Maximizing iron uptake in inflammatory bowel disease: An updated systematic review and meta-analysis of intravenous vs oral iron therapy

Abstract

Background and Aims: Anemia is the most common extraintestinal complication of inflammatory bowel diseases (IBD). Iron deficiency anemia (IDA) can be treated with oral or intravenous (IV) iron supplementation. The aim of this study is to compare the efficacy and tolerability of oral and IV iron supplementation for treating anemia in adult IBD patients. Methods: A systematic review and meta-analysis of randomized controlled trials were conducted. Databases including PubMed, Web of Science, Scopus, and Cochrane Central Register of Controlled Trials were searched until December 2022. Trials that included individuals with IBD and compared IV to oral iron for treating IDA were eligible. Two reviewers independently extracted data, and another two reviewers independently graded each trial's risk of bias. The fixed-effect model was used to obtain pooled odds ratio (OR) estimates and their 95% confidence intervals (CI). Results: Five trials, including 910 IBD patients, were eligible for analysis. The meta-analysis showed that IV iron was more effective than oral iron for raising hemoglobin levels to 2.0 g/dL (OR: 1.44, 95% CI: 1.09 - 1.91, P = 0.01). The IV iron groups had decreased rates of treatment withdrawal prompted by adverse side effects or intolerance (OR: 0.26, 95% CI: 0.13 - 0.51, P < 0.0001). There was no evidence of heterogeneity across all studies. Conclusion: IV iron appears to be more efficient and well-tolerated than oral iron for treating anemia associated with IBD. The findings suggest that IV iron may be a preferred treatment option for IBD patients with IDA.