The Association between Hemoglobin A1c and the Severity of Coronary Artery Disease in Non-diabetic Patients with Acute Coronary Syndrome

Introduction The relationship between the severity of coronary artery disease (CAD) with hemoglobin A1c (HbA1c) levels in diabetic patients is well-understood. However, the association between HbA1c and the severity of CAD in non-diabetics is still controversial. We wanted to find out if HbA1c of the non-diabetic adult population, presenting with an acute coronary syndrome (ACS), had any correlation with the severity of CAD. Methods We selected 119 non-diabetic adults who underwent coronary intervention for clinical reasons during the period of July 2015 to February 2017. The mean age of the patients was 54 ± 10.2 years. All patients were labeled as ‘acute coronary syndrome’, which included unstable angina, non-ST elevation myocardial infarction (NSTEMI), and ST-elevation myocardial infarction (STEMI). We obtained blood samples of patients for laboratory investigations, including HbA1c. We used the SYNTAX score as a tool to classify the severity of CAD, and patients having a SYNTAX score of >22 were considered to be having severe CAD. Results In order to find out the association between HbA1c and CAD, a linear regression analysis of HbA1c with the SYNTAX score was performed, which showed no statistically significant correlation between the SYNTAX score and HbA1c (correlation co-efficient = 0.142; p-value = 0.124). To compare the median value of HbA1c in groups with SYNTAX scores of ≤22 and those with SYNTAX scores of >22, we analyzed the data with the Mann-Whitney U test, which showed no significant difference in HbA1c between the two groups (p-value = 0.771). We determined the independent predictors of the severity of CAD by analyzing all variables with logistic regression, considering a SYNTAX score of >22 as a dependent variable. None of the variables, including HbA1c, proved to be statistically significant in multivariate logistic regression analysis. The unadjusted and adjusted odds ratio (OR) of HbA1c with 95% confidence intervals (CI) were 1.71 (0.47-2.92), p-value = 0.735 and 0.87 (0.33-2.29), and 0.78, respectively. Conclusion In conclusion, we find that HbA1c is not an independent predictor of the severity of CAD in non-diabetic adult patients.