Triglyceride-Glucose Index Associated With Mortality Risk Among Critically Ill Patients

The triglyceride-glucose (TyG) index is independently and positively associated with a higher risk for all-cause mortality among patients who are critically ill, according to study findings in Cardiovascular Diabetology.

The TyG index is a marker of insulin resistance that varies greatly among patients in the intensive care unit (ICU). Monitoring changes in the TyG index can help identify stress responses in the body within these patients. Researchers conducted a retrospective cohort study to assess the associations between changes in the TyG index and all-cause mortality. 

Data were collected from the Medical Information Mart for Intensive Care IV (MIMIC-IV version 2.0), which includes healthcare data on 53,150 patients treated at Beth Israel Deaconess Medical Center from 2008 to 2019. Of note, none of the study participants contracted COVID-19 during the study period. 

The primary outcome was 1-year all-cause mortality. Secondary outcomes included need for mechanical ventilation, length of stay in the ICU and hospital, and in-hospital all-cause mortality.

Baseline characteristics were presented in quartiles, based on the TyG index of the patient on their first day in the ICU. Analysis of in-hospital and 1-year all-cause mortality was assessed at 4 percentiles. One-year all-cause mortality was assessed using the TyG index and TyG variability ratio (TyGVR).

The study population included patients aged at least 18 years who were admitted to the ICU. A total of 8392 patients were included in the analysis and divided into 2 groups based on the TyG index at baseline. The average age of study participants was 64.44 (standard deviation [SD], 16.39) years, 57.21% were men, and the average TyG index was 9.02 (SD, 0.81). 

Of the 3010 (35.87%) deaths identified in the study, 2477 (29.52%) occurred within the first year.

Patients with a higher TyGVR had an increased risk for 1-year all-cause mortality compared against patients with a lower TyGVR (Q1, 30.86% vs Q2, 36.28% vs Q3, 37.82% vs Q4, 42.33%; log-rank P =.007). There were no significant differences observed among TyG index groups (Q1, 27.64% vs Q2, 28.75% vs Q3, 26.50% vs Q4, 27.58%; log-rank P =.593). Similar findings were reported among the matched cohort. 

There was a near-linear association observed between TyGVR and risk for in-hospital all-cause mortality when conducting a restricted cubic spline analysis (Non-linear P =.449; Overall P =.004). A similar near-linear association was also reported between TyGVR and risk for 1-year all-cause mortality (Non-linear P =.909; Overall P =.019).

Study limitations include the small sample size, lack of information on patients’ diets, and the inability to document the cause of death. 

The researchers concluded, “[O]ur study addresses the gap in knowledge regarding the dynamic changes of TyG, a simple biomarker that may reflect the state of illness, which can aid in optimizing in-hospital and long-term risk stratification of mortality. This information is essential for better clinical management and reducing future mortality events.”