Low plasma erythropoeitin (EPO) is a key causal factor in the anaemia of diabetic patients. The aim of this study was to investigate the prevalence of anaemia in relation to EPO in patients with Type 2 diabetes.Methods
In a clinic-based cross-sectional study of 161 Type 2 diabetes patients, we measured EPO, ferritin and full blood count. The patients were classified on the basis of the urine albumin:creatinine excretion ratio as normo-, micro- or macroalbuminuric. Serum creatinine, cystatin C and glomerular filtration rate (GFR) calculated from cystatin C were used as markers of renal function. All the patients were assessed for symptoms and signs of diabetic complications, including diabetic peripheral sensory neuropathy (PSN).Results
Twenty-one (13.0%) patients were anaemic; 80 patients (49.7%) had low EPO (< 5 mU/ml), of whom 28.8% had a GFR < 60 ml/min per 1.73 m2; 57.5% were normoalbuminuric, 33.7% were microalbuminuric and 8.8% macroalbuminuric. Although EPO was significantly higher in anaemic patients compared with non-anaemic patients, the EPO response was inappropriate for the degree of anaemia. Of patients with PSN, 66.7% had low EPO but there was no significant difference in EPO between patients with and without PSN. Log EPO correlated significantly with urine microalbumin:creatinine ratio and logistic regression analysis showed that haemoglobin, age and urine microalbumin: creatinine ratio were the main determinants of EPO.Conclusions
The degree of microalbuminuria is the most significant determinant of plasma EPO, which is often low or inappropriately normal in diabetic patients with and without anaemia.