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.

背景：克罗恩病（Crohn's disease, CD）患者伴发高内脏脂肪组织（visceral adipose tissue, VAT）及潜行脂肪（creeping fat, CrF）的情况已得到广泛认可。内脏脂肪与皮下脂肪组织（subcutaneous adipose tissue, SAT）的比值以及肌肉减少症均与CD并发症相关。目前针对通过磁共振肠造影（magnetic resonance enterography, MRE）评估的身体成分指标对CD并发症影响的研究仍较为匮乏。
目的：本研究旨在评估基于机会性磁共振肠造影的身体成分参数与潜行脂肪，将其作为复杂性CD的预测指标。
方法：本研究为回顾性研究，共纳入114例CD患者，其中炎症型54例、复杂型60例。研究对患者的身体成分进行半自动评估，并对潜行脂肪进行定性评价。
结果：两组患者在体重指数（body mass index, BMI，p=0.50）、总脂肪组织指数（total adipose tissue index, TATI，p=0.14）、皮下脂肪组织指数（subcutaneous adipose tissue index, SATI，p=0.17）、内脏脂肪组织指数（visceral adipose tissue index, VATI，p=0.33）、VAT/SAT比值（p=0.77）、肌肉内脂肪组织（intramuscular adipose tissue, IMAT，p=0.64）、骨骼肌指数（skeletal muscle index, SMI，p=0.22）及肌肉减少症（p=0.50）方面的身体成分参数均无统计学差异。本研究共检出47例狭窄、18例瘘管及7例脓肿。存在潜行脂肪的患者发生瘘管的风险更高（比值比[OR]=5.07，95%置信区间[CI]=1.76~14.56；p<0.001），高VAT/SAT比值的患者发生瘘管的风险同样更高（OR=3.82，95%CI=1.34~10.85；p=0.01）。
结论：克罗恩病患者的身体成分测量结果在炎症型与复杂型两组间未表现出统计学差异。尽管如此，VAT/SAT比值偏高且存在潜行脂肪的CD患者应被视为发生瘘管的高危人群。