Bali, Aman

Background and Aims: Sarcopenia (SP) is increasingly recognized as a poor prognostic factor for patients with Crohn’s disease (CD). We aimed to use radiographically-measured SP to determine a disease-specific definition and measure its association with CD-related outcomes. Methods: This retrospective study included adults with CD seen at our outpatient tertiary center between 2019 and 2021 who underwent a CT scan within 3 months of visit. Using axial cross-sectional measurements at the L3 vertebral level, skeletal muscle area was indexed to height to derive skeletal muscle index (SMI). Demographics, comorbidities, CD phenotype, and outcomes, including hospitalization at 1 year, were analyzed in univariate and multivariate models. Results: One hundred twenty-four patients with CD were included, with a mean age of 52.2±16.6 years and 53.2% (66/124) women. Overall, 33.1% (41/124) had SP based on sex-specific cutoffs with men representing 75.6% (31/41) of the sarcopenic population. In bivariate analysis, patients with SP had a higher likelihood of hospitalization (43.9% vs. 22.9% for non-SP, P =0.02) and penetrating CD phenotype (20.0% vs. 2.3% for non-SP, P <0.05). On multivariate regression, higher SMI was associated with decreased hospitalization, with each 10-unit increase in SMI conferring 0.54 lower odds (OR: 0.54 [95% CI: 0.32-0.92], P =0.02). Patients with higher SMI trended towards lower use of biologics (OR: 0.70 [95% CI: 0.45-1.09], P =0.12). Our novel SP definition derived from an IBD population performed similarly to definitions from the literature. Conclusion: Our study demonstrates the application of an automated algorithm for the quantification of body composition based on CT scan in patients with CD. SP and low SMI were associated with increased hospitalization at 1 year.