Leg electrical resistance predicts venous blood viscosity and hematocrit

Issue title: SPECIAL SECTION: Selected Papers of the Joint Conference of the ESCHM-ISCH-ISB-2018, 2-6 July, 2018, Krakow, Poland

Article type: Research Article

Authors: Varlet-Marie, Emmanuelle^{a; b} | Vachoud, Laurent^c | Marion, Bénédicte^{a; b} | Roques, Céline^{a; b} | Fidani, Thibault^d | Chevalier, Constance^d | Mercier, Jacques^d | Raynaud de Mauverger, Eric^d | Brun, Jean-Frédéric^{d; *}

Affiliations: [a] Institut des Biomolécules Max Mousseron (IBMM) UMR 5247 CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, France | [b] Laboratoire de Biophysique & Bio-Analyses, Faculté de Pharmacie, Université de Montpellier, France | [c] UMR QualiSud, Faculté de Pharmacie, Université de Montpellier, France | [d] U1046 INSERM, UMR 9214 CNRS «Physiopathologie & Médecine Expérimentale du Coeur et des Muscles – PHYMEDEXP», Unité d’Explorations Métaboliques (CERAMM), Université de Montpellier, Département de Physiologie Clinique, Hôpital Lapeyronie CHRU Montpellier, France

Correspondence: [*] Corresponding author: Jean-Frédéric Brun, U1046 INSERM, UMR 9214 CNRS «Physiopathologie & Médecine Expérimentale du Coeur et des Muscles – PHYMEDEXP», Unité d’Explorations Métaboliques (CERAMM), Université de Montpellier, Département de Physiologie Clinique, Hôpital Lapeyronie CHRU Montpellier, France. E-mail: [email protected].

Abstract:  We previously reported that whole body bioelectrical impedance analysis (BIA) measurements are correlated to some hemorheologic factors, suggesting a relationship between viscosity factors and electric properties of flowing blood not only in vitro but also in vivo. Recently we reported that with segmental BIA (analyzing the body considered as composed of 5 cylinders) predictive equations for various determinants of blood viscosity were closer than for the wole body. Another widely used BIA technique uses leg-to-leg impedance measurements so that two cylinders (the two legs) are analyzed. We investigated whether impedance measured with this technique (Tanita TBF-300) is also a predictor of blood viscosity factors. From viscometric measurements performed on venous blood drawn in recreative athletes over the range of shear rates 1 to 6000 s–1 (RHEOMETRE Anton Paar CP 50-1), we found a correlation between leg-leg resistance at 50 kHz (Rx[50 kHz]) and blood viscosity at 1000 s–1 (η1000= 0.0051 Rx[50 kHz] + 1.3265; r = 0.521 p = 0.028 yielding a prediction of η1000 (Bland Altman plot: bias 0.05 [RANGE – 0.24; 0.34]. Neither plasma viscosity nor the red cell rheology index «k» of Quemada’s model are correlated with Rx[50 kHz], but hematocrit (Hct) does (Hct (%) = 0.0217 Rx[50 kHz] + 33.783; r = 0.480 p = 0.044) yielding a prediction of Hct (Bland Altman plot: bias – 0.11, [range – 1.67; 1.45]. The discrepancy between actual and predicted Hct is also correlated with resistance at 50 kHz (r = 0.575 p = 0.031) as does the discrepancy between actual and predicted Hct/viscosity ratio (r = –0.651 p = 0.006). Therefore, as other previously studied methods, leg to leg BIA predicts viscosity, suggesting that blood rheology may influence the passage of an electric current in the legs.

Keywords: Segmental bioelectrical impedance, hematocrit, Myrenne aggregometer, Red blood cell aggregation, electrical conductance, light transmission

DOI: 10.3233/CH-199003

Journal: Clinical Hemorheology and Microcirculation, vol. 71, no. 4, pp. 397-402, 2019