Normocytic normochromic anemia due to automatic neuropathy in type 2 diabetic patients without severe nephropathy: a possible role of microangiopathy

We describe here four male patients with long-term and poorly controlled type 2 diabetes mellitus. They shared many common characteristic complications, such as severe autonomic neuropathy, proliferative retinopathy and normocytic normochromic anemia without progressive renal failure and macroangiopathy. They also showed normal levels of erythropoietin and reticulocyte, which was considered relatively low. The coefficient of variation of R–R, a useful method to estimate autonomic failure, showed markedly advanced autonomic neuropathy in all four patients. Coronary angiography did not reveal stenosis, anomaly or collateral vessels, but left ventriclography showed diffuse or partial hypokinesis. Massive proteinuria, high urinary levels of N-acetyl-β-d-glucosamidase (NAG) and β₂-microglobulin (β₂M) were detected, though creatinine clearance (Ccr) was not so deteriorated. Treatment with recombinant erythropoietin increased their hemoglobin and hematocrit levels. These common points have a possibility to be brought about by tubulointerstitial damage and microangiopathy may be involved in it.