Acute Pancreatitis in Ulcerative Colitis: Nationwide Prevalence, Etiologies, and Hepatobiliary Risk Factors

Abstract BACKGROUND Acute pancreatitis (AP) is a recognized complication of inflammatory bowel disease (IBD), yet most epidemiologic evidence has focused on Crohn’s disease. Data regarding the burden, etiologic spectrum, and risk profile of AP in ulcerative colitis (UC) are limited. We sought to define the prevalence, causes, and hospitalization-associated factors for AP in a large, nationally representative UC cohort. METHODS We conducted a retrospective cross-sectional study using the 2016–2020 Nationwide Readmission Database. Adult index hospitalizations for ulcerative colitis (UC) were identified by ICD-10-CM codes, and acute pancreatitis (AP) was defined by a concurrent admission code. Demographic, comorbidity, and etiologic profiles were compared between patients with and without AP, and multivariable logistic regression was used to identify independent predictors of AP. RESULTS Among 205,107 UC hospitalizations, 3,125 (1.5%) had a concurrent diagnosis of AP. Compared with those without AP, patients with AP were younger (median age, 50 vs. 57 years; P 0.001), and more often male (51.4% vs. 45.5%; P 0.001). Patients with AP were younger (median age, 50 vs. 57 years; P 0.001), with a higher proportion aged 18–44 years (41.0% vs. 29.3%; P 0.001), and more often male (51.4% vs. 45.5%; P 0.001). Metabolic and hepatobiliary comorbidities were more frequent in the AP group, including Metabolic dysfunction–associated steatotic liver disease (MASLD) (6.4% vs. 1.8%; P 0.001), gallstone disease (3.8% vs. 1.1%; P 0.001), and obesity (13.0% vs. 11.4%; P = 0.006). Among AP cases, the most common identified etiologies were biliary (17%), alcohol-induced (16%), and drug-induced (10%). In multivariable analysis, gallstone disease (OR, 3.61; 95% CI, 2.98–4.37; P 0.001) and MASLD (OR, 3.06; 95% CI, 2.63–3.56; P 0.001) were the strongest independent predictors of AP. Additional associations included hepatic failure (OR, 1.75; 95% CI, 1.41–2.19; P = 0.014), hypokalemia (OR, 1.34; 95% CI, 1.23–1.46; P 0.001), thrombocytopenia (OR, 1.36; 95% CI, 1.17–1.57; P 0.001), hypertension (OR, 1.19; 95% CI, 1.09–1.29; P 0.001), and diabetes mellitus (OR, 1.12; 95% CI, 1.02–1.23; P = 0.017). Younger age was independently associated with greater odds of AP, with progressively lower risk in the 45–64 years (OR, 0.74; 95% CI, 0.68–0.81; P 0.001) and ≥65 years (OR, 0.36; 95% CI, 0.33–0.40; P 0.001) groups. CONCLUSIONS In this large, nationwide UC cohort, AP occurred in approximately 1 in 65 hospitalizations and was independently associated with younger age, male sex, and hepatobiliary comorbidities, particularly gallstone disease, MASLD, and hepatic failure. These findings highlight the need for early recognition and management of modifiable hepatobiliary risk factors to reduce AP burden and improve outcomes in hospitalized UC patients.