A cross-sectional study on triglyceride-glucose index as predictor of in-hospital mortality in ACS-MI patients

Tóm tắt

Background: Cardiovascular diseases (CVD) in the Philippines are still among the leading causes of morbidity and was the 2021 leading cause of mortality in the preliminary report by the Philippine Statistics Office. Insulin resistance, which is linked to cardiovascular risk factors such hyperglycemia, dyslipidemia, and hypertension, is one of the variables that significantly contributes to CVD.

The hyperinsulinemic-euglycemic clamp, is regarded as the gold-standard method to measure insulin sensitivity in vivo. This is an invasive and labor-intensive infusion of insulin and glucose, titrated to determine insulin resistance. The triglyceride-glucose index (TGI), which is calculated using fasting triglyceride and fasting blood glucose measurements, has been proposed as a simple and low-cost marker of insulin resistance. 

Because the Triglyceride-Glucose Index may serve as a suitable indicator of insulin resistance, this study can establish it as a useful tool in predicting outcomes such as in-hospital mortality in patients with ACS-MI.

Methods: This is a two-year single-center cross-sectional study of 132 ACS-MI patients admitted at our institution. Samples were taken within the first 48 hours of admission. Triglyceride-glucose Index of the subjects was computed as Ln [fasting triglycerides (mg/dL) x fasting glucose (mg/dL)/2]. The population was grouped into quartiles based on TGI, resulting in 33 patients per group. Multinomial Logistic Regression Analysis determined the hazard risk ratio of TGI to mortality. Three models were compared using Log-rank statistics: (1) TGI alone, (2) adjusted for age and sex, (3) adjusted for age, sex, comorbidities, use of medications (anti-hypertensive drugs, hypoglycemic drugs, lipid-lowering medication, and antiplatelet drugs).

Results: A total of 332 patients presented at our institution's Emergency Room with symptoms typical of Acute Coronary Syndrome – Myocardial infarction and with positive cardiac biomarkers. However only admitted patients with fasting glucose and triglyceride determined on admission and complete medical records were included in the study reducing the subjects to 132. 

The median age of the patients was 64 years old, 53.79% were female and 46.21% were males. The median FBS of the patients was 121.35 (102.30 – 145.98) mg/dL and the median Triglyceride was 118.59 (83.19 – 156.87) mg/dL. Of 132 patients, 71.97% have hypertension and 30.30% have Diabetes mellitus. For pre-hospital medications, 24.24% were maintained on Antiplatelets, 65.15% were maintained on Antihypertensives, 18.18% were taking Lipid Lowering Drugs, and 27.27% were taking Hypoglycemic Drugs. The 1st quartile of Triglyceride-Glucose Index ranges from 0 to 8.52, the 2nd quartile ranges from above 8.52 to 8.88, the 3rd quartile ranges from above 8.88 to 9.32, and the 4th quartile ranges from above 9.32 to 11.06. The results showed that there was a significant increase in FBS and Triglyceride as the TGI quartile range increases. History of Diabetes mellitus was also significant (P=0.024) as there were more diabetes mellitus patients who belong to higher quartiles while use of Lipid Lowering Drugs (P=0.030) were higher among those patients in the 2nd quartile. The rest of the variables showed no significant interquartile differences (p>0.05).

The TGI alone (Model 1), was not significantly associated with mortality. But when adjusted for other factors (Model 2 and 3), TGI was significantly associated with all-cause mortality. Quartile 2 (TGI >8.52 - 8.88) was 90% less likely at risk of mortality (RR 0.10, 95% CI) compared to those in Quartile 4 (TGI >9.32 - 11.06). Quartile 3 (TGI >8.88 to 9.32) was 55% less likely at risk of mortality (RR 0.45, 95% CI) compared to those in Quartile 4.

Conclusion: A lower TGI was at less at risk of all-cause mortality. Even after adjusting for confounding variables, the use of Triglyceride-Glucose Index still proved a significant association to all-cause mortality, which encompasses cardiovascular mortality, suggesting that TGI may be a possible marker for risk stratification and prognosis. This may provide a framework for evidence - based treatment plans in the management of cardiovascular risk factors. Further studies may be required to establish the relevance of the Triglyceride-Glucose Index to cardiovascular diseases, identify its impact in the management of patients with ACS. Additional research may also be done to establish ethnic-specific and gender-specific cut-off values of the Triglyceride-Glucose Index for clinical utility.