Metabolic effects of erythropoietin in patients on peritoneal dialysis

Insulin and lipid metabolism were studied in seven patients (19+/-1 years) with end-stage renal disease on continuous cycling peritoneal dialysis (CCPD) before and after 6 months of therapy with human recombinant erythropoietin (EPO) to correct anemia. Hematocrit increased from 22.2+/-1.8% to 34.8+/-1.8% (P<0.001) following EPO treatment. Serum ferritin (P<0.05) and serum iron (P<0.01) decreased significantly after anemia correction. There were no significant differences in the height, weight, anthropometric measures, or intakes of protein and total calories in the patients before and after the 6 months of EPO therapy. There were no differences in serum biochemical parameters, including 1,25-dihydroxyvitamin D3 and parathyroid hormone in these patients before and after 6 months of EPO therapy. Residual renal function and Kt/Vurea were also not different before and after 6 months of EPO therapy. The hyperinsulinemic euglycemic clamp technique was used to measure insulin sensitivity. Before EPO, insulin sensitivity was low in patients on CCPD (238+/-19 mg/m2 per min) compared with controls (320+/-30; P<0.01). After 6 months of EPO therapy, insulin sensitivity increased by 28% (305+/-26, P<0.01 vs. pre-EPO values), so that these values were no longer different from control values. The hyperglycemic clamp technique was used to measure insulin secretion. Before EPO, both early- and late-phase insulin secretion were elevated in patients on CCPD compared with controls (P<0.01 in both cases). These indices of insulin secretion decreased significantly (P<0.01) following 6 months of EPO. Before EPO, plasma triglycerides, total cholesterol, low-density lipoprotein, cholesterol, and apolipoprotein B were elevated in patients compared with controls. These lipid concentrations decreased significantly following 6 months of EPO. Thus, treatment of anemia by EPO is associated with improvements in insulin and lipid abnormalities in uremic patients on CCPD.