Erythropoietin requirement in patients with type 2 diabetes mellitus on maintenance hemodialysis therapy.

Diabetes is known to be a risk factor for the severity of anemia in non-dialyzed patients with renal failure. The aim of this study was to evaluate differences in hemoglobin (Hb) response to erythropoietin (EPO) in diabetic and nondiabetic patients on chronic hemodialysis (CHD). Sixty-four patients on CHD were included in the study: 24 type 2 diabetics (mean age, 59+/-11 years; 10 men, 14 women) and 40 nondiabetics (age, 53+/-14 years; 21 men, 19 women). All patients received a fixed dose of 50 mg ferric saccharate and EPO per week, dosed individually to achieve a target Hb level of 12 g/dl. Hb levels, ferritin, transferrin saturation (TSAT), EPO requirement (IU/kg/week), folic acid, vitamin B12 and C-reactive protein (CRP) were measured every two months. Additionally, the incidence of infectious diseases during the observation period of six months was evaluated, and a univariate correlation analysis of CRP and EPO requirements was performed in both groups. Patients with and without diabetes were divided into two groups each: those with normal CRP and those with elevated CRP. The EPO requirements of these groups were compared. Under identical iron substitution the mean Hb level increased more, but not significantly, in non-diabetic patients than in diabetic patients. After 6 months the mean Hb levels were 12.1+/-1.2 versus 11.5+/-1.2 g/dl (NS), although the actual EPO requirement was higher in diabetic than in non-diabetic subjects (244+/-122 versus 183+/-118 IU/kg/week; p<0.05). CRP after 6 months was significantly higher in diabetic than in non-diabetic patients (2.6+/-2.2 versus 1.5+/-1.3 mg/dl; p<0.05), as was the incidence of infectious disease (n/patient/month) (0.24 versus 0.08; p<0.05). The correlation coefficient between CRP and EPO requirements was statistically significant in both diabetic (r=0.547 p<0.01) and non-diabetic subjects (r=0.577; p<0.001). All other laboratory indices were similar in both groups. In the diabetic patients with normal CRP (n=6) the Hb levels achieved after six months were similar to those of non-diabetic patients (n=10) with normal CRP (11.9+/-1.1 versus 12.1+/-1.2%), and the required EPO was comparable. We conclude that the Hb response to EPO is reduced in diabetic patients on CHD. This elevated EPO requirement may be explained by a greater prevalence of infectious diseases, characterized by a significantly higher CRP level, in these patients. Other causes for the elevated EPO requirement could be excluded.