U-shaped association between triglyceride-glucose index and all-cause mortality among critically ill pediatrics: a population-based retrospective cohort study

Abstract

Background: Previous studies have shown that an elevated triglyceride-glucose (TyG) index was associated with all-cause mortality in both general adult individuals and critically ill adult patients. However, the relationship between the TyG index and clinical prognosis in pediatric patients admitted to the intensive care unit (ICU) remains unknown. We aimed to investigate the association of the TyG index with in-hospital all-cause mortality in critically ill pediatric patients.

Methods: A total of 5706 patients in the Pediatric Intensive Care database were enrolled in this study. The primary outcome was 30-day in-hospital all-cause mortality, and secondary outcome was 30-day in-ICU all-cause mortality. The restricted cubic spline (RCS) curves and two-piecewise multivariate Cox hazard regression models were performed to explore the relationship between the TyG index and outcomes.

Results: The median age of the study population was 20.5 [interquartile range (IQR): 4.8, 63.0] months, and 3269 (57.3%) of the patients were male. The mean TyG index level was 8.6 ± 0.7. A total of 244 (4.3%) patients died within 30 days of hospitalization during a median follow-up of 11 [7, 18] days, and 236 (4.1%) patients died in ICU within 30 days of hospitalization during a median follow-up of 6 [3, 11] days. The RCS curves indicated a U-shape association between the TyG index and 30-day in-hospital and in-ICU all-cause mortality (both P values for non-linear < 0.001). The risk of 30-day in-hospital all-cause mortality was negatively correlated with the TyG index until it bottoms out at 8.6 (adjusted hazard ratio [HR], 0.72, 95% confidence interval [CI] 0.55-0.93). However, when the TyG index was higher than 8.6, the risk of primary outcome increased significantly (adjusted HR, 1.51, 95% CI 1.16-1.96]). For 30-day in-ICU all-cause mortality, we also found a similar relationship (TyG < 8.6: adjusted HR, 0.75, 95% CI 0.57-0.98; TyG ≥ 8.6: adjusted HR, 1.42, 95% CI 1.08-1.85). Those results were consistent in subgroups and various sensitivity analysis.

Conclusions: Our study showed that the association between the TyG index and 30-day in-hospital and in-ICU all-cause mortality was nonlinear U-shaped, with a cutoff point at the TyG index of 8.6 in critically ill pediatric patients. Our findings suggest that the TyG index may be a novel and important factor for the short-term clinical prognosis in pediatric patients.

Keywords: All-cause mortality; Critically ill; PIC database; Pediatrics; TyG index.

Fig. 1

Flowchart of study population selection

Fig. 2

Relationship between the TyG index and the risk of 30-day in-hospital all-cause mortality and 30-day in-ICU all-cause mortality based on restricted cubic spline curves. TyG triglyceride-glucose, ICU intensive care unit. A 30-day in-hospital all-cause mortality, B 30-day in-ICU all-cause mortality. The model was adjusted for age, sex, ICU types, surgical procedure, congenital valvular heart disease, congenital heart disease, malignant tumors, pneumonia, sepsis, shock, use of vasopressors, white blood cell count, lymphocyte percentage, neutrophil percentage, high sensitivity C reactive protein, serum albumin, total cholesterol, hemoglobin, platelets, blood urea nitrogen, cystatin C, and serum creatinine

Fig. 3

Stratified analyses by potential modifiers of the association between TyG index and 30-day in-hospital all-cause mortality. TyG triglyceride-glucose, ICU intensive care unit, HR hazard ratio, CI confidence interval. A TyG index < 8.6, B TyG index ≥ 8.6. The model was adjusted for age, sex, ICU types, surgical procedure, congenital valvular heart disease, congenital heart disease, malignant tumors, pneumonia, sepsis, shock, use of vasopressors, white blood cell count, lymphocyte percentage, neutrophil percentage, high sensitivity C reactive protein, serum albumin, total cholesterol, hemoglobin, platelets, blood urea nitrogen, cystatin C, and serum creatinine