The association between bilirubin concentrations and inflammatory bowel disease: Insights from a systematic review and meta-analysis

Background: Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), poses a significant challenge to health care systems because of its chronic nature and increasing global prevalence. Effective management of IBD requires accurate diagnostic tools and biomarkers. This systematic review and meta-analysis aimed to evaluate the relationship between bilirubin concentrations and IBD activity and outcomes. 

Methods: A comprehensive search of electronic databases identified 11 studies that included 2606 subjects with IBD and 3607 healthy controls. 

Results: Bilirubin concentrations were significantly lower in subjects with IBD when compared to controls (SMD = −0.96, 95% CI −1.21 to −0.70; p <.001). Although substantial heterogeneity was observed, sensitivity analysis confirmed the robustness of the results. Publication bias was detected, but subgroup analyses did not significantly alter the results. Meta-regression showed that age was a significant factor influencing the association between bilirubin concentrations and IBD. Subgroup analyses showed a more pronounced reduction in bilirubin concentrations in subjects with CD than those with UC. 

Conclusion: This study supports the potential utility of bilirubin as a biomarker in IBD, emphasizing the need for further research to validate its clinical significance.