S1566 Impact of Obesity on Recurrence and Treatment Escalation in Pouchitis After IPAA in Patients With Ulcerative Colitis

Introduction: Acute pouchitis is the most common complication after ileal pouch–anal anastomosis (IPAA) in ulcerative colitis (UC), affecting up to 50% of patients. About 10%–15% progress to chronic antibiotic-dependent or -refractory pouchitis. Obesity has been associated with increased risk of pouch inflammation, but its impact on recurrence and treatment escalation remains unclear. Methods: We conducted a retrospective cohort study using the TriNetX database to assess whether obesity influences outcomes in patients with UC-IPAA and a history of pouchitis. Patients were categorized by BMI into obese and non-obese cohorts. Non-obese cohort included body mass index (BMI) between 18.5 and 24.9 kg/m². The primary outcome was a composite of repeat antibiotic use or advanced therapy (AT) initiation at 1 and 2 years. Secondary outcomes included pouch excision, mesalamine and oral or topical steroid use. Subgroup analyses were conducted for BMI 30–39 and ≥40 kg/m². Adjusted odds ratios (aORs) were calculated after 1:1 propensity score matching. Results: We identified 449 patients with obesity (mean age 44.4 ± 14.3 years; 53.9% male; 75.7% White) and 712 without obesity (mean age 35.2 ± 15.1 years; 53.3% male; 81.7% White). Within 1 and 2 years of the index pouchitis episode, there was no significant difference in the composite primary outcome between patients with and without obesity (1-year: 56.6% vs 51.2%; aOR 1.24, 95% CI 0.92–1.66, P = 0.15; 2-year: 64.2% vs 58.8%; aOR 1.25, 95% CI 0.92–1.69, P = 0.14). Similarly, the risk of recurrent pouchitis did not differ significantly at either timepoint. However, patients with obesity had higher AT use at both 1 year (10.7% vs 4.7%; aOR 2.38, 95% CI 1.31–4.30; P = 0.003) and 2 years (14.1% vs 7.6%; aOR 1.99, 95% CI 1.21–3.26; P = 0.005), as well as increased steroid use at 1 year (26.1% vs 19.7%; aOR 1.44, 95% CI 1.01–2.05; P = 0.04) and 2 years (30.7% vs 23.9%; aOR 1.40, 95% CI 1.01–1.96; P = 0.04). In subgroup analysis, patients with BMI 30–39 had significantly greater AT use compared to patients without obesity (15.4% vs 8.4%; aOR 1.98, 95% CI 1.23–3.18; P = 0.003). At 2 years, Crohn’s-like disease of pouch occurred in 11.1% of patients with obesity vs 10.7% without obesity (P = 0.83). Conclusion: Obesity was associated with an increased risk for AT initiation but not repeat antibiotic use in patients with UC-IPAA and obesity with a history of pouchitis.