Erythropoietin and cardiovascular risk

We studied the changes in some cardiovascular risk (CVR) factors in 24 maintenance hemodialysis patients treated for 1 year with recombinant human erythropoietin (rHuEPO) either intravenously (12 cases) or subcutaneously (12 cases). In order to clarify whether changes in some parameters were due to direct action of rHuEPO or to changes in food intake, we divided the patients into two groups: group A was formed by 14 patients who showed an increase in their food intake during rHuEPO therapy and group B by 10 patients without or with slight changes in their food intake. rHuEPO induced an improvement in well-being in 20 of 24 patients and in physical working capacity in 14 of 24, an increase in mean blood pressure in all patients, and hypertension in 4 of 24 patients. The incidence of hypertension was slightly higher after intravenous (3/12) than after subcutaneous (1/12) treatment. The rate of dialysis treatment with symptomatic hypertension significantly decreased from 44.0 +/- 8.0 to 12.1 +/- 2.2% after intravenous and from 41.3 +/- 6.8 to 10.0 +/- 3.8% after subcutaneous treatment. Evaluation of glucose metabolism (intravenous glucose tolerance test) before and after 3 months of rHuEPO therapy showed an improvement in glucose utilization (insulin resistance reduction). Cholesterol (CH), low-density lipoprotein CH, triglycerides, and apolipoprotein B significantly increased in group A, but not in group B. Both in groups A and B, high-density lipoprotein CH significantly decreased during the first 6 months and returned to basal values during the following months, and the apolipoprotein A1 level significantly decreased during the first 4 months and increased to levels higher than basal values during the following months. Changes in CH and apolipoprotein B were also positively correlated with changes in the protein catabolic rate. We infer that rHuEPO has opposite effects on CVR, but subcutaneous administration, dietary control, and antihypertensive treatment may produce a net decrease in CVR of maintenance hemodialysis patients on rHuEPO therapy.