It has been reported that dyslipidemia is associated with rheological and microcirculatory abnormalities in patients with ischaemic heart disease. However, it is not known how this system changes in men and women with ageing. In healthy young and middle‐aged subjects the following parameters were evaluated: total plasma cholesterol, triglycerides and HDL‐cholesterol levels, deformability of erythrocytes, red blood cell and platelet aggregations, blood and plasma viscosity, neutrophils' cytosolic [Ca
$^{2+}]\tsub{i}$
and microviscosity of the bilayer's total lipid phase and the annular near‐protein zone of the membranes. Using intravital computer‐associated microscopic system we investigated the microcirculation of bulbar conjunctiva. Oxygen transfer characteristics were measured with a Radiometer TCM2 monitor. It is evident from the data obtained that in men of middle age the total plasma cholesterol and triglyceride levels are higher in comparison with other groups. The rheological behavior of red blood cell and platelet aggregations in men differ from that in women. Neutrophils activation in healthy subjects was not recorded. Our results show that changes of the blood rheological properties of men 35–50 years old can lead to disturbances of the microcirculation.
