Abstract
Background and Aims
Iron deficiency anemia occurs in the vast majority of patients with chronic kidney disease (CKD). The aim of this study was to investigate the efficacy of ferric carboxymaltose (FCM) iron deficiency anemia’s treatment in non-dialysis CKD patients and to clarify its impact on kidney function.
Method
Prospective observational study of non-dialysis CKD stage 3 to 5 patients, with anemia and iron deficiency treated with FCM from 01 January 2019 to 31 June 2020. FCM was administrated as a single IV infusion of 500mg or 1000mg. Baseline clinical, analytical and demographic data were recorded. FCM efficacy was evaluated by comparing hemoglobin (Hb), serum ferritin and transferrin saturation index (TSAT) 24 ± 8 weeks after the infusion with analytical values at baseline. Renal function was also assessed at baseline and at 24 ± 8 weeks using estimated glomerular filtration rate (eGFR), calculated by CKD-EPI formula. Statistical analysis was executed using SPSS (Version 23 for Mac OSX).
Results
The average age of 71 patients was 77.31 ± 9.68 years, 29 (40.8%) were male, 46 (64.8%) were diabetic and 41 (57.8%) had congestive heart failure. Sixteen (22.5%) patients had CKD stage 3, 41 (57.7%) stage 4 and 14 (19.7%) stage 5. Twenty-five (35.2%) patients were treated with 1000mg of FCM. At baseline, average hemoglobin level (Hb) was 10.16 ± 1.12g/dL, serum ferritin 83.25 ± 96.55µg/L, TSAT 14.48 ± 6.72mg/dL and eGFR 24.21± 13.09ml/min/1.73m2. At 24 ± 8 weeks, Hb showed an increase of 1.31 ± 1.49 g/dL (p=0.001) and TSAT 10.68 ± 10.40% (p=0.001). Serum ferritin showed also an increase of 4.75 ± 180.53µg/L but did not reach statistical significance. The increase in Hb was observed uniformly across all stages of CKD. A Pearson correlation revealed a positive correlation between the variation of Hb and eGFR during the study follow-up period (r=0.310, p=0.008). A subgroup analysis was performed, patients were classified in 2 groups according to FCM dose. At baseline, there was no age, comorbidities or eGFR difference among groups. Patients treated with 1000mg had lower Hb (p=0.03) and serum ferritin (p=0.01). At 24±8 weeks both groups showed increases in Hb (p=0.001) and TSAT (p=0.001). Patients treated with 1000mg showed also a significant increase in ferritin (p=0.004). The Pearson correlation confirmed a positive correlation between the variation of Hb and eGFR in the group of patients treated with 1000mg (r=0.467, p=0.019) but not in the group treated with 500mg.
Conclusion
FCM was effective in the treatment of iron deficiency anemia in non-dialysis CKD stage 3 to 5 patients. In our population, the increase of Hb levels correlated with an improvement in eGFR in patients treated with higher doses of FCM, suggesting a positive impact of FCM on kidney function.
Oral versus intravenous iron therapy in iron deficiency anemia: An observational study