Exploring the Link Between Inflammatory Bowel Disease and Chronic Kidney Disease: A Nationwide Database Study

<b>Background/Objectives</b>: Inflammatory bowel disease (IBD) has widely been associated with various extraintestinal complications, including kidney disease. The literature suggests that IBD patients are at increased risk of developing chronic kidney disease (CKD). This study aims to assess the relationship between IBD and CKD, and to identify risk factors associated with CKD in patients with IBD. <b>Methods</b>: Data for hospitalized patients with IBD was obtained from The National Inpatient Sample (NIS) database from 2016 to 2020. Baseline risk factors were identified using ICD-10 codes. Patients were stratified into two groups: Crohn's Disease (CD) and Ulcerative Colitis (UC). Primary outcomes were prevalence and risk factors of CKD. Secondary outcomes were mortality and length of hospital stay (LOS). Univariate and multivariate analyses were conducted using SPSS v. 30. <b>Results</b>: We identified 230,766 patients with IBD: 144,847 (63%) had CD and 85,919 (37%) had UC. After 1:1 matching, 148,498 patients were included: 74,249 with CD and 74,249 with UC. In this study group, the prevalence of CKD in patients with CD and patients with UC was the same (7.2%). CD patients with CKD had lower in-hospital mortality rates and lower in-hospital length of stay compared to UC patients with CKD. <b>Conclusions</b>: While the prevalence of CKD is similar amongst CD and UC patients, the risk factors and outcomes such as mortality and length of hospitalization differ significantly. This study emphasizes the need for tailored approaches and closer monitoring for the risk of developing CKD in IBD patients and especially patients with UC.