Acute Kidney Injury in Inflammatory Bowel Disease Patients: A Nationwide Comparative Analysis

Rationale & Objective About 25-40% of patients with inflammatory bowel diseases (IBD) may have extra-intestinal manifestations, mainly involving the liver, skin, and joints. Kidney involvement in patients with IBD has been reported, but there are no estimates of its prevalence in population-based studies in the US. We compared the frequency of AKI among hospitalizations with IBD to hospitalizations with collagen vascular diseases and hospitalizations without IBD or collagen vascular diseases. Study Design Retrospective, population-based cohort study Setting and Participants Healthcare Cost and Utilization Project (HCUP)--Nationwide Inpatient Sample (NIS) database. Exposure TK Outcomes Acute kidney injury (AKI) and AKI requiring dialysis. Analytical Approach Regression models were used to compare occurrence of AKI among groups. Inverse probability of treatment weighting (IPTW) applied to balance groups on covariates. Results The final sample comprised of 5,735,804 hospitalizations, including 57,121 with IBD, 159,930 with collagen vascular diseases and 5,518,753 without IBD or collagen vascular diseases. AKI was observed in 13%, 15%, and 12.2% of hospitalizations with IBD, collagen vascular diseases, and the general population, respectively. When adjusting for demographic, hospital, and clinical characteristics using IPTW, hospitalizations with IBD had higher odds of being diagnosed with AKI compared to both the collagen vascular diseases (OR, 1.32; 95% CI, 1.27-1.38) and general population (OR 1.27, 95% CI, 1.23-1.31), and also had higher odds of being diagnosed with AKI requiring dialysis compared to collagen vascular diseases (OR, 1.59; 95% CI 1.31, 1.94) and general population (OR,1.45; 95% CI 1.25, 1.68). Limitations Cross-sectional analysis, underreporting of ICD codes, and analyses relevant to in-hospital stays only. Conclusions The prevalence and risk of AKI among hospitalization with IBD is greater than that of the hospitalization in the collagen vascular diseases and the general population cohort. Coexisting kidney disease should be considered among patients with a known diagnosis of IBD.