The Impact of NAFLD on Hospitalization Outcomes in Patients With Inflammatory Bowel Diseases: Nationwide Analysis

Abstract

Nonalcoholic fatty liver disease (NAFLD) is highly prevalent in patients with inflammatory bowel diseases (IBD). Yet, the impact of NAFLD on outcomes, along with the contribution of nonmetabolic factors to NAFLD development, is unclear. To investigate these topics, we conducted a nationwide study examining the impact of NAFLD on hospitalization outcomes in IBD patients after adjusting for metabolic factors. Patients with IBD-related hospitalizations were identified using the Nationwide Readmissions Database from 2016 to 2018. Inflammatory bowel disease patients with and without NAFLD were matched based on IBD type, age, sex, metabolic syndrome, and diabetes mellitus. Primary outcomes were IBD-related readmission, IBD-related surgery, and death. Secondary outcomes were length of stay (LOS) and cost of care (COC). The primary multivariable model adjusted for obesity, dyslipidemia, Charlson-Deyo comorbidity index, hospital characteristics, payer, patient income, and elective status of admissions. Nonalcoholic fatty liver disease was associated with a higher risk of IBD-related readmission (adjusted hazard ratio, 1.90; P < .01) and death (adjusted hazard ratio, 2.73; P < .01), 0.71-day longer LOS (P < .01), and $7312 higher COC (P < .01) in those with Crohn's disease. Nonalcoholic fatty liver disease was also associated with a higher risk of IBD-related readmission (adjusted hazard ratio, 1.65; P < .01), 0.64-day longer LOS (P < .01), and $9392 (P < .01) higher COC, but there was no difference in death in those with UC. No differences in risk of IBD-related surgery were observed. Nonalcoholic fatty liver disease is associated with worse hospitalization outcomes in IBD patients after adjusting for metabolic factors. These data suggest nonmetabolic factors may be implicated in the pathogenesis of NAFLD in IBD patients and may contribute to worsened clinical outcomes.