Background: Inflammatory bowel disease (IBD) patients with sarcopenia are at increased morbidity risk. The aim of this study was to assess the prevalence of sarcopenia in IBD outpatients using both morphological and functional criteria.

Methods: In this prospective cohort study, all IBD patients admitted to the day hospital unit between March 01 and 31, 2023 were included. Muscle mass and function were evaluated using bioelectrical impedance analysis and handgrip strength measurement, respectively. Probable sarcopenia was defined as reduced handgrip strength (<16-27 kg). Myopenia was defined by a low appendicular muscle mass index (<5.5-7 kg/m²). Sarcopenia was diagnosed based on the coexistence of reduced muscle strength and muscle mass. Disease activity, therapeutic changes, hospitalizations, and IBD-related surgeries were assessed at month 6.

Results: Sixty patients with either Crohn's disease (CD, 52 %) or ulcerative colitis (48 %), with a median age of 37 years (interquartile range [IQR]: 28-54), were included. Fifty-five percent were women. Most patients were in remission (67 %, n = 40). In CD patients, the involvement was ileocolic (48 %), ileal (35 %), or colonic (16 %). A history of IBD-related digestive surgery was noted in 30 % of cases. The median body mass index [BMI] was 24 (IQR: 21-27). The prevalence of sarcopenia, probable sarcopenia, and myopenia was 10 %, 18 %, and 20 %, respectively. Sarcopenic patients were significantly older (59 vs 36 years, p = 0.01), had a longer disease duration (20 vs 8 years, p = 0.003), were more likely to have associated joint inflammation (27 % vs 6 %, p = 0.01) and CD (80 % vs 49 %, p = 0.36). Myopenia was significantly associated with a history of surgery (67 % vs 21 %, p = 0.004) and a lower BMI (21 vs 24, p = 0.001).

Conclusions: In this prospective cohort of IBD outpatients, 10 % and 20 % of patients had sarcopenia and myopenia, respectively. Screening for sarcopenia therefore seems essential in this population, including in stable outpatients in remission who do not meet malnutrition criteria and in overweight patients, as according to the literature, sarcopenia is associated with poorer clinical outcomes and increased postoperative complications. Interventional studies are needed to assess the impact of multidisciplinary treatment of sarcopenia on quality of life and disease progression.