In this study we researched the prevalence of hypertension in 197 patients with polycythemia vera and in 500 hematologically healthy patients who were randomly selected.

Patients with polycythemia vera therein showed with 152.4 +/- 26.2 // 93.3+/- 15.9 mmHg clearly higher average values of blood pressure than the control group with 139.0 +/- 25.0 // 85.0 +/- 5 mmHg (p<0.001).

Furthermore, the patients with polycythemia vera showed a clearly higher prevalence of hypertension than the control patients. So we demonstrated hypertension (RR>/= 160 and/or 95 mmHg) in about a third of the patients (30.5%) with polycythemia vera, whereas the 500 control patients showed only in 17% of the cases elevated values of blood pressure. Moreover, about half of the patients with polycythemia vera (44.2%) showed blood pressure values elevated to borderline, whereas in the control group we found a borderline hypertension in only 28.4% of the cases.

The analysis of different age groups yielded the further result that patients with polycythemia vera demonstrated a clearly higher prevalence of hypertension than the control group in all age groups except one (61 to 70 years old patients). Both groups of patients showed here an increasing prevalence of hypertension with increasing age. Comparable differences between cases of polycythemia vera and control patients were observed for borderline values of blood pressure.

As expected, the polycythemia vera patients showed in a statistically significant way higher values concerning hemoglobin concentration, erythrocytes, hematocrit, leucocytes and thrombocytes than average patients (p<0.001). Furthermore we were able to demonstrate in the control group, but specially in the patients with polycythemia vera, a statistically highly significant relation between the diastolic blood pressure and the hemoglobin concentration (p<0.001 resp. p<0.01). A similar relation also resulted in both patient groups between diastolic blood pressure and hematocrit (p<0.05 resp. p<0.01).

Our results demonstrate therefore that patients with polycythemia vera show a clearly higher prevalence of hypertension than the control patients. Our findings furthermore support the assumption that the pathologically increased erythropoesis plays an essential role in the pathogenesis of elevated blood pressure in these polycythemia vera patients.