Affiliations

¹ Nutrition Department, University of Sao Paulo, School of Public Health, Sao Paulo, 05508-900, BRAZIL.
² Department of Biochemistry, University of Queensland, Brisbane, QLD 4072, Brisbane, QLD 4069, AUSTRALIA.

PMID: 38604189
DOI: 10.1088/1361-6579/ad3dc0

Abstract

Bioimpedance spectroscopy (BIS) is a popular technique for the assessment of body composition in children and adults but has not found extensive use in babies and infants. This due primarily to technical difficulties of measurement in these groups. Although improvements in data modelling have, in part, mitigated this issue, the problem continues to yield unacceptably high rates of poor quality data. This study investigated an alternative data modelling procedure obviating issues associated with BIS measurements in babies and infants.ApproachBIS data are conventionally analysed according to the Cole model describing the impedance response of body tissues to an applied AC current. This approach is susceptible to errors due to capacitive leakage errors of measurement at high frequency. The alternative is to model BIS data based on the resistance-frequency spectrum rather than the reactance-resistance Cole model thereby avoiding capacitive error impacts upon reactance measurements.Main resultsThe resistance-frequency approach allowed analysis of 100% of data files obtained from BIS measurements in 72 babies compared to 87% successful analyses with the Cole model. Resistance-frequency modelling error (percentage standard error of the estimate) was half that of the Cole method. Estimated resistances at zero and infinite frequency were used to predict body composition. Resistance-based prediction of fat-free mass (FFM) exhibited a 30% improvement in the two-standard deviation limits of agreement with reference FFM measured by air displacement plethysmography when compared to Cole model-based predictions.SignificanceThis study has demonstrated improvement in the analysis of BIS data based on the resistance frequency response rather than conventional Cole modelling. This approach is recommended for use where BIS data are compromised by high frequency capacitive leakage errors such as those obtained in babies and infants.&#xD.

Keywords: Babies and infants; Bioimpedance spectroscopy; Body composition; Cole Model; Resistance-frequency model.

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