Hemorrheological indices, catecholamines, neuropeptide Y and serotonin in patients with essential hypertension.

Hemorrheological and humoral abnormalities and excessive platelet activity can predict the development of cardiovascular complications in patients with essential hypertension. A study was conducted to assess the influence of gender on these factors and the interrelations between changes in hemorrheology and the sympatho-adrenal system in 54 patients (18 women, 36 men) with essential hypertension (aged 39.6 +/- 9.7 years) and 25 healthy volunteers (10 women, 15 men; aged 36.0 +/- 7.2 years). A decrease in erythrocyte deformability (p < 0.01) was found in the hypertensive men compared with the hypertensive women. Hematocrit (p < 0.01), blood viscosity at the shear rates of 0.3 s-1 (p < 0.01) and 6 s-1 (p < 0.01), plasma viscosity (p < 0.01), erythrocyte aggregation (p < 0.01), and neuropeptide Y (p < 0.02) concentrations were higher in the hypertensive men than in the hypertensive women. A positive correlation between blood fibrinogen and serotonin was found in the pooled hypertensive group and in the hypertensive men (p < 0.01) and between blood viscosity (shear rate 6 s-1) and neuropeptide Y in the pooled hypertensive group (p < 0.01). Neuropeptide Y correlated with filtration time of 1 mL blood in the hypertensive men (p < 0.05) and in the pooled normotensive group (p < 0.01) and with beta-thromboglobulin in the hypertensive women (p < 0.001). A positive correlation was also found in the hypertensive men between erythrocyte and platelet aggregation (p < 0.01) and between beta-thromboglobulin and adrenaline (p < 0.01). Hemorrheological and humoral abnormalities are more pronounced in men than in women with essential hypertension and may contribute to the increased incidence of cardiovascular events in men.