Evaluation of malnutrition with the help of the GLIM criteria. Muscle mass measurement, as recommended in the GLIM criteria was done with the help of abdominal CT scan and BIA. Both methods were compared and their association to the clinical outcome was assessed.

We retrospectively analysed 260 patients undergoing major abdominal surgery between January 2017 and December 2019. Patients were prospectively screened and assessed for malnutrition with Nutritional Risk Score (NRS) and Subjective Global assessment (SGA). Body composition was analysed with CT scan and BIA within 30 days before surgery. GLIM criteria were retrospectively determined referring to the Fat free Mass from BIA (FFMBIA) and Muscle Mass from axial CT scan at lumbar level 3 (MMCT). The prevalence of GLIM - malnutrition according to BIA and CT was evaluated. Multivariate logistic regression analysis was used to determine association between malnutrition and outcome parameters. ROC-curves specified sensitivity and specificity of the different tools and areas under the curve were calculated.

Inclusion Criteria:

• age above 18 years
• BIA and CT scan was available within 31 days before surgery
• patients undergoing major abdominal surgery for gastrointestinal cancer

Exclusion Criteria:

• patients who were not able to agree to the participation
• missing assessment of the nutritional status
• leck of quality of the CT scan

Patients undergoing major abdominal surgery for gastrointestinal cancer