Abstract
To assess whether the viscoelastic properties of whole blood might be influenced by age, gender, cigarette smoking and oral contraceptives, we measured viscoelasticity of whole blood and plasma at different shear rates in healthy adult subjects. Thirty-five male and forty female subjects were classified into ten groups and their viscoelastic data were evaluated. Viscoelasticity of whole blood (shear rates 10/s and 50/s), viscosity of plasma (shear rate 10/s), aggregation index, shear resistance and flexibility index of erythrocytes and density hematocrit were measured with an oscillating capillary rheometer and densitymeter.
Age was found to increase whole blood elasticity significantly at low shear rates when young male non- smokers were compared with old non-smokers of both sexes. The intake of oral contraceptives was found to increase whole blood elasticity at high shear rates when young non-smoking men were compared with young non-smoking women who had taken oral contraceptives for at least one year. Concerning shear resistance of aggregated erythrocytes, the values of young non-smoking men were significantly lower than the values of all other groups except the group of young smoking women who had not taken oral contraceptives. Density hematocrit was higher in men than in women. Whole blood and plasma viscosities as well as aggregation and flexibility indices were not significantly different when ten groups were compared by analysis of variance.