Evaluation of hemorheological parameters and red cell morphology in hypertension.

The aim of our study was to evaluate hemorheological parameters in two groups of patients both suffering from essential hypertension compared with an homologous group of subjects not suffering from hypertension; the 1st group was composed of 16 patients (8 females and 8 males, mean age 65.6 +/- 16.5) suffering from essential hypertension; the 2nd one of 26 patients (8 females and 18 males, mean age 74.3 +/- 11.7) suffering from essential hypertension and cerebral or cardiac ischemia in a chronic phase. The group of controls was composed of 20 subjects (mean age 50.5 +/- 11.5). In all these subjects we evaluated: blood viscosity, hematocrit, plasmatic fibrinogen, red cell morphology according to Zipursky-Forconi method and blood pressure. Our results show that blood viscosity and fibrinogen were statistically increased relative to controls. Comparison between these groups leads us to observe that blood viscosity and fibrinogen are slightly higher in the first group in a statistically significant way (7.5 +/- 1.1 cPs 10 s(-1) 1st group, 7.9 +/- 1.05 cPs 10 s(-1) 2nd group; 362.2 +/- 167.3 mg% 1st group, 384.6 +/- 106.9 mg% 2nd group). Blood pressure was higher in the second group. The study of red cell morphology in all the patients showed a prevalence in the percentage of discocytes, cells which have less deformability compared to bowls. The study demonstrated EMI (Erythrocyte Morphology Index) decreased in a statistically significant way compared to controls (0.70 +/- 0.03 1st group; 0.65 +/- 0.02 2nd group; 1.2 +/- 0.09 control group). In subjects suffering from essential hypertension with end-organ damage EMI further decreases. So we observed that hypertension is also delineated by the increase in the discocytes percentage which results in reduction of the red cell deformability. In conclusion, when hypertension causes end-organ damage, the hemorheological alterations, which implicate a worsening in microcirculation, are more evident.