Gender-specific effects of appendectomy on inflammatory bowel disease: Increased odds of Crohn's disease, and decreased odds of ulcerative colitis in women-An analysis using the National Inpatient Sample.

This study investigates the gender-specific and demographic associations of appendectomy on the concurrent diagnosis of inflammatory bowel disease (IBD), using data from the National Inpatient Sample (2018-2021), comprising 25,950,053 hospitalized patients. Among the cohort, there were a total of 1,207,569 patients who underwent an appendectomy during the hospitalization. Similarly, there were 648,751 and 338,357 patients with a diagnosis of ulcerative colitis (UC) and Crohn's disease (CD), respectively. Multivariate logistic regression models were employed to assess the association between appendectomy and IBD diagnoses, adjusting for age, gender, race, income, and hospital division. Patients who underwent an appendectomy during hospitalization had a 68% lower odds of concurrent UC diagnosis compared to those without an appendectomy (odds ratio (OR) 0.32; 95% confidence interval (CI) 0.18-0.58; p < 0.001). Female patients showed a 10% lower odds of UC diagnosis compared to male patients (OR 0.90; 95% CI 0.87-0.93; p < 0.001). However, the interaction between appendectomy and gender was not statistically significant (OR 1.15; 95% CI 0.50-2.65; p = 0.746). For CD, patients undergoing an appendectomy during hospitalization had increased odds of CD diagnosis compared to those without an appendectomy (OR 1.42; 95% CI 1.12-1.80; p = 0.003). Female patients showed a significantly higher odds of CD diagnosis compared to males (OR 1.42; 95% CI 1.12-1.80; p = 0.003). Regional disparities and racial differences in IBD diagnosis were also observed. These findings suggest that patients with UC and CD have differential risks of appendectomy and may influence the development of UC and CD, with gender-specific variations. Further studies are needed to explore the underlying mechanisms.