Correlation of HbA1c value and coronary artery disease diagnosis in nondiabetic patient population

Aim: Coronary artery disease is one of the leading cause of morbidity and mortality worldwide. In terms of coronary diseases providing healthy and long life with lower costs forms the basis of preventive medicine. For this reason, biochemical markers are needed to determine the risk of coronary artery disease in protective medicine. Our study aimed to question the predictivity of HbA1c in coronary artery disease. Materials and Methods: Patients with an indication for coronary angiography who were admitted to Bezmialem Vakif University Cardiology Policlinics between January 2016 and June 2018were screened retrospectively and included. Patients with known diabetes or those with HbA1c values of 6.5 and above were excluded from the study. A total of 247 patients were included in this study. The age range is determined as 30-90. Comparative HbA1c data were obtained according to stricture groups and statistical significance was sought. For statistical analysis NCSS (Number Cruncher Statistical System) 2007 (Kaysville, Utah, USA) program was used. Student t Test, Oneway Anova Test, Bonferroni test, Kruskal Wallis test and Bonferroni-Dunn test were used to evaluate the study data. Logistic Regression Analysis (Backward Stepwise) was used to examine the risk factors affecting stenosis positivity. Pearson's chi-square test and Fisher-Freeman-Halton test were used to compare qualitative data. Significance was evaluated at p <0.05 level. Results: One hundred twenty patients with no stenosis in any coronary artery, 56 patients with only >50% stenosis in one coronary artery, and 71 patients with more than one coronary artery stenosis were enrolled in the study. There was a statistically significant difference between the HbA1c measurements according to the degree of stenosis (p = 0.001; p <0.01). As a result of the paired comparisons to determine which group has the meaningful difference; the HbA1c measurements of the multipl stenosis group were more than the groups of less than 50% (p=0.001) and single >50% stenosis (p = 0.001)(p <0.01). Stenosis (+) ratio was found to be significantly higher in patients with HbA1c level 5.7-6,5 than HbA1c level <5.69 (p = 0.001; p <0.01). The fact that 5.7-6.5 HbA1c level increases the risk of stenosis to 6.260 fold. The ODDS ratio for HbA1c was 6,260 (95% CI: 3,160-12,401). The cut off point for HbA1c was found to be 5.6 and above according to stenosis positivity. In the regression analysis, HbA1c was an independent risk factor for coronary artery disease. One-unit increase in HbA1c measurements increases the risk of being stenosis positive to 12,424 times (95% CI: 5,990-25,767). Conclusion: In this retrospective observational study, we showed that HbA1c can be used as an independent marker in identifying coronary artery disease and it is indicating the severity of the disease in non-diabetic individuals. This result may give us an insight in preventive medicine in terms of which patients are at risk or need to be taken into protective health procedures. Key words: Nondiabetic, HbA1c, coronary artery disease