Anemia in patients of diabetic kidney disease

Anemia is the major complication resulting from chronic kidney disease (CKD) and also a risk factor for cardiovascular events and a poor quality of life (QoL). Diabetic kidney disease (DKD) is the major cause of CKD. Initially, insulin resistance has been reported to increase erythropoiesis, but it might be a minor issue. DKD-related anemia developed earlier and was more severe than non-DKD-related anemia based on more complicated mechanisms, including greater bleeding tendency associated with antiplatelet effect, less O2 sensing due to autonomic neuropathy or renin-angiotensin-aldosterone system inhibitor use, inhibitory effect of inflammatory cytokines, urinary loss of erythropoietin (EPO), and poor response to EPO. In DKD patients, prompt correction of anemia allows for a better cardiovascular outcome and QoL, which are similar to the promising effect of anemia correction in CKD patients. However, current evidence recommended that the avoidance of a high or normalized hemoglobin (Hb) level has been suggested in the treatment of anemia in DKD patients. Despite that EPO has a pleotropic effect on renal protection from animal studies, the renal benefit was less evident in CKD and DKD patients. Recently, the antidiabetic agent, sodium glucose cotransporter-2 inhibitors (SGLT2i), has been reported to exhibit the renal benefits due to the tubulo-glomerular feedback in addition to sugar control. It may also be due to less renal ischemic through higher EPO levels, followed by higher Hb levels. More studies are needed to clarify the link between the renal benefit of SGLT2i and EPO production.