Effect of iv ferric carboxymaltose on physical performance and qol in patients with ckd not on dialysis, mild anemia and iron deficiency

Abstract Background and Aims Iron deficiency (ID) in patients with chronic kidney disease (CKD) is highly prevalent and contributes to a poorer quality of life. According to current guidelines, treatment with intravenous (IV) iron is limited to CKD patients with ID and anemia to avoid/delay the use of erythropoiesis-stimulating agents (ESAs) or the reduce the doses of ESA in patients treated with these drugs. Considering the effects of the correction of ID in other settings, we hypothetized that treatment with IV iron in patients with ID and borderline anemia can improve physical performance and their quality of life, independent of the effects on hemoglobin. Method Prospective, unicentric, single-arm study in CKD patients with ID, mild anemia and with-out heart failure. The inclusion criteria were: age ≥ 18 years, CKD patients stages 3–5 not on dialysis, iron deficiency (ferritin <100 ng/ml or ferritin <200 ng/ml if TSAT <20%), mild anaemia (Hb 10.5-11.5 g/dL). At the baseline visit, after all the studies were performed, iv ferric carboxymaltose was administered in a single dose, according to the degree of ID calculated by the Ganzoni´s formula. The co-primary outcome was the change in physical performance, evaluated through the 6 minute-walk test (6MWT) at one week and at four weeks. Secondary end-points: Patient's global assessment (PGA) and quality of life (EQ-5D), Piper's fatigue test, serum phosphorous at four week. Laboratory data, PGA, EQ-5D and Piper test questionnaires were evaluated at baseline, and at weeks 1 and 4 after receiving IV ferric carboximaltose. Results 41 patients completed the study. Primary end-point: the 6MWT increased significantly from 296 ± 101 m to 314 ± 106 m at week 1 (p<0.01), and to 325 ±111 meters at week 4 (p<0.01). at week 4 (p = 0.083). A significant improvement in the PGA test values was detected when compared baseline vs 4 weeks (adjusted p value = 0.031). No significant differences were found between the baseline and week 1 (adjusted p value = 0.083), and week 1 and week 4 visits (adjusted p value = 0.086). No significant differences were found between the initial, 1-week, and 4-week visits in the EQ-5D quality of life questionnaire nor Piper's fatigue test. Phosphorus levels decreased significantly at week 1 from baseline (3.16 ± 0.7 vs 3.72 ± 0.6) (adjusted p<0.001), with a partial recovery of serum levels in week 4 (3.57 ± 0.7 mg/dL). There were no significant increases in hemoglobin concentration between the different time periods. Conclusion IV ferric carboximaltose administration significantly improved the functional capacity of CKD patients with ID in short term. PGA also improved slightly but significantly. Effects that were independent of hemoglobin changes, suggesting a role of ID for a lower physical performance in CKD patients without heart failure, independent of the presence of anemia.