Sarcopaenia-high visceral fat combo predicts poor outcomes in Crohn’s disease

The combination of sarcopaenia and high visceral fat, rather than individually, is associated with worse outcomes in patients with Crohn’s disease (CD), suggests a recent study.

A team of investigators conducted this retrospective study to assess 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 to December 2015). Patients were followed until December 2019.

Sarcopaenia was defined as SMI <36.5 cm²/m² for males and 30.2 cm²/m² for females. The investigators then compared disease severity, behaviour, and long-term outcomes (surgery and disease course) with respect to sarcopaenia and VF/SC ratio.

Forty-four patients (age at onset 34.4 years, median disease duration 48 months, follow-up duration 32 months, males 63.6 percent) were enrolled in the study.

Sarcopaenia had a 43-percent prevalence in females, independent of age, disease severity, behaviour, and location. More patients with sarcopaenia had surgery (31.6 percent vs 4 percent; p=0.01). Those who underwent surgery had significantly higher VF/SC (1.76 vs 0.9; p=0.002); a cutoff of 0.88 was predictive of surgery, with sensitivity of 71 percent and specificity of 65 percent.

Survival analysis revealed a lower probability of remaining surgery-free among patients with sarcopaenia (59.6 percent vs 94.1 percent; p=0.01) and those with VF/SC >0.88 (66.1 percent vs 91.1 percent; p=0.1). This probability remained lower in patients with both sarcopaenia and VF/SC >0.88 than those with either or none (38 percent vs 82 percent vs 100 percent; p=0.01).

“Sarcopenia and visceral fat independently predict poor outcomes in CD,” the investigators said.