Association between the triglyceride glucose body mass index and long-term mortality in ICU patients: a cohort study of over 3000 patients

Abstract

Abstract Background The Triglyceride Glucose (TyG) index has recently been considered an accurate surrogate biomarker for assessing insulin resistance (IR). The TyG-BMI index, integrating the Body Mass Index (BMI), has been recognized by numerous studies as a superior representation of IR status. This research aimed to investigate the relationship between the TyG-BMI index and long-term mortality risk in critically ill patients. Methods Patient data for this study were sourced from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, from which the TyG-BMI indexes were extracted. The primary endpoint was all-cause mortality within one year. Kaplan-Meier survival analysis was utilized to compare the primary endpoint across quartiles. Restricted cubic splines and Cox proportional hazards analyses were employed to explore the association between the TyG-BMI index and the endpoint. Results A total of 3,216 patients admitted to the ICU were included in the study. Kaplan-Meier analysis revealed that patients with higher TyG-BMI index values had a significantly reduced risk of death (log-rank P < 0.001). Additionally, restricted cubic spline analysis indicated a U-shaped relationship between the TyG-BMI index and long-term mortality. Furthermore, multivariable Cox proportional hazard analysis showed that the highest quartile of the TyG-BMI index, compared to the lowest quartile, had a hazard ratio (HR) of 0.66(95% CI: 0.46, 0.88; P < 0.001) for one-year mortality, suggesting a protective effect. Conclusions Among critically ill patients, the highest quartile of the TyG-BMI index was associated with a lower rate of long-term mortality. The TyG-BMI index also demonstrated a U-shaped relationship with long-term mortality, suggesting the existence of an optimal TyG-BMI range that may confer protective effects within a certain interval for critically ill patients.