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

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.

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.

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).

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.