Erythropoietin depletion and anaemia in diabetes mellitus.

Objective: To discover whether Type 1 diabetic patients with autonomic neuropathy might be anaemic and erythropoietin (EPO)-depleted.

Methods: Fifteen Type 1 diabetic patients with serious complications (DM-COMP) were selected because of severe symptomatic autonomic neuropathy, including significant postural hypotension. All had proteinuria from nephropathy (three microalbuminuria and 12 macroalbuminuria), but a normal serum creatinine (< 122 micromol/l). They were compared to age and duration matched Type 1 diabetic controls without autonomic neuropathy (DM-controls) and non-diabetic patients with and without hypochromic, microcytic anaemia.

Results: The DM-COMP patients were anaemic (mean haemoglobin (Hb) 11.1+/-1.2 g/dl), sometimes severely (minimum Hb 9.2 g/dl), compared to non-neuropathic DM-controls (Hb 13.7+/-0.7 g/dl; P < 0.001). Furthermore, EPO failed to increase in association with anaemia in the DM-COMP group compared to the progressive increase in the non-diabetic, anaemic patients (difference of regression lines P < 0.001), indicating EPO depletion in the anaemic, diabetic patients. There was no other demonstrable cause for the anaemia. Treatment with EPO in 5 DM-COMP patients led to a rapid increase in haemoglobin (range 1.7-5.0 g/dl) with improvement in wellbeing.

Conclusions: Some Type 1 diabetic patients with autonomic neuropathy present with an EPO-depleted anaemia, which responds to treatment with EPO. This observation supports the concept of autonomic neuropathy as a cause of anaemia with EPO depletion, although the role of established renal damage cannot be excluded.