P0452A high Body Mass Index at baseline is not associated with certain poor IBD-related outcomes

Background The paradigm of inflammatory bowel disease (IBD) is shifting from an undernourished state to one where obesity is a prevalent comorbidity1. Recent data from a large-scale Australasian cohort (7134 people with IBD) documented in the binational Crohn’s Colitis Care (CCCare) registry showed that 23.2% were obese and 32% overweight; with a statistically significant increase in cardiometabolic comorbidities as the BMI progressed from healthy to obese ranges2. Here, we aimed to assess for potential associations of baseline BMI on IBD outcomes. Methods Using the CCCare registry, we conducted a real-world multicentre cohort study of adults with IBD and at least 12 months follow up period; aiming to assess the association of baseline BMI (first recorded in CCCare) on IBD outcomes. De-identified data including BMI were extracted. The primary outcome was the composite of any of the following, at any time after baseline: new steroid use, new admission for IBD or IBD-related surgery. Logistic regression models that included nonlinear terms for continuous BMI were used. Results A total of 3230 individuals were included in the study. Of whom, 52% were male, 61% had Crohn’s disease and 20% had reported steroid use at baseline. Median BMI at baseline was 25.5 Kg/m2(interquartile range 22.3, 29.3). 84 patients with a BMI over 50 were excluded from the analyses due to low precision in the estimated effects in this range. The median duration of follow up period was 31 months (23, 34). Adjusting for prespecified covariates including age at first assessment, gender, diagnosis at baseline, steroid use at first assessment and use of advanced therapies at first assessment, we found that BMI at first assessment was significantly associated with the primary composite outcome (p = 0.009) (Figure1). The highest risk of outcome was for lowest BMI < 15, and was relatively stable for BMI > 22. BMI was not associated with clinical or endoscopic remission at any follow up after baseline. Conclusion In this cohort, the composite outcome of steroids uses, IBD-related admissions or surgery; was associated with an underweight rather than an obese phenotype. The use of BMI rather than waist circumference, the duration of follow up, excluding patients with a BMI=‘, serif;” > ≥ 50 & the size of the cohort could have affected our results. Future work with larger cohorts measuring the visceral adiposity or using the waist circumference as a surrogate marker of the visceral adiposity are needed. References: 1. Kaazan P, Seow W, Yong S, Heilbronn LK, Segal JP. The Impact of Obesity on Inflammatory Bowel Disease. Biomedicines. 2023 Dec 8;11(12):3256. doi: 10.3390/biomedicines11123256. PMID: 38137477; PMCID: PMC10740941 2. Kaazan P, Seow W, Wilson B, Connor S, Andrews JM. The Trend of Obesity and IBD in Australia and New Zealand: A bi-nation cohort study. In Submission Conflict of interest: Dr. Kaazan, Patricia: Speaker fee and education support from: Falk Pharma, Pfizer, Abbvie, Takeda, arrotex and Sandoz. Caquilpan, Victor: No conflict of interest Connor, Susan: Susan J Connor has received honoraria for Advisory Board participation, speaker fees, educational support and/or research support from: Abbvie, Agency for Clinical Innovation, Amgen, BMS, Chiesi, Celltrion, Cornerstones Health, DrFalk, Eli Lilly, Ferring, GSK, Janssen, Medical Research Future Fund, Organon, Pfizer, Sandoz, South Western Sydney Local Health District, Sydney IBD School, Sydney Partnership for Health, Research and Enterprise, Takeda and The Leona M and Harry B Helmsley Charitable Trust Andrews, Jane Mary: Grant: The work I will present was funded via CCCure. CCCure’s funding sources include grants for research and payments for data reports from Pharma including AbbVie,J & J, Takeda, Celltrion, Falk, Ferring, BMS, Janssen, Pfizer, Sandoz