Prevalence and Impact of Sarcopenia in Patients with Inflammatory Bowel Diseases: a Prospective Cohort Study.

Abstract Background Sarcopenia is associated with increased morbidity and mortality in IBD. The main objective of this study was to prospectively evaluate sarcopenia by combining morphological and functional criteria in an outpatient IBD population. Methods In a prospective cohort study, we included all IBD patients admitted to the Day Hospital (DH) of our department between March 1st and 31st, 2023. Patients with short bowel syndrome were not included. Muscle mass was assessed using a Bodystat®1500MDD dual-frequency impedance meter, and muscle function was assessed by measuring handgrip strength, Carym® digital dynamometer. Pre-sarcopenia was defined by a handgrip measurement < 16 to 26, and myopenia was defined by an appendicular muscle mass index (AMMI) < 5.5 to 7 kg/m2 or a fat-free mass index (FFMI) < 15 to 17 in women or men. Sarcopenia was defined by the association of pre-sarcopenia and myopenia. Patients were followed-up at 6 months to measure a composite criterion of disease activity combining one of the factors: FC > 250µg/g, endoscopic activity, therapeutic change, hospitalization, or IBD-related surgery. Results In total, 60 patients were included, median age 37 years (IQR 28-54), 55% women, with CD (52%) or UC (48%) diagnosed 9 years (4-17) ago, mostly in remission (67%, n=40). Patients with CD had ileocolic (48%), ileal (35%), or colonic (16%) involvement. Patients with UC had E1 (7%), E2 (41%), or E3 (52%) involvement. A history of digestive surgery linked to IBD was noted in 30% of cases. The biologics administered were infliximab (61%), vedolizumab (25%), or ustekinumab (14%). The BMI was 24 (21-27) and serum albumin was 41g/l (39-44). The prevalence of sarcopenia, pre-sarcopenia and myopenia was 10%, 11% and 20%, respectively. Sarcopenic patients were significantly older (59 vs. 36 years, p=0.01), with older disease (20 vs. 8 years, p=0.003), and associated joint damage (40% vs. 2%, p=0.002) and tended to involve CD more frequently (80 vs. 49%, p=0.36). There was no significant difference between biologics, BMI or albuminemia in sarcopenic patients, but vitamin D levels tended to be lower (15 vs. 43, p=0.27). Myopenia was significantly associated with a history of surgery (67 vs. 21%, p=0.004), a lower BMI (21 vs. 24, p=0.001) and a more active disease at M6 according to the composite criterion (50 vs. 21%, p=0.04 after adjustment for age, sex, and disease activity at baseline). Myopenia indices were strongly correlated with handgrip values (r=0.7, p<0.001). Conclusion In a prospective study of Day Hospital IBD patients, sarcopenia was identified by impedancemetry in 11% and myopenia in 20% of cases, and associated with an increase in morbidity.