Endocrine Abstracts

Anemia occurs early and predicts high risk of cardiovascular events and death in patients with diabetic nephropathy (DN). It may result from various factors including erythropoietin (EPO) deficiency, iron and vitamin deficiencies, systemic inflammation, adverse effects of some drugs and others. However, the clinical significance of each factor is not fully known. The aim of this study was to assess the relative contribution of EPO deficiency, iron deficiency and systemic inflammation as pathogenetic factors of anemia development in patients with early stages of DN.

We investigated 72 anemic patients with type 2 diabetes mellitus and chronic kidney disease (CKD) stages 1–3. GFR was calculated by Cockcroft-Gault formula. Anemia was defined according to World Health Organization criteria (2008). Serum levels of EPO, ferritin, vitamin B12, interleukin 1β (IL1β), IL6 and tumor necrosis factor-α (TNF-α) were measured by immunoassay (Labsystems MR 600 analyser).

EPO deficiency was in found in 48.6%, low serum ferritin levels – in 11.1%, low vitamin B12 levels – in 2.8% of patients. Most individuals had elevated levels of at least one of the proinflammatory cytokines (IL1β, 73.6%; IL6, 54.2%; TNF-α, 33.3%). The contribution of these factors varied depending on the degree of renal impairment. EPO deficiency was found in 20.8, 45.8 and 79.2% patients with CKD stages 1, 2 and 3 respectively. The prevalence of iron deficiency was 16.6, 12.5 and 4.2% in patients with CKD stages 1, 2 and 3 respectively.

The results of the study suggest that pathogenesis of anemia in patients with early stages of DN is multifactorial. The most prevalent pathogenetic factors are EPO deficiency and systemic inflammation. The role of EPO deficiency increases and the role of iron deficiency decreases with progression of DN.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.