Pressor effect of recombinant human erythropoietin: results of ambulatory blood pressure monitoring and home blood pressure measurements.

We investigated whether treatment of anemic hemodialysis patients with a low dose of recombinant human erythropoietin (erythropoietin) for a short period would increase their blood pressure. Ambulatory blood pressure monitoring and home blood pressure measurements were used to detect minute increase in blood pressure. Thirty-two patients with a hematocrit of 25% or less received erythropoietin at the dose of 4500 IU/week, by the intravenous route for 8 weeks. Erythropoietin increased the hematocrit from 20.9 +/- 2.1 to 26.2 +/- 2.1%. Erythropoietin elevated mean ambulatory blood pressure by 5 mmHg or more in two-thirds of patients (n = 20; pressor group), while it elevated home mean blood pressure by 5 mmHg or more in one-third of patients (n = 11). An increase in clinic mean blood pressure by more than 5 mmHg was observed only in one-fourth of patients (n = 7). Circadian variation of blood pressure (nocturnal fall and diurnal rise) had been attenuated in the patients of the pressor group before erythropoietin treatment and erythropoietin decreased the nocturnal fall of blood pressure further more. Erythropoietin elevated nocturnal blood pressure more than diurnal blood pressure. Therefore, the increase in blood pressure induced by erythropoietin was detected more reliably by ambulatory blood pressure monitoring. There was no relation between the change in hemoglobin concentration and the increase in ambulatory blood pressure induced by erythropoietin. Erythropoietin tended to decrease cardiac output and plasma volume while it increased total peripheral resistance. It also decreased plasma norepinephrine and vasopressin levels but did not affect other humoral factors. Although the pressor effect of erythropoietin treatment for 8 weeks at the dose of 4500 IU/week was not evident on clinic blood pressure measurements, any increase in blood pressure determined by ambulatory blood pressure should be treated carefully to reduce the risk of a cardiovascular complication in patients receiving hemodialysis.