Relationship between Triglyceride Glucose Index and Coronary Artery Disease in Diabetic Elderly

Cardiovascular diseases are the most important diseases of the elderly, and recently the effect of triglyceride glucose (TYG) index as one of the indicators of insulin resistance in type 2 diabetes and coronary artery disease has attracted the attention of researchers. Previous research has shown a link between insulin resistance and coronary artery calcification. Since triglyceride glucose index (TyG) is an index that is easily available, this study aimed to investigate the relationship between triglyceride index and fasting blood sugar and coronary heart disease and diabetes in the elderly of Amirkola.

This cross-sectional study was conducted on the elderly participating in the second phase of the Amirkola Health and Aging Cohort Study (AHAP). The elderly were divided into two groups of 200 people, the first group was diabetics with cardiovascular disease and the second group was diabetic elderly without cardiovascular disease. Patient information including age, sex, body mass index, diabetes, coronary artery disease, history of dyslipidemia, medications, triglycerides, fasting blood sugar, smoking habits, systolic and diastolic blood pressure, cholesterol, creatinine, physical activity, and HbA1c were collected in a checklist. The TYG index was calculated based on the LN formula [fasting triglycerides (mg/dl) × fasting glucose (mg/dl)/2]. Ultimately, SPSS version 25 software was utilized to describe the data using mean, standard deviation, and percentage. The qualitative variables were compared with the coronary artery disease using the chi-square test, while the quantitative variables were compared using the independent t-test in univariate analysis. Furthermore, the process of adjusting for confounding variables was carried out by using multivariate logistic regression.

In this study, 400 diabetic elderly participants were examined based on the relationship between triglyceride glucose index and coronary artery disease. The average age of the elderly with coronary artery disease was 70.46±6.10 and the elderly without coronary artery disease was 70.50±6.49 years. Triglyceride glucose index in diabetic elderly with and without coronary artery disease was 9.3±0.68 and 9.30±0.65, respectively, which was not statistically significant (P=0.92). Mean creatinine (P=0.004), number of comorbidities (P<0.001), and drugs consumed (P<0.001) were significantly higher in diabetic elderly with coronary artery disease. The probability of coronary artery disease in diabetic elderly with cholesterol above 200 mg/dL (OR=0.549, P=0.018) or use of antilipid drugs (OR=2.050, P=0.002) or more than three underlying diseases (356.4=OR- P=0.0001) had more. The mean cholesterol in diabetic elderly without coronary artery disease was significantly higher than that of elderly with coronary artery disease(P<0.001).

Based on the results of the study on diabetic elderly, glucose triglyceride index cannot be an independent risk factor and a suitable tool for the clinical forecast of coronary artery disease in Type 2 diabetes. Triglyceride glucose index alone cannot help in the prognosis of coronary artery disease and finally, the role of triglyceride glucose index in coronary artery diseases and various types of cardiovascular diseases needs more research.