[Early erythropoietin deficiency in diabetic kidney lesion]

To evaluate the renal production of erythropoietin (EPO) in relation to filtration function in patients with diabetic kidney lesion.

The investigation enrolled 183 patients with types 1 and 2 diabetes mellitus (DM), of whom 128 were diagnosed as having diabetic kidney lesion. Serum EPO levels were measured by enzyme immunoassay. Patients who had a glomerular filtration rate (GFR) of below 15 ml/min/1.73 m2 and received erythropoiesis-stimulating agents were excluded from the investigation.

The mean serum EPO levels in the patients with diabetic kidney lesion did not vary with the presence or absence of anemia, the degree of albuminuria, or GFR. A physiological inverse relationship was found between the level of EPO and that of hemoglobin in the blood of the patients with DM without kidney disease and in those with renal lesion and GFR > or = 60 ml/min/1.73 m2. The magnitude of the association of the values increased as GFR was higher. The level of EPO was found to be unassociated with hemoglobin in patients with GFR < 60 ml/min/1.73 m2.

In the patients with diabetic kidney lesion, serum EPO concentrations did not depend on the stage of chronic kidney disease and the degree of albuminuria in spite of more severe anemia as renal failure progressed. These patients showed inadequate EPO production just in early diminished renal filtration function.