Risk factors of inflammatory bowel disease complicating anemia: A systematic review and meta-analysis.

BACKGROUND: Inflammatory bowel disease (IBD) frequently complicates with anemia, which worsens disease prognosis and quality of life. However, the risk factors for IBD complicating anemia remain unclear. This study aims to systematically evaluate the risk factors of anemia in patients with IBD, and provide evidence for clinical practice. METHODS: We systematically searched PubMed, Web of Science, Embase, Cochrane Library, CNKI, Wanfang Data, Cqvip, and SinoMed databases up to December 1, 2024. Literature screening, data extraction, and quality assessment were independently performed by 2 reviewers. Meta-analysis was conducted using Review Manager (RevMan) version 5.3. RESULTS: Fourteen studies, involving 111,940 patients, were included. Six significant risk factors were identified: advanced age (odds ratio [OR] = 1.07), smoking history (OR = 1.88), active disease (OR = 2.11), elevated C-reactive protein levels (ulcerative colitis: OR = 2.20; Crohn disease: OR = 2.06), decreased albumin levels (ulcerative colitis: OR = 0.78; Crohn disease: OR = 0.88), and penetrating disease behavior (B3) (OR = 6.08). CONCLUSION: Multiple factors are associated with an increased risk of anemia in patients with inflammatory bowel disease. The early identification of these factors may facilitate timely risk stratification, closer monitoring, and targeted interventions.