Hematocrit, plasma protein, plasma volume, and viscosity in early hypertensive disease

Abstract

Two groups of male subjects of the same age, one with early hypertensive disease and the other normotensive without heart disease, were studied before, during, and after moderate exercise (600 k.p.m./min.). It was found that the hypertensive subjects at rest had significantly higher hematocrit and whole blood viscosity, slightly higher plasma protein, and slightly lower plasma volume than the normal subjects. During exercise, a significant increase in hematocrit and whole blood viscosity was found in both groups. The plasma protein level increased and the plasma volume decreased significantly in the hypertensive group. It is suggested that there is an increased leakage of plasma water into the extravascular space in the hypertensive subjects, with a decrease in plasma volume and increase in hematocrit, viscosity, and plasma protein level.