S2024 The Impact of Concomitant Hypothyroid Disease and Inflammatory Bowel Disease in Older Adults: Underrecognized and Underappreciated

Introduction: Inflammatory bowel disease (IBD) is a chronic immune-mediated disorder often complicated by extraintestinal manifestations (EIMs). Hypothyroidism (HT), particularly autoimmune thyroiditis, shares overlapping immunopathogenic pathways with IBD, including dysregulated T-cell activation and cytokine signaling. Although HT is linked to systemic autoimmune diseases, its impact on IBD outcomes in older adults remains unclear. We aimed to evaluate factors associated with HT in older adults with IBD and its effect on laboratory and healthcare utilization outcomes. Methods: We conducted a retrospective study at a large academic center among adults aged ≥60 years with IBD and ≥1 thyroid-stimulating hormone (TSH) measurement prior to January 1, 2022. Patients were stratified by HT status. Demographics, clinical characteristics, medication history, labs, and healthcare utilization were collected. Associations were assessed using Chi-Squared, Fisher’s Exact, or Wilcoxon Rank-Sum tests. Multivariable logistic regression evaluated factors associated with HT, while logistic and negative binomial regression assessed HT as a predictor of anemia and healthcare utilization (2016–2022). Results: Among 158 older adults with IBD (median age 75.4 years, 63.3% women), 119 (75.3%) had HT. Demographics, smoking status, BMI, and IBD subtype were similar by HT status. Extraintestinal manifestations (21.0% vs 18.0%, P = 0.68) and prior intestinal surgery (15.1% vs 7.7%, P = 0.29) were comparable. Prior biologic therapy was more common in the HT group (30.3% vs 12.8%, P = 0.03) and remained independently associated after covariate adjustment (adjOR 2.93, 95% CI: 1.05–8.20, P = 0.04). Among 86 older patients followed longitudinally, HT was associated with higher anemia rates (65.2% vs 35.0%, P = 0.02) and remained an independent predictor on multivariate analysis (adjOR 5.31, 95% CI: 1.52-18.58). HT was not a significant predictor of increased healthcare utilization—including colonoscopies (adjIRR 0.91, 95% CI: 0.45–1.81), hospitalizations (adjIRR 0.94, 95% CI: 0.36–2.45), emergency department (ED) visits (adjIRR 1.67, 95% CI: 0.61–4.59), or imaging (adjIRR 1.13, 95% CI: 0.58–2.24). Conclusion: In older adults with IBD, HT was independently associated with prior biologic therapy and increased anemia burden but not greater healthcare utilization. HT may represent a marker of heightened systemic inflammation, warranting early recognition and multidisciplinary management.