Iron deficiency in CKD

• Iron deficiency arising from multiple factors directly or indirectly related to kidney dysfunction.
• Dietary intake of iron inadequate due to poor appetite or advice to consume a low-protein diet, 
• Possibly exacerbated by chronic iron loss from repeated intestinal bleeding resulting from CKD-related abnormal platelet function. 
• The chronic inflammatory status of many CKD patients induces increased hepcidin synthesis, which in turn inhibits uptake of dietary iron by enterocytes and export of iron from enterocytes, macrophages, and storage cells. 
• These effects restrict the availability of iron for hemoglobin synthesis and other functions. 
• In patients undergoing hemodialysis, regular blood loss compounds these problems, but even in nondialysis CKD (ND-CKD), iron is estimated to affect over half of all adults with CKD Stage 3 or 4.
• Prevalent in CKD patients receiving treatment with an erythropoiesis-stimulating agent (ESA) due to the marked increase in the demand for iron, and is a major cause of nonresponsiveness to ESA therapy with associated negative implications for anemia correction and healthcare costs

Target

• a minimum serum ferritin level above 100 ng/ mL 
• a minimum transferrin saturation (TSAT) greater than 20% in ESA-treated CKD patients

References:
http://www.ncbi.nlm.nih.gov/pubmed/23314137