Iron Replacement in Patients with Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

Background:A number of controlled trials and prospective studies have compared intravenous (IV) to oral (PO) iron for the treatment of iron deficiency anemia with mixed results.Methods:We conducted a systematic review of trials published on 2014 that compared IV with PO iron to treat in patients with IBD. Meta-analysis was performed to generate effect estimates. Quality assessment was also performed according to GRADE criteria.Results:Five studies met our inclusion criteria, enrolling 694 patients. For the primary outcome of response (hemoglobin rise >2 g/dL), there was no significant difference between IV or PO iron; risk ratio for response with IV was 1.08 (95% CI, 0.9-1.2; P = 0.2). For the secondary outcome of mean change in hemoglobin (g/dL), the mean difference between PO and IV iron was not statistically significant (mean difference, 0.6 g/dL, 96% CI, -0.1 to 1.3; P = 0.08). IV iron was associated with a significantly greater initial rise in serum ferritin compared with PO iron (mean difference 89 ng/mL; 95% CI, 29-148, P = 0.003). There was a lower risk of withdrawal due to adverse events in these trials in the IV iron cohorts when compared with PO iron (risk ratio, 0.4; 95% CI, 0.1-1.0; P = 0.05).Conclusions:We found no significant difference between IV and PO iron in correcting iron-deficiency anemia in patients with IBD in this meta-analysis. Patients who received IV iron had a greater rise in serum ferritin and were less likely to stop treatment due to adverse events, when compared with those who received PO iron.