S3052 Microscopic Colitis in Celiac Patients: A Hidden Driver of Malnutrition and Healthcare Utilization

Introduction: Microscopic colitis (MC) is increasingly recognized as a comorbidity in patients with celiac disease (CD), particularly among those with persistent symptoms despite a gluten-free diet. However, the impact of coexisting MC on CD clinical outcomes remains underexplored. We aimed to evaluate the burden of malnutrition, healthcare utilization, and malignancy in patients with CD and concurrent MC (CD + MC) compared to those with isolated CD. Methods: Using the TriNetX Global Research Network, we identified adult patients with CD only and matched them 1:1 with patients with CD + MC (n = 2,833 per group) based on age, sex, and comorbidities. We evaluated the incidence of malnutrition, emergency department (ED) visits, hospitalizations, and all-cause mortality. Hazard ratios (HRs) with 95% confidence intervals (CIs) and P-values were used to compare outcomes. Results: Patients with CD + MC had a significantly higher risk of malnutrition compared to those with isolated CD (HR 0.71, 95% CI: 0.58–0.86; P = 0.001). ED visits and hospitalizations were modestly reduced in the CD + MC group (HR 0.88, 95% CI: 0.80–0.96; P = 0.006). Conclusion: Compared to patients with isolated CD, those with coexisting MC have a significantly greater risk of malnutrition, likely driven by chronic diarrhea, accelerated intestinal transit, and compounded nutrient loss, despite the colon not being a primary site for nutrient absorption. Healthcare utilization was comparable or modestly lower, and mortality risk was not significantly different. Clinicians should maintain a high index of suspicion for MC in CD patients with persistent symptoms and proactively assess for nutritional deficiencies.