Establishment of a prognostic model for hospitalized cirrhotic patients with infection based on lumbar muscle mass.

Background: Sarcopenia frequently complicates cirrhosis and leads to substantial mortality. Infection is a complication of cirrhosis that results in high mortality. Both sarcopenia and infection are accompanied by systemic inflammation and adversely affect the prognosis of cirrhosis. This article was designed to decipher the association of sarcopenia with infection occurrence, and to ascertain the risk factors for the 90-day death rate in hospitalized cirrhotic patients with infection. Methods: A total of 808 cirrhotic patients (373 with infection and 435 without) who had undergone abdominal CT from 2017 to 2021 were recruited for this retrospective single-center research. The skeletal muscle index was assessed at the level of the third lumbar vertebra (L3 SMI). The optimal cutoff value of the CAIL3 model (CTP score, AKI, INR, and L3 SMI) for the prediction of the 90-day death rate was authenticated with receiver operating characteristic (ROC) analysis. Results: L3 SMI was considered to be the independent risk factor for infection in cirrhotic patients and 90-day death rate in these patients with infection (HR 2.840 95% CI 2.076-3.886, p < 0.001 for infection and HR 2.097 95% CI 1.142-3.850, p = 0.017 for 90-day death rate, respectively). CAIL3 had an area under the ROC curve of 0.840, and a cutoff value of 0.21 for predicting the poor outcome (sensitivity 77.22% and specificity 76.53%, respectively). Conclusion: L3 SMI is an essential factor associated with infection and 90-day death rate in cirrhotic patients. CAIL3 may be a novel model for the prediction of the 90-day death risk in cirrhotic patients with infections.