Extracellular resistance is sensitive to tissue sodium status; implications for bioimpedance-derived fluid volume parameters in chronic kidney diseaseCitation formats

  • External authors:
  • Nicos Mitsides
  • Agnieszka Swiecicka
  • Roshni Mitra

Standard

Extracellular resistance is sensitive to tissue sodium status; implications for bioimpedance-derived fluid volume parameters in chronic kidney disease. / Mitsides, Nicos; Mchugh, Damien; Swiecicka, Agnieszka; Mitra, Roshni; Brenchley, Paul; Parker, Geoff J. M.; Mitra, Sandip.

In: Journal of Nephrology, 2019, p. 1-9.

Research output: Contribution to journalArticlepeer-review

Harvard

APA

Vancouver

Author

Bibtex

@article{f9043da1508246069b850f7ac734fb9c,
title = "Extracellular resistance is sensitive to tissue sodium status; implications for bioimpedance-derived fluid volume parameters in chronic kidney disease",
abstract = "Multifrequency bioimpedance spectroscopy (BIS) is an established method for assessing fluid status in chronic kidney disease (CKD). However, the technique is lacking in predictive value and accuracy. BIS algorithms assume constant tissue resistivity, which may vary with changing tissue ionic sodium concentration (Na+). This may introduce significant inaccuracies to BIS outputs. To investigate this, we used 23Na magnetic resonance imaging (MRI) to measure Na+ in muscle and subcutaneous tissues of 10 healthy controls (HC) and 20 patients with CKD 5 (not on dialysis). The extracellular (Re) and intracellular (Ri) resistance, tissue capacitance, extracellular (ECW) and total body water (TBW) were measured using BIS. Tissue water content was assessed using proton density-weighted MRI with fat suppression. BIS-derived volume indices were comparable in the two groups (OH: HC − 0.4 ± 0.9 L vs. CKD 0.5 ± 1.9 L, p = 0.13). However, CKD patients had higher Na+ (HC 21.2 ± 3.0, CKD 25.3 ± 7.4 mmol/L; p = 0.04) and significantly lower Re (HC 693 ± 93.6, CKD 609 ± 74.3 Ohms; p = 0.01); Ri and capacitance did not vary. Na+ showed a significant inverse linear relationship to Re (rs = − 0.598, p < 0.01) but not Ri. This relationship of Re (y) and Na+ (x) is described through equation y = − 7.39x + 814. A 20% increase in tissue ionic Na+ is likely to overestimate ECW by 1.2–2.4L. Tissue Na+ concentration has a significant inverse linear relationship to Re. BIS algorithms to account for this effect could improve prediction accuracy of bioimpedance derived fluid status in CKD.",
keywords = "bioimpedance, Sodium, CKD",
author = "Nicos Mitsides and Damien Mchugh and Agnieszka Swiecicka and Roshni Mitra and Paul Brenchley and Parker, {Geoff J. M.} and Sandip Mitra",
year = "2019",
doi = "10.1007/s40620-019-00620-3",
language = "English",
pages = "1--9",
journal = "Journal of Nephrology",
issn = "1121-8428",
publisher = "Wichtig",

}

RIS

TY - JOUR

T1 - Extracellular resistance is sensitive to tissue sodium status; implications for bioimpedance-derived fluid volume parameters in chronic kidney disease

AU - Mitsides, Nicos

AU - Mchugh, Damien

AU - Swiecicka, Agnieszka

AU - Mitra, Roshni

AU - Brenchley, Paul

AU - Parker, Geoff J. M.

AU - Mitra, Sandip

PY - 2019

Y1 - 2019

N2 - Multifrequency bioimpedance spectroscopy (BIS) is an established method for assessing fluid status in chronic kidney disease (CKD). However, the technique is lacking in predictive value and accuracy. BIS algorithms assume constant tissue resistivity, which may vary with changing tissue ionic sodium concentration (Na+). This may introduce significant inaccuracies to BIS outputs. To investigate this, we used 23Na magnetic resonance imaging (MRI) to measure Na+ in muscle and subcutaneous tissues of 10 healthy controls (HC) and 20 patients with CKD 5 (not on dialysis). The extracellular (Re) and intracellular (Ri) resistance, tissue capacitance, extracellular (ECW) and total body water (TBW) were measured using BIS. Tissue water content was assessed using proton density-weighted MRI with fat suppression. BIS-derived volume indices were comparable in the two groups (OH: HC − 0.4 ± 0.9 L vs. CKD 0.5 ± 1.9 L, p = 0.13). However, CKD patients had higher Na+ (HC 21.2 ± 3.0, CKD 25.3 ± 7.4 mmol/L; p = 0.04) and significantly lower Re (HC 693 ± 93.6, CKD 609 ± 74.3 Ohms; p = 0.01); Ri and capacitance did not vary. Na+ showed a significant inverse linear relationship to Re (rs = − 0.598, p < 0.01) but not Ri. This relationship of Re (y) and Na+ (x) is described through equation y = − 7.39x + 814. A 20% increase in tissue ionic Na+ is likely to overestimate ECW by 1.2–2.4L. Tissue Na+ concentration has a significant inverse linear relationship to Re. BIS algorithms to account for this effect could improve prediction accuracy of bioimpedance derived fluid status in CKD.

AB - Multifrequency bioimpedance spectroscopy (BIS) is an established method for assessing fluid status in chronic kidney disease (CKD). However, the technique is lacking in predictive value and accuracy. BIS algorithms assume constant tissue resistivity, which may vary with changing tissue ionic sodium concentration (Na+). This may introduce significant inaccuracies to BIS outputs. To investigate this, we used 23Na magnetic resonance imaging (MRI) to measure Na+ in muscle and subcutaneous tissues of 10 healthy controls (HC) and 20 patients with CKD 5 (not on dialysis). The extracellular (Re) and intracellular (Ri) resistance, tissue capacitance, extracellular (ECW) and total body water (TBW) were measured using BIS. Tissue water content was assessed using proton density-weighted MRI with fat suppression. BIS-derived volume indices were comparable in the two groups (OH: HC − 0.4 ± 0.9 L vs. CKD 0.5 ± 1.9 L, p = 0.13). However, CKD patients had higher Na+ (HC 21.2 ± 3.0, CKD 25.3 ± 7.4 mmol/L; p = 0.04) and significantly lower Re (HC 693 ± 93.6, CKD 609 ± 74.3 Ohms; p = 0.01); Ri and capacitance did not vary. Na+ showed a significant inverse linear relationship to Re (rs = − 0.598, p < 0.01) but not Ri. This relationship of Re (y) and Na+ (x) is described through equation y = − 7.39x + 814. A 20% increase in tissue ionic Na+ is likely to overestimate ECW by 1.2–2.4L. Tissue Na+ concentration has a significant inverse linear relationship to Re. BIS algorithms to account for this effect could improve prediction accuracy of bioimpedance derived fluid status in CKD.

KW - bioimpedance

KW - Sodium

KW - CKD

U2 - 10.1007/s40620-019-00620-3

DO - 10.1007/s40620-019-00620-3

M3 - Article

SP - 1

EP - 9

JO - Journal of Nephrology

JF - Journal of Nephrology

SN - 1121-8428

ER -