Advances in Iron Deficiency Management in Chronic Kidney Disease: Insights into Pathophysiology, Diagnosis, and Therapeutic Approaches

Background: Iron deficiency is very common and is clinically significant in patients with chronic kidney disease (CKD). It contributes to anemia and adversely affects outcomes in these patients, including quality of life, and survival. For all the advancements in our understanding of iron metabolism, the optimal methods for treating deficiency in patients with CKD continue to be an area of active research. Objective: The focus of this review is to describe the advances in the pathophysiology, diagnosis, and management of iron deficiency in CKD, emphasizing its biomarker value and the efficacy of oral versus intravenous (IV) iron supplementation. Methods: One hundred twenty patients with chronic kidney disease (stage 3 to 5) suffering from anemia due to iron deficiency were included in this prospective, observational study. They were assigned to either Group A (mild to moderate iron deficiency anemia [IDA], n=60) or Group B (severe IDA, n=60), according to the severity of iron deficiency. Group A received oral iron supplementation, whereas Group B received IV iron therapy. Various parameters on lab tests were measured (initial and after the treatment duration of 8 weeks) for assessment: serum ferritin, transferrin saturation (TSAT), soluble transferrin receptor (sTfR), and serum hepcidin levels. The primary outcome was change in hemoglobin levels, whereas change in iron biomarkers counted as secondary outcomes. Results: The efficacy of IV iron therapy was superior to oral iron supplementation in increasing hemoglobin concentrations and iron parameters (p<0.05). In Group B, the mean increase in hemoglobin concentration was 2.3 g/dL, along with impressive data regarding serum ferritin, TSAT, and sTfR. Elevation in hepcidin levels was significant in severe iron deficiency, indicating that less iron was available for erythropoiesis. The comparison of sTfR as a diagnostic marker showed it to be a better indicator than the traditional markers, such as ferritin, under inflammatory conditions. Conclusion: IV iron supplementation is better than oral iron for treating severe iron deficiency in patients with CKD, leading to better clinical outcomes. New biomarkers, such as sTfR, are much better in evaluating iron status in CKD patients than before, especially in those with concurrent inflammation. All these weighs heavily toward individualized management of the disease.