Supplementary Material for: Body composition predictors of complicated Crohn’s disease

Background: High visceral adipose tissue (VAT) and creeping fat (CrF) in Crohn's disease (CD) have been widely recognized. The VAT to subcutaneous adipose tissue (SAT) ratio and sarcopenia have been associated with CD complications. Studies regarding the influence of body composition predictors on CD complications assessed with magnetic resonance enterography (MRE) are scarce. Aim: Assessment of the body composition parameters and CrF in opportunistic MRE as predictors of complicated CD. Methods: This was a retrospective study of 114 patients with inflammatory (n = 54) and complicated (n = 60) CD. The semi-automated assessment of body composition and the qualitative evaluation of CrF were performed. Results: Body composition parameters did not differ between both groups regarding the body mass index (BMI) (p =0.50), total adipose tissue index (TATI) (p =0.14), subcutaneous adipose tissue index (SATI) (p =0.17), visceral adipose tissue index (VATI) (p =0.33), VAT/SAT ratio (p =0.77), intramuscular adipose tissue (IMAT) (p =0.64), skeletal muscle index (SMI) (p =0.22), and sarcopenia (p =0.50). 47 strictures, 18 fistulae, and seven abscesses were identified. Fistulae were more likely to occur in patients with CrF (odds ratio [OR] 5.07, 95% confidence interval [CI] 1.76–14.56; p=<0.001) and high VAT/SAT ratio (OR: 3.82, 95% CI 1.34–10.85; p=0.01). Conclusion: Body composition measurements in CD patients displayed no statistically significant difference between the groups of inflammatory and complicated disease. Nonetheless, CD patients stratified in the group of high VAT/SAT ratio and the presence of CrF should be recognized as risk groups for the occurrence of fistulae.