Dependency of Whole Blood Viscosity and Plasma Viscosity on Electrolytes and Lipids - An in Vitro Study

Blood viscosity is a crucial hemodynamic biomarker because it determines the friction against blood vessels, the quantity of oxygen that is delivered to organs and tissues, and the degree of exertion by the heart. Many factors affect blood viscosity, either directly or inversely. e.g., fibrinogen and hematocrit. The effect of other factors (e.g., cholesterol) on blood viscosity is still under investigation. The aim of this study is to evaluate the effect of both electrolytes [sodium (Na), calcium (Ca), and potassium (K)] and lipids [triglycerides (TGs), lowdensity lipoprotein (LDL), and high-density lipoprotein (HDL)] on both whole blood viscosity (WBV) and plasma viscosity (PV). WBV was measured by rotational viscosity at high and low shear rates. PV was measured using a rotational viscometer at a single shear rate. A strong correlation of WBV and PV with Ca was found. TGs had an effect on WBV at a low shear rate. LDL and HDL were correlated directly with both WBV and PV. The observed relationships can be explained as a direct effect of both electrolytes and lipids on PV. On the other hand, the relationship between WBV and both electrolytes and lipids can be explained indirectly, namely through the effect of lipids and electrolytes on red blood cell aggregation and deformation. Index Term-Blood Viscosity, Plasma viscosity, Electrolytes,