Nonlinear association between AST/ALT ratio and 28-day all-cause mortality following ICU admission in critically ill cirrhotic patients: a retrospective cohort study

Abstract Background The AST/ALT ratio is a biochemical marker associated with poor clinical outcomes in various patients, but its role in severe cirrhosis is unclear. This study investigated the relationship between the AST/ALT ratio and mortality in the intensive care unit (ICU) patients with cirrh...

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Main Authors: Zhigang Xu, Baohong Xu
Format: Article
Language:English
Published: BMC 2025-05-01
Series:BMC Gastroenterology
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Online Access:https://doi.org/10.1186/s12876-025-03966-0
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author Zhigang Xu
Baohong Xu
author_facet Zhigang Xu
Baohong Xu
author_sort Zhigang Xu
collection DOAJ
description Abstract Background The AST/ALT ratio is a biochemical marker associated with poor clinical outcomes in various patients, but its role in severe cirrhosis is unclear. This study investigated the relationship between the AST/ALT ratio and mortality in the intensive care unit (ICU) patients with cirrhosis. Methods This retrospective cohort study analyzed 2,090 liver cirrhosis patients from the MIMIC-IV database, focusing on their first ICU admission between 2008 and 2019. The AST/ALT ratio, measured within 24 h of admission, was the exposure variable, and the main outcome was 28-day mortality. A multivariable logistic regression model evaluated the link between the AST/ALT ratio and mortality. Nonlinear relationships were explored using smooth curve fitting and saturation effect analyses. Stratified analyses and interaction tests were also performed based on demographic and clinical characteristics. Results The study involved 2,090 critically ill liver cirrhosis patients, averaging 59.1 years old, with 65% male and a 28-day post-ICU admission mortality rate of 29%. The AST/ALT ratio was linked to mortality risk (adjusted odds ratio (OR) 1.1, 95% confidence interval (CI) 1.0–1.2; p = 0.015), showing a nonlinear pattern with a critical point at 3.6. Below this, each unit increase raised mortality risk by 40% (adjusted OR 1.4, 95% CI 1.2–1.6, p < 0.001), but the effect plateaued beyond this level (adjusted OR 1.0, 95% CI 0.8–1.1, p = 0.600). Subgroup analyses confirmed the consistent association, with interaction P values over 0.05. Conclusions The AST/ALT ratio is an independent predictor of 28-day mortality in critically ill cirrhotic patients, with a nonlinear relationship (risk increases up to a ratio of ~ 3.6, then plateaus). This marker could enhance ICU risk stratification and inform clinical decision-making.
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spelling doaj-art-b48d899ebf1d44d7894aec937f7a38852025-08-20T03:53:58ZengBMCBMC Gastroenterology1471-230X2025-05-0125111110.1186/s12876-025-03966-0Nonlinear association between AST/ALT ratio and 28-day all-cause mortality following ICU admission in critically ill cirrhotic patients: a retrospective cohort studyZhigang Xu0Baohong Xu1Department of Gastroenterology, Beijing Luhe Hospital Affiliated to Capital Medical University, Tongzhou DistrictDepartment of Gastroenterology, Beijing Luhe Hospital Affiliated to Capital Medical University, Tongzhou DistrictAbstract Background The AST/ALT ratio is a biochemical marker associated with poor clinical outcomes in various patients, but its role in severe cirrhosis is unclear. This study investigated the relationship between the AST/ALT ratio and mortality in the intensive care unit (ICU) patients with cirrhosis. Methods This retrospective cohort study analyzed 2,090 liver cirrhosis patients from the MIMIC-IV database, focusing on their first ICU admission between 2008 and 2019. The AST/ALT ratio, measured within 24 h of admission, was the exposure variable, and the main outcome was 28-day mortality. A multivariable logistic regression model evaluated the link between the AST/ALT ratio and mortality. Nonlinear relationships were explored using smooth curve fitting and saturation effect analyses. Stratified analyses and interaction tests were also performed based on demographic and clinical characteristics. Results The study involved 2,090 critically ill liver cirrhosis patients, averaging 59.1 years old, with 65% male and a 28-day post-ICU admission mortality rate of 29%. The AST/ALT ratio was linked to mortality risk (adjusted odds ratio (OR) 1.1, 95% confidence interval (CI) 1.0–1.2; p = 0.015), showing a nonlinear pattern with a critical point at 3.6. Below this, each unit increase raised mortality risk by 40% (adjusted OR 1.4, 95% CI 1.2–1.6, p < 0.001), but the effect plateaued beyond this level (adjusted OR 1.0, 95% CI 0.8–1.1, p = 0.600). Subgroup analyses confirmed the consistent association, with interaction P values over 0.05. Conclusions The AST/ALT ratio is an independent predictor of 28-day mortality in critically ill cirrhotic patients, with a nonlinear relationship (risk increases up to a ratio of ~ 3.6, then plateaus). This marker could enhance ICU risk stratification and inform clinical decision-making.https://doi.org/10.1186/s12876-025-03966-0CirrhosisAST/ALT ratioICU mortalityPrognosisNonlinear association
spellingShingle Zhigang Xu
Baohong Xu
Nonlinear association between AST/ALT ratio and 28-day all-cause mortality following ICU admission in critically ill cirrhotic patients: a retrospective cohort study
BMC Gastroenterology
Cirrhosis
AST/ALT ratio
ICU mortality
Prognosis
Nonlinear association
title Nonlinear association between AST/ALT ratio and 28-day all-cause mortality following ICU admission in critically ill cirrhotic patients: a retrospective cohort study
title_full Nonlinear association between AST/ALT ratio and 28-day all-cause mortality following ICU admission in critically ill cirrhotic patients: a retrospective cohort study
title_fullStr Nonlinear association between AST/ALT ratio and 28-day all-cause mortality following ICU admission in critically ill cirrhotic patients: a retrospective cohort study
title_full_unstemmed Nonlinear association between AST/ALT ratio and 28-day all-cause mortality following ICU admission in critically ill cirrhotic patients: a retrospective cohort study
title_short Nonlinear association between AST/ALT ratio and 28-day all-cause mortality following ICU admission in critically ill cirrhotic patients: a retrospective cohort study
title_sort nonlinear association between ast alt ratio and 28 day all cause mortality following icu admission in critically ill cirrhotic patients a retrospective cohort study
topic Cirrhosis
AST/ALT ratio
ICU mortality
Prognosis
Nonlinear association
url https://doi.org/10.1186/s12876-025-03966-0
work_keys_str_mv AT zhigangxu nonlinearassociationbetweenastaltratioand28dayallcausemortalityfollowingicuadmissionincriticallyillcirrhoticpatientsaretrospectivecohortstudy
AT baohongxu nonlinearassociationbetweenastaltratioand28dayallcausemortalityfollowingicuadmissionincriticallyillcirrhoticpatientsaretrospectivecohortstudy