Association between arterial stiffness and the deformability of red blood cells (RBCs).

The relationship between the flexibility of atherosclerotic vessels and RBC deformability has been investigated. A significant difference of RBC deformability was found among the arterial stiffness groups classified by oscillometric measurement of blood pressure. The deformability was determined by direct microscopic observation of RBCs subjected to shear stress of 0.3 to 40.0 Pa with a rotating rheoscope. The deformability of stiffen group - abnormal pulse wave pattern group or moderate cardiovascular risk group - was found to be much higher than that of normal groups in wide shear stress region (3.0, 10.0, 30.0, and 40.0 Pa). We postulate that the body adapts high shear stress in vivo by making RBCs more distensible, and therefore less likely to rupture under strain or microcirculatory alterations.