CT-based sarcopenia assessment: Predicting outcomes in acute infection patients

In this retrospective cohort study, we investigated the prognostic value of sarcopenia evaluated by Computed Tomography (CT)-based indices for adverse hospitalization outcomes in patients with acute infections. We analyzed data from 225 patients admitted to the hospital for acute infections between 2019 and 2020. Patients who had undergone an abdominal CT scan either up to 1 month before or within the first 3 days of hospitalization were included. CT image analysis was used to evaluate skeletal muscle mass (by skeletal muscle index (SMI)) and muscle quality (by psoas muscle density, pMD). Low pMD was associated with higher in-hospital mortality (31% vs 11.4% p < 0.001) as well as higher longer-term mortality rates (p = 0.008 for 30 days and <0.001 for 90- and 1-year mortality). Low pMD remained an independent poor prognostic factor after controlling for confounders, with an adjusted odds ratio (aOR) of 2.74, (95% CI 1.33-5.67, p = 0.006) for 1-year mortality, and aOR of 2.61, (95% CI 1.23-5.55) for a prolonged hospital stay. Low SMI was associated with adverse outcomes, although this association was not independent after controlling for confounders. Notably, patients with both low SMI and pMD exhibited the poorest hospitalization outcomes: aOR for 1-year mortality 5.015 (95% CI 1.767-14.23, p = 0.002), and prolonged length of stay aOR 3.197, (95% CI 1.159-8.821, p = 0.025). CT-based muscle indices serve as independent prognostic factors in medical patients admitted with acute infection. Incorporating radiological assessments of sarcopenia into routine care for hospitalized patients with acute infection may enable risk stratification and early intervention in reversible conditions.