Affiliations: Laboratory of Clinical Hemorheology, Hospital of Sesto San Giovanni, Via Matteotti 83, Sesto San Giovanni 20099, Milan, Italy | Department of Biophysics, Shanghai Medical University, Shanghai 200032, China
Abstract: Attention has been paid to the relationship between hypertension and hemorheology by several authors and their results showed that hypertension was associated with altered blood viscosity. The previous reports were empirically from one or several points of blood viscosity under different shear rates. Can we consider the pathogenesis from the whole curve of blood viscosity versus shear rate? Our aims are to use new concepts to reveal hemorheological properties and to analyze the pathological changes for essential hypertension by a Casson equation which summarize the whole curve of blood viscosity versus various shear rate. We use two parameters which are derived from Casson equation and regressed from all the data of shear stress and shear rate, i. e. Casson yield stress and Casson viscosity, to describe the hemorheological changes for 139 cases of hypertension patients. Our results showed that: 1) The total patients show increase of the two Casson parameters, especially for female patients; 2) Essential hypertension in the early stage may be not closely connected to Casson parameters; 3) When essential hypertension begins to complicate with cerebral and coronary heart diseases, or some other diseases, the patients show remarked changes in the two Casson parameters, especially for Casson yield stress; 4) Yield stress may be the best parameter to show abnormality in hemorheology, and Casson viscosity is also good to show the abnormality in hemorheology; 5) Yield stress and Casson viscosity are proportionally correlated to hematocrit and plasma viscosity, especially for the yield stress.
