Combination of sarcopenia and high visceral fat predict poor outcomes in patients with Crohn's disease

Background: Sarcopenia and visceral fat independently predict poor outcomes in Crohn's disease (CD). However, combined influence of these parameters on outcomes is unknown, and was investigated in the present study.

Methods: This retrospective study evaluated skeletal muscle index (SMI-cross-sectional area of five skeletal muscles normalized for height), visceral and subcutaneous fat area and their ratio (VF/SC) on single-slice computed tomography (CT) images at L3 vertebrae in CD patients (CT done: January 2012-December 2015, patients followed till December 2019). Sarcopenia was defined as SMI < 36.5 cm²/m² and 30.2 cm²/m² for males and females, respectively. Disease severity, behavior, and long-term outcomes (surgery and disease course) were compared with respect to sarcopenia and VF/SC ratio.

Results: Forty-four patients [age at onset: 34.4 ± 14.1 years, median disease duration: 48 (24-95) months, follow-up duration: 32 (12-53.5) months, males: 63.6%] were included. Prevalence of sarcopenia was 43%, more in females, but independent of age, disease severity, behavior and location. More patients with sarcopenia underwent surgery (31.6% vs 4%, p = 0.01). VF/SC was significantly higher in patients who underwent surgery (1.76 + 1.31 vs 0.9 + 0.41, p = 0.002), and a cutoff of 0.88 could predict surgery with sensitivity and specificity of 71% and 65% respectively. On survival analysis, probability of remaining free of surgery was lower in patients with sarcopenia (59.6% vs 94.1% p = 0.01) and those with VF/SC > 0.88 (66.1% vs 91.1%, p = 0.1), and still lower in those with both sarcopenia and VF/SC > 0.88 than those with either or none (38% vs 82% vs 100%, p = 0.01).

Conclusions: Combination of sarcopenia and high visceral fat predict worse outcomes in CD than either.