Effectiveness And Safety Between Intravenous Versus Oral Iron For The Treatment Of Iron Deficiency Anemia In Inflammatory Bowel Disease:a Meta-Analysis

Objective To systematically review the differences in effectiveness and safety between intravenous (IV) versus oral (PO) iron replacement in adult inflammatory bowel disease (IBD) with iron deficiency anemia (IDA).Methods Databases including The Cochrane Library, PubMed, MEDLINE, Embase, WanFang, CNKI and VIP Data were electronically searched for randomized controlled trials (RCTs) about IV versus PO iron replacement in adult IBD with IDA from inception to December 2015. We also hand-searched related conference proceedings and references of included studies for additional studies. Two reviewers independently screened literature, extracted data and assessed the methodological quality of trails according to the Cochrane Reviewer’ s Handbook 5.1 for systematic reviews of interventions. Then, meta-analysis was performed by using Stata 12.0 software. For the effectiveness-relevant measures, The primary outcome was the effect of treatment for anemia in IBD on the hemoglobin (HB) response, defined as rate of patients who achieved an increase of 2 g/dL in HB concentration at the end of the follow-up. Secondary outcomes included the mean change in HB and mean change in serum ferritin (SF). The safety-relevant measures included CRP levels the adverse reaction rate.Results A total of 6 RCTs involving g 780 patients were included. The results of meta-analysis showed that for the primary outcome of "response" (HB rise>2 g/dL), IV iron was associated with a higher rate of achieving HB response in comparison to oral iron (RR:1.156,95%CI:1.02-1.31, P<0.05). For the secondary outcome, IV iron was associated with a significantly greater initial rise in SF compared with PO iron (WMD:96.46 ng/mL; 95%CI,90.40-102.88, P<0.05). But the mean change in HB between PO and IV iron was not statistically significant (WMD:0.49 g/dL,95%CI:-0.07-1.06, P>0.05). There was a lower risk of withdrawal due to adverse events in these trials in the IV iron cohorts when compared with PO iron (RR:0.40,95%CI:0.20-0.81; P=0.004). The CRP levels between PO and IV iron was not statistically significant (WMD:0.99,95%CI:-1.40-3.39, P>0.05).Conclusion IV iron appears to be more effective and safey than oral iron for the treatment of IBD-associated IDA by improving HB response and lower risk of withdrawal due to adverse events. Due to the limited quality and quantity of the included studies, the above conclusion needs to be further verified by more high quality studies.