Low thoracic skeletal muscle is a risk factor for 6-month mortality of severe community-acquired pneumonia in older men in intensive care unit.

ABSTRACT

BACKGROUND: Patients with severe community-acquired pneumonia (sCAP) admitted to the intensive care unit (ICU) often exhibit muscle catabolism, muscle weakness, and/or atrophy, all related to an increased morbidity and mortality. However, the relationship between thoracic skeletal muscle mass and sCAP-related mortality has not been well-studied. Early recognition of sarcopenia in ICU patients with sCAP would benefit their prognosis. METHODS: A retrospective study was conducted in Taizhou Hospital of Zhejiang Province, involving 101 patients with sCAP admitted in the ICU between December 2022 and February 2023. We measured the cross-sectional aera of the pectoralis, intercostal, paraspinal, serratus, and latissimus muscles at the T4 vertebral level (T4CSA) using chest computed tomography. Discriminatory thresholds were established by performing receiver operating characteristic curve analysis, with a designated cutoff value of 96.75 cm2 for male patients. This cohort was classified into mortality and survival groups based on a 6-month post-admission outcome. Univariate and multifactorial logistic regression analyses were performed to validate the correlation between low thoracic skeletal muscle area and prognostic outcomes. RESULTS: The mean age of the patients was 75.39 ± 12.09 years, with an overall 6-month mortality of 73.27%. T4CSA of the 6-month survival group was significantly larger than that in the mortality group for overall cohort. The T4CSA in the survival group was significantly larger than that in the mortality group (104.29 ± 23.98cm2 vs. 87.44 ± 23.0cm2, p = 0.008). T4CSA predicted the 6-month mortality from sCAP in males with an AUC of 0.722 (95% confidence interval (CI), 0.582-0.861). The specificity and sensitivity were 71.4% and 71.1%, respectively, (p < 0.05). No significant difference was observed between the two groups in terms of T4CSA. CONCLUSIONS: This study revealed that low thoracic skeletal muscle mass increased the risk of all-cause 6-month mortality in ICU patients with sCAP, particularly among male patients.