Novel Iron Parameters in Patients with Type 2 Diabetes Mellitus in Relation to Kidney Function

Background/aims: Anemia of chronic disease is a common feature in diabetes and chronic kidney disease. Hepcidin is the key element involved in iron metabolism; however, studies on new indices of iron status are still ongoing. The aim of the study was to assess novel iron parameters in patients with type 2 diabetes mellitus in relation to kidney function. Methods: The study included 80 type 2 diabetic patients and 23 healthy volunteers. Standard laboratory measurements were used to measure the iron status, complete blood count, creatinine, the estimated glomerular filtration rate (eGFR), serum lipids, and brain natriuretic peptides (BNPs). Commercially available kits were used to measure hepcidin-25, the soluble transferrin receptor (sTfR), growth differentiation factor-15 (GDF-15), and hypoxia-inducible factor-1 alpha. Results: Anemia was present in 65% of the studied patients. The control group was found to have significantly higher hepcidin, sTfR, and GDF-15, and lower hemoglobin and iron. When compared with patients with eGFR values ≥60 mL/min/1.73 m(2) and <60 mL/min/1.73 m(2), we found that patients with higher eGFR had higher hemoglobin, ferritin, and HIF-1 alpha, lower BNP, and were younger. We found that levels of HIF-1 alpha are negligible in the studied population and were related to age only in patients with eGFR values ≥60 mL/min/1.73 m(2). Conclusion: A comprehensive assessment of iron status is rarely performed. Novel biomarkers of iron metabolism are not generally related to kidney function. Whether the assessment of HIF-1 alpha would be a marker of efficient anemia therapy with HIF-prolyl hydroxylase inhibitors is still a matter for further study.