Gender-Affirming Hormone Therapy and Risk of IBD Flare in Transgender and Gender Diverse Adults.

OBJECTIVES Little is known about the impact of gender-affirming hormone therapy (GAHT) on transgender and gender diverse adults with inflammatory bowel disease (IBD). The primary aim was to evaluate the incidence of IBD flare in the year before and after GAHT initiation. METHODS A retrospective study across five IBD centers. Flare was defined as need for steroids, IBD-associated emergency department visit, or need for IBD medication change. Factors associated with IBD flare were assessed with univariate analysis and multivariable logistic regression controlling for age and IBD type. RESULTS 85 transgender and gender diverse adults with IBD who initiated GAHT were included in this study. 46 (54.1%) received estrogen and 39 (45.9%) received testosterone. In the year prior to GAHT, 42 (49%) flared compared to 32 (38%) in the year after, p=0.06. There was no statistically significant difference in incidence of flare by age, IBD type, or IBD therapy type. Individuals with active IBD at GAHT initiation were more likely to flare in univariate (58% vs 24%, p=0.003) and multivariable analysis (aOR 5.1 [95% CI 1.7 - 15.2]). In both univariate and multivariable analysis, individuals who received testosterone were more likely to flare in the year after starting GAHT, testosterone: 51% vs estrogen: 26%, p=0.02 with an aOR 3.1 [95% CI 1.2 - 8.1]. CONCLUSIONS While there was no overall increased risk of flare in the year after GAHT start, those with active IBD prior to hormone start and those who received testosterone were more likely to experience an IBD flare.