Epidemiologic findings on blood viscosity

Abstract

In order to obtain basic knowledge about blood viscosity, which is changed by a variety of factors and disease, this study examined variations in blood viscosity. Sex, age, season, smoking, blood pressure, vibration syndrome, various diseases and exposure to cold were considered.Blood viscosity levels in several groups were measured with a cone-plate viscometer. The groups consisted of male and female healthy non-smokers among hospital employees, male inhabitans of a mountain village, male subjects with the vibration syndrome found in union shop forestry workers, pulp manufacturing company employees and male and female hospitalized patients.The following results were obtained:1) In healthy non-smokers, there were no significant variations in whole-blood viscosity and plasma viscosity with regard to age and season, but whole-blood viscosity levels in males were significantly higher than those in females, at all shear rates. A significant positive correlation was observed beetween whole-blood viscosity and Ht.2) In an analysis of the influence of smoking, hypertension and vibration syndrome on whole-blood viscosity, three way experimental lay out, smoking, hypertension and vibration syndrome were all found to increase whole-blood viscosity. An interaction between smoking and hypertension was demonstrated which increased whole-blood viscosity. Morever, the same analysis carried out for plasma viscosity, demonstrated that the factors which increased plasma viscosity were again smoking and hypertension.3) Whole-blood viscosity values in healthy non-smokers before exposure to cold showed lower values than in smokers and hypertensives, morever, whole-blood viscosity levels during exposure to cold in healthy non-smokers increased greatly compared to those in smokers and hypertensives.4) Whole-blood viscosity levels during exposure to cold in non-hypertensives with vibration syndrome increased greatly, but whole-blood viscosity values in hypertensives with vibration syndrome did not increase. Whole-blood viscosity values in hypertensives with vibration syndrome were already high before exposure to cold.5) With regard to cold exposure, blood viscosity changes in subjects with or without vibration syndrome showed a similar tendency in both the exposed and non-exposed arms.6) Whole-blood viscosity values in myocardial infarction, essential hypertension and diabetes mellitus were increased, and those in collagen disease and anemia were decreased. Plasma viscosity in myocardial infarction, coronary arteriosclerosis, cerebral infarction, essential hypertension, collagen disease and diabetes mellitus were increased, and those in anemia were decreased.