P101 SARCOPENIA IS ASSOCIATED WITH INCREASED RISK OF INFECTION IN IBD PATIENTS OLDER THAN 50 YEARS STARTING BIOLOGIC MEDICATIONS

The relationship between sarcopenia and clinical outcomes outside of the post-operative setting has not been well-studied in IBD patients. We aimed to characterize the prevalence of sarcopenia and its association with adverse events and clinical response in IBD patients starting on new biologic medications.

We identified a retrospective cohort of adult (≥18 years old) IBD patients at the University of Minnesota with an abdominal CT or MRI within 6 months prior to or one month after starting a new biologic medication. Baseline demographics, disease severity (based on Physician’s Global Assessment from GI encounters), laboratory values and clinical outcomes for one year after the start of medications were obtained from chart review. The primary endpoint was incidence of adverse events (defined as infection, need for surgery, or hospitalization) within one year after medication start. The secondary outcome was clinical response as assessed based on clinical, endoscopic, and radiographic follow-up. Skeletal muscle index (SMI) measures were obtained from CT/MRI images at the L3 vertebral level. Published cut-offs (SMI of 38.5 cm2/m2 for women and 52.4 cm2/m2 for men) were used to determine the presence of sarcopenia. Associations between sarcopenia and outcomes were analyzed using logistic regression and age stratification was performed.

Ninety-four patients (74 CD, 20 UC, 47% male, mean age 38 years) were included in the analysis. The majority of patients had moderate disease severity or worse (83%) at the time of medication start, and 75% were started on anti-TNF medications. Overall prevalence of sarcopenia was 57% (57% CD, 60% UC). In the entire cohort, sarcopenia was not associated with increased rates of adverse events (OR = 0.516, 95% CI 0.217–1.225; p= 0.1334). However, in patients ≥ 50 years of age (n=23), those with sarcopenia had higher risk of infection at 1 year compared to those without sarcopenia (85% vs. 20%; OR = 21.99, 95% CI 3.086–262.515; p = 0.0051). The majority of infections were those that required antibiotics or antivirals, but not hospitalization. Examples included sinusitis, upper respiratory infections, periodontitis, urinary tract infection, herpes simplex, and two cases of C. difficile. Furthermore, when controlling for disease duration and concomitant steroid use, the association between sarcopenia and infection remained significant. In this age subgroup, there was no association between sarcopenia and clinical response to therapy.

In our cohort, sarcopenia was present in the majority of adult IBD patients starting new biologic medications. In patients ≥ 50 years old, sarcopenia was associated with an increased risk of infections. Further work is needed to validate these findings and to understand which patients may benefit from sarcopenia assessment prior to biologic start.