Lipid and apolipoprotein patterns during erythropoietin therapy: roles of erythropoietin, route of administration, and diet

Abstract

Background: Long-term effects of rHuEpo on the blood lipid profile have not been well documented. The aim of this paper is to prospectively evaluate whether rHuEpo therapy affects lipid metabolism, and whether these effects are influenced by changes in dietary habits and by route of rHuEpo administration.

Methods: The study was performed in 33 maintenance haemodialysis patients (MHP) treated for one year with rHuEpo either intravenously (n = 15) or subcutaneously (n = 18), three times per week at the end of each dialysis session. The doses were 50 IU/kg intravenously or 35 IU/kg subcutaneously during the first 6 months and 20 IU/kg during the following months. The control group consisted of 17 MHP not treated with rHuEpo. Total cholesterol, LDL-cholesterol and HDL-cholesterol, triglycerides, apolipoproteins Al and B, haemoglobin, serum albumin, blood urea nitrogen, serum creatinine, Kt/V, protein catabolic rate, and plasma erythropoietin were assessed at months 0, 2, 4, 6, 9, 12 and 2 weeks after rHuEpo discontinuation. Changes in food intake were evaluated on the basis of weekly dietary diaries before, and 3 and 9 months after treatment. Patients were divided into two groups: group A consisted of 19 patients who showed an increase in their energy intake (10% or more of basal value), and group B was formed by 14 patients without or with slight changes in their food intake. After the 6th month, dialysis schedules were adapted to new protein catabolic rate values in patients who increased their food intake.

Results: During follow-up, there were no significant changes in any of the parameters in the control group. In group A, blood urea nitrogen, serum creatinine, protein catabolic rate, cholesterol, LDL cholesterol, triglycerides and apolipoprotein B increased significantly since the first months of rHuEpo treatment, and changes in cholesterol and apolipoprotein B correlated significantly with changes in protein catabolic rate. In group B, cholesterol, LDL cholesterol, and apolipoprotein B decreased significantly after the 6th month of treatment, without changes in blood urea nitrogen, serum creatinine and protein catabolic rate values. In both groups A and B, HDL cholesterol decreased significantly until the 6th month and returned to basal values in the following months and apolipoprotein Al decreased until the 4th month and rose to levels higher than basal values in the following months. First rHuEpo administration and rHuEpo suspension at end of follow-up did not show any acute effect on lipid profile, despite significant changes in plasma erythropoietin values. Changes in lipid profile were similar with intravenous and subcutaneous administration of rHuEpo.

Conclusions: We infer that long-term rHuEpo treatment positively affects the lipid profile, but in some patients who show exaggerated increase in their food intake these effects may be balanced and overcome by increment in some atherogenic blood lipid fractions. The changes in lipid and apolipoprotein patterns during rHuEpo therapy are not influenced by route of rHuEpo administration.