Laboratoire de Biophysique and Bio-Analyses, Faculté de Pharmacie, Université Montpellier I, France.
Clin Hemorheol Microcirc. 2011;47(2):151-61. doi: 10.3233/CH-2010-1378.
Bioelectrical impedancemetry (BIA) has been used to evaluate hemorheological parameters in vitro, and whole body impedance measurements are also correlated to some hemorheologic factors, due to their close relationship with determinants of electric properties of blood. In previous studies, we have determined a set of predictive equations for hematocrit, whole blood viscosity and plasma viscosity in both sedentary and trained individuals. Recent developments of the interpretation of BIA analysis based on Hanai's mixture conductivity theory allows a more interpretative analysis of the relationships between these electric measurements and body composition. Impedance can be analyzed in terms of resistance and resistivity of the whole body and even more, assuming some simplifications, resistance R and resistivity ρ of total body water (TBW), extracellular water (ECW) and intracellular water (ICW). In this study we thus investigated relationships between blood rheology and these calculations of R and ρ in a sample of 83 subjects (age: 9-64 yr; BMI: 17-44 kg/m(2)). BIA was performed with a multifrequency bioelectrical impedancemeter using low intensity at the following frequencies: 1, 5, 10, 50 and 100 kHz. Viscometric measurements were done with a falling ball viscometer. Hematocrit was measured with microcentrifuge. We found a new prediction of Quemada's viscometric index of RBC rigidity "k" which was positively correlated to the resistance of ECW (R(e)) and even more if it was related to this volume: k = 0.005809 R(e)/ECW + 1.1784 (r = 0.487; Bland-Altman mean difference: 0.0124; range: -0.00481 to 0.00296). A new finding was that red blood cells (RBC) aggregability, that in the previous studies was not related to whole body impedance, despite its in vitro measurability with such measurements, was correlated to extracellular resistance and resistivity. The Myrenne index "M" was negatively correlated to the resistivity of the extracellular fluid ρe and is predicted by: M = -27.4755 ρ(e) + 1121.57029 (r = 0.463; Bland-Altman mean difference: 0.00194; range: -0.842 to 0.842). Furthermore, the SEFAM index "S(10)" is correlated to the ρe and is predicted by S(10) = -59.38579 (ρ(e)-40) + 63.083 (r = 0.761; Bland-Altman mean difference: 0.000722; range: -1.77 to 1.77). Therefore, a more in-depth analysis of electric properties of the body provides a closer approach of RBC rheology, although, of course, most remains to be understood in this intriguing domain.
生物电阻抗分析（BIA）已被用于评估体外血液流变学参数，全身阻抗测量也与一些血液流变学因素相关，因为它们与血液的电特性决定因素密切相关。在以前的研究中，我们已经为久坐和训练有素的个体确定了一组预测红细胞压积、全血粘度和血浆粘度的方程。基于 Hanai 混合电导率理论的 BIA 分析解释的最新发展允许对这些电测量与身体成分之间的关系进行更具解释性的分析。可以根据全身的电阻和电阻率来分析阻抗，甚至可以进一步假设一些简化，即全身总水量（TBW）、细胞外液（ECW）和细胞内液（ICW）的电阻 R 和电阻率 ρ。在这项研究中，我们在 83 名受试者（年龄：9-64 岁；BMI：17-44kg/m²）的样本中研究了血液流变学与这些 R 和 ρ 计算之间的关系。BIA 是使用低强度在以下频率下使用多频生物电阻抗仪进行的：1、5、10、50 和 100kHz。使用落球粘度计进行粘度测量。红细胞压积用微离心机测量。我们发现了 Quemada 的 RBC 刚性粘度指数“k”的新预测值，该值与 ECW 的电阻（R(e)）呈正相关，如果与该体积相关，相关性甚至更强：k = 0.005809 R(e)/ECW + 1.1784（r = 0.487；Bland-Altman 平均差异：0.0124；范围：-0.00481 至 0.00296）。一个新的发现是，红细胞（RBC）聚集性在以前的研究中与全身阻抗没有关系，尽管可以通过这种测量方法在体外进行测量，但与细胞外电阻和电阻率相关。Myrenne 指数“M”与细胞外液 ρe 的电阻率呈负相关，可通过以下公式预测：M = -27.4755 ρ(e) + 1121.57029（r = 0.463；Bland-Altman 平均差异：0.00194；范围：-0.842 至 0.842）。此外，SEFAM 指数“S(10)”与 ρe 相关，可通过 S(10) = -59.38579 (ρ(e)-40) + 63.083 进行预测（r = 0.761；Bland-Altman 平均差异：0.000722；范围：-1.77 至 1.77）。因此，对身体的电特性进行更深入的分析提供了一种更接近 RBC 流变学的方法，尽管在这个令人着迷的领域中，仍有许多问题需要了解。
