Sarcopenia measurements and clinical outcomes in Crohn's disease surgical patients

Patients with Crohn's disease (CD) have a high likelihood of being sarcopenic. Several studies have shown a positive correlation between sarcopenia measured as skeletal muscle index (SMI) and poor surgical outcomes in patients with CD. Our primary aim was to correlate SMI with the psoas muscle index (PMI), an easier measurement of sarcopenia. Secondary aim was to correlate SMI and PMI with clinical outcomes in a cohort of CD patients requiring surgery.

A retrospective cohort study of CD patients who underwent surgery at a public health service from January 2010 to December 2019. Using computed tomography and magnetic resonance enterography studies, skeletal muscle area was measured at the third lumbar vertebra level. SMI and PMI were calculated and correlated. Correlation between SMI and PMI with surgical outcomes was performed.

Seventy-six patients were included. Median length of stay (LOS) was 6 days (IQR, 5 to 9). Eleven patients (14.5%) required ICU admission, nine patients (11.8%) required TPN and thirteen patients (17.1%) had complications. The prevalence of sarcopenia was 63.2% based on the SMI threshold of 52.4 and 38.5 cm² /m² for men and women, respectively. A positive correlation between SMI and PMI was found (r = 0.72, P < 0.0001). Sarcopenia status based on reported thresholds for SMI and for PMI showed no significant correlation with outcomes (LOS, ICU admission and complications).

SMI and PMI show good correlation but there is insufficient evidence to suggest that sarcopenia status using either measurement has a significant impact on predicting clinical outcomes.