Supplementary Material for: Comparison of two oral iron formulations for iron deficiency and iron deficiency anemia in Inflammatory Bowel Disease: a prospective study

Introduction: The use of oral iron in iron deficiency (ID) and ID anemia (IDA) in inflammatory bowel disease (IBD) is controversial. Its lower cost and ease of administration must be weighed against side effects and efficacy. The aim of this study was to compare the efficacy and tolerability of two oral iron formulations (Sucrosomial® iron (SI) and ferric hydroxide-polymaltose complex (FHPC) for correcting ID and IDA in IBD. As a secondary objective, we aimed to assess the impact of oral iron on correcting ID, IDA, and disability in IBD.
Methods: This was a prospective, observational, bicentric cohort study. We included patients with IBD diagnosed with ID or IDA between November 2022 and November 2023. Physicians were pre-assigned by the investigators to prescribe SI or FHPC. The primary outcome was the efficacy of treatment with oral iron (Hb increase ≥2 g/dL and/or normalization of Hb levels in patients with IDA or correction of iron parameters in patients with ID alone) by week 12. The secondary outcomes were tolerability and the impact of oral iron on the quality of life and disability (IBD-Disk).
Results: Fifty-six patients were included in this study (FHPC group, 33; SI group, 23). A total of 47 patients had ID alone and 9 had IDA. There was no difference in the efficacy between the two formulations. After 12 weeks, 22% of the patients had an increase in Hb ≥ 2 g/dL and/or normalization of Hb levels or iron parameters. There was an improvement in serum iron (53.5 [45] vs. 64.5 [73]; p=0.017), transferrin saturation index (17.0 [10] vs. 26.0 [13]; p<0.001), and Hb levels (in patients with IDA) (11.9 ± 0.9 versus 12.5 ± 1.2; p=0.041). The IBD-disk scores improved (p=0.004) after treatment, and this improvement correlated with increased serum iron (rs=-0.43; p=0.010) and Hb (rs=-0.50; p=0.002) levels. Twelve (21.4%) patients had side effects (8.7% in the SI group vs. 30.3% in the FHPC group (p=0.006)), leading to iron discontinuation in 5 (4/1: FHPC group/SI group).
Discussion: Both iron formulations had similar efficacy. There were fewer side effects in the SI group. Oral iron replacement improved Hb and iron levels after 12 weeks of treatment, and these changes correlated with improvement in disability.