O005 - ASSOCIATION BETWEEN SKELETAL MUSCLE INDEX AND 30-DAY MORTALITY IN ICU PATIENTS

O005

ASSOCIATION BETWEEN SKELETAL MUSCLE INDEX AND 30-DAY MORTALITY IN ICU PATIENTS

A. De Watteville^1,2,3,*, C. P. Heidegger ^2,4, J. Falciola⁵, C. Graf^5,6, V. A. Bertoni Maluf¹, C. M. Prado ⁷, T.-H. Collet^6,8, Y. M. Dupertuis¹, A. Platon^6,9, L. Genton ^1,6

¹Clinical Nutrition, Division of Gastroenterology, Hepatology & Nutrition , ²Division of Intensive Care, Department of Acute Care Medicine, ³Care Directorate , Geneva University Hospitals , ⁴Department of anaesthesiology, pharmacology, intensive care and emergency medicine, University of Geneva, ⁵Division of Geriatrics, Geneva University Hospitals , ⁶Faculty of Medicine, University of Geneva, Geneva , Switzerland, ⁷Department of Agricultural, Food and Nutritional Science, University of Alberta, Alberta, Canada, ⁸Division of Endocrinology, Diabetology and Metabolism, Department of Medicine , ⁹Division of Radiology, Geneva University Hospitals , Geneva , Switzerland

Rationale: Critically ill patients are prone to rapid muscle loss due to inflammation, immobilization, and stress. Assessment of muscle mass in this population is challenging due to mobility and fluid shifts. This study evaluated the association between skeletal muscle index (SMI) measured by computed tomography (CT) and 30-day mortality.

Methods: Patients ≥18 years admitted to the Geneva intensive care unit (ICU) between 2010 and 2022 with an abdominal CT performed between 48 hours before and 96 hours after ICU admission were included. Skeletal muscle cross-sectional area at L3 was assessed using automated AI software DAFS (Voronoi^®) and divided by height (m)² to calculate SMI. Multivariable Cox Lasso regression models for 30-day mortality were performed separately by sex and included quartiles of SMI, visceral (VAT), subcutaneous (SAT), and intermuscular (IMAT) adipose tissue indices, where quartile 1, reference category, corresponded to the lowest value. Models were adjusted for age, SAPS II, admission date, and primary diagnosis. 

Results: A total of 3342 CT scans were analyzed (32% women). Women had lower SMI and VAT (38.1 vs 47.0 and 34.5 vs.50.0 cm²/m², respectively, both p<0.001) but higher SAT and IMAT (74.2 vs 48.7 and 3.5 vs 2.9 cm²/m² respectively, both p<0.001). In both sexes, individuals in the lowest SMI quartile were older, had higher SAPS II, and lower BMI. Higher SMI quartiles were associated with lower 30-day mortality.

Table 1. Association between SMI &30-day mortality

Conclusion: Higher SMI was significantly associated with lower 30-day mortality. Adipose tissue compartments were not associated with mortality. CT-derived body composition may provide prognostic information beyond BMI in ICU patients.

Disclosure of Interest: None declared