S1698 Unraveling the Obesity Paradox in Inflammatory Bowel Disease: A Retrospective Cohort Study

Introduction: The “obesity paradox” suggests that, despite a higher baseline risk for adverse health outcomes, obese patients can experience lower complication and mortality rates in chronic conditions such as inflammatory bowel disease (IBD). This study aims to examine the association between obesity and inpatient outcomes of IBD patients. Methods: We conducted a retrospective cohort study using the multi-institutional TriNetX research network to evaluate the risk of adverse outcomes in patients with IBD based on body mass index (BMI). These patients were divided 3 cohorts based on BMI: normal BMI cohort (<25 kg/m2), overweight cohort (≥25.0 to 29.9 kg/m2) and obese cohort (>30.0 kg/m2). Underweight (<18 kg/m2), patients were excluded from the analysis. One-to-one propensity score matching was performed based on demographics and IBD specific medications. Outcomes were reported as adjusted odds ratios (aOR) with 95% confidence intervals (CI). Results: A total of 665,254 patients with IBD were included in the study, out of which 174,233 had normal weight, 152,830 were overweight and 159,864 were obese. When comparing the overweight cohort to the normal weight cohort, there was decreased odds of mortality (aOR 0.60, P < 0.01), all cause hospitalization (aOR 0.86, P < 0.01) and IBD specific hospitalization (aOR 0.94, P < 0.01). In subgroup analysis by IBD subtypes, Crohn’s disease (CD) had similar decrease in mortality, all cause hospitalization and CD specific hospitalization. In contrast, ulcerative colitis (UC) had no difference in UC specific hospitalization (aOR 1.01, P = 0.61) but decrease in mortality and all cause hospitalization. When comparing the obese cohort to the normal weight cohort, there was decrease in all-cause mortality (aOR 0.66, P < 0.01), but increased odds of all cause (aOR 1.09, P < 0.01) and IBD specific hospitalization (aOR 1.15, P < 0.01). On comparing the IBD subtypes both UC and CD had similar decrease in mortality but increased odds of all cause and disease specific hospitalization. Conclusion: Our results show that an obesity paradox may exist in IBD in terms of mortality, but is not consistent across all outcomes. The paradox is more apparent in overweight patients than those with obesity. Future research examining a broader spectrum of outcomes is warranted to more accurately characterize the role of obesity in IBD prognosis.