Non-linear association between aspartate aminotransferase to alanine aminotransferase ratio and mortality in critically ill older patients: A retrospective cohort study

• Published in: PloS one 2023-11, Vol.18 (11), p.e0293749-e0293749
• Main Authors: Yang, Hua, Meng, Limin, Xin, Shuanli, Chang, Chao, Zhao, Xiufeng, Guo, Bingyan
• Format: Article
• Language: English
• Subjects: Age; Aged; Aged patients; Alanine; Alanine aminotransferase; Alanine Transaminase; Analysis; Aspartate; Aspartate aminotransferase; Aspartate Aminotransferases; Biology and Life Sciences; Blood pressure; Cardiac arrest; Care and treatment; Cerebrovascular disease; Cohort analysis; Complications and side effects; Critical Illness; Critically ill; Diabetes; Female; Heart attacks; Heart failure; Hemoglobin; Hospital patients; Hospitals; Humans; Hypertension; Intensive care; Ischemia; Kidneys; Liver Diseases; Male; Medical advice systems; Medical research; Medicine and Health Sciences; Medicine, Experimental; Mortality; Older people; Oxidative stress; Patient outcomes; Patients; Physical Sciences; Potassium; Regression analysis; Research and Analysis Methods; Retrospective Studies; Sepsis; Structured Query Language-SQL; Subgroups; Survival analysis; Transaminases; Type 2 diabetes
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0293749

The aspartate aminotransferase to alanine aminotransferase (AST/ALT) ratio has been shown to be associated with poor clinical outcomes across various patient groups. However, little is unclear about the association between the two in critically ill older patients. Therefore, we aim to investigate the association of the AST/ALT ratio with hospital mortality in this special population. In this retrospective cohort study, we extracted elderly patients (age ≥ 65 years) from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The primary outcome was in-hospital mortality. The association between the AST/ALT ratio and hospital mortality was studied using univariable and multivariable Cox regression analysis, as well as restricted cubic splines (RCS). Survival analysis was performed using the Kaplan-Meier (KM) method according to the AST/ALT ratio. Among the 13,358 eligible patients, the mean age was 77.6 years, 7,077 patients (52.9%) were male, and 2,511 patients (18.8%) died in hospital. The AST/ALT ratio was found to be independently associated with in-hospital mortality (HR = 1.05, 95% CI: 1.01-1.09, P = 0.022) after adjusting for potential confounders. Furthermore, a non-linear relationship and saturation effect were observed between them, with the inflection point being 1.80. When the AST/ALT ratio was less than 1.80, we found that every 1 unit increase in the AST/ALT ratio resulted in a 39% increased risk of in-hospital mortality (HR = 1.39, 95% CI: 1.18-1.64, P < 0.001). However, when the AST/ALT ratio was greater than 1.80, the association became saturated (HR = 1.01, 95% CI: 0.96-1.07, P = 0.609). Sensitivity and subgroup analyses showed the results were robust. In critically ill older patients, the association between the AST/ALT ratio and in-hospital mortality was non-linear and showed a saturation effect. An elevated AST/ALT ratio was significantly associated with increased in-hospital mortality when the AST/ALT ratio was less than 1.80.