Chronic kidney disease in inflammatory bowel disease, a systematic review and meta-analysis.

Inflammatory bowel disease (IBD) is associated with various immune mediated disorders including spondylarthritis, pyoderma gangrenosum, primary sclerosing cholangitis and uveitis. Chronic kidney disease (CKD) is defined by a reduction in kidney function (eGFR less than 60ml/min/1.73m2) and/ or damage markers that are present for at least three months, regardless of the aetiology. Case reports and cohort studies suggest that IBD is associated with CKD. The extent and magnitude of a potential association is unknown. A comprehensive search was conducted in EMBASE, MEDLINE, Web of Science, the Cochrane database, and SCOPUS. Two separate reviewers were involved in the process of article selection and evaluation. Odds ratios were calculated in those papers with a comparison between an IBD population and a non-IBD control population, the Mantel Haenszel test was employed, utilizing a random effect model. The systematic review was registered in PROSPERO (RD42023381927). Fifty-four articles were included in the systematic review. Of these, eight articles included data on prevalence of CKD in IBD patients (n = 102,230) vs. healthy populations (n = 762,430). Of these, diagnosis of CKD was based on ICD codes in five studies vs. on eGFR in three studies. The overall odds ratio of developing CKD in the IBD population is 1.59 (95%CI 1.31-1.93), without any difference between studies using diagnostic coding (OR 1.70 95%CI 1.33-2.19) vs. diagnosis based on eGFR (OR 1.36 95%CI 1.33-1.64). IBD is associated with a clinically meaningful increased CKD prevalence. We provide recommendations on diagnostic evaluation, as well as suggestions for future research.