Triglyceride-glucose index and mortality in critically ill patients with cardiovascular-kidney-metabolic syndrome stage 4

The triglyceride-glucose (TyG) index is a well-established surrogate marker of insulin resistance (IR). Previous studies have linked higher TyG levels to an increased risk of cardiovascular events in individuals with early-stage (0-3) Cardiovascular-Kidney-Metabolic Syndrome (CKM). However, its prognostic value in critically ill patients with CKM stage 4 remains unclear. In this retrospective study, we analyzed clinical data from critically ill CKM stage 4 patients in the MIMIC-IV database. The TyG index was calculated and patients were categorized into tertiles. Cox proportional hazards models and restricted cubic spline (RCS) analyses were used to evaluate the association between the TyG index and all-cause mortality. A total of 3,125 patients were included, of whom 65.22% were male.= The 1-year all-cause mortality was 34.18% overall (28.79% in Q1, 35.06% in Q2, and 38.68% in Q3; P < 0.05). In multivariable Cox regression, each 1-standard deviation increase in the TyG index was associated with a 23% higher risk of 1-year mortality (HR = 1.23, 95% CI 1.09-1.39). Compared with the Q1 group, patients in Q3 had a 30% higher 1-year mortality risk (HR = 1.30, 95% CI 1.08-1.55). RCS analysis showed a linear positive relationship between the TyG index and mortality (P for non-linearity > 0.05). These findings indicate that higher TyG levels are independently associated with increased short- and long-term mortality in critically ill patients with CKM stage 4. The TyG index may provide a simple indicator of acute metabolic disturbances and could support early risk stratification in this population. However, its role in clinical decision-making and potential utility in guiding interventions require confirmation in prospective studies.