P644 Body composition does not predict clinical course in patients with acute severe ulcerative colitis

Abstract Background Acute Severe Ulcerative Colitis (ASUC) is a life-threatening complication of UC. Previous research has shown that body composition parameters, including sarcopaenia, are associated with outcomes in IBD. However, the relationship between body composition and the clinical outcomes of patients hospitalised with ASUC has not yet been clearly defined. We sought to further evaluate the prognostic role of body composition and further explore predictors of clinical outcome in ASUC. Methods We performed a cohort study of hospitalised ASUC patients. Body composition was assessed using fat and muscle segmentation, at the level of the L3 vertebral body, in patients who underwent abdominal computed tomography (CT) during hospitalisation. We defined sarcopenia according to skeletal muscle index (SMI) < 38 cm2/m2 in females and < 42 cm2/m2 in males. Clinical endpoints included length of hospitalisation, need for rescue medical therapy or colectomy. Between group comparisons were performed and logistic regression was used for risk factor analysis. Results We studied 116 patients with ASUC, 51 of whom underwent abdominal CT imaging during their hospitalisation. Median age was 32 years and 64% of patients were female. Sixty-two patients (53.5%) required rescue medical therapy. Rescue medical therapy was successful in 48 patients (77.4%) and 14 patients (22.6%) required an inpatient colectomy. Patients who underwent CT imaging during admission required increased rescue medical therapy (66.7% vs 43.1%, p=0.02) and were hospitalised for longer (11 vs 6 days, p