Background: Diabetes mellitus is an established risk factor for coronary artery disease (CAD). In diabetic patients measurement of glycosylated hemoglobin is a way of assessing glycemic control. The major form of glycosylated hemoglobin is HbA1c which reflects the state of glycemia over last three months. Introduction: Studies conducted to assess the correlation of HbA1c with CAD in diabetic patients have shown it to be an important predictor. Association of raised HbA1c with CAD has also been observed in nondiabetic patients. The present study was undertaken to assess the association of HbA1c with CAD and the relationship between HbA1c level with the severity of CAD in diabetic as well as non-diabetic patients. Materials and Methods: The study population consisted of 240 patients, out of which 103 were diabetic and 137 were non-diabetic. A detailed history was taken from all the patients which included history of angina, hypertension, smoking and diabetes mellitus. After an informed consent, coronary angiography was performed through femoral artery. The method for estimating HbA1c was High Performance Liquid chromatography (HPLC). Results: Out of 240 patients, 179 had CAD of whom 119 (~ 66 %) had raised HbA1c (>6.07). All the 73 diabetic patients with CAD had raised HbA1c and 46 (~43%) non-diabetic patients with CAD had raised HbA1c. The mean HbA1c in all the patients increased with an increase in the number of coronary vessels involved. The mean HbA1c level in each group of CAD was higher for diabetic patients as compared to HbA1c in the non-diabetic patients. Conclusions: HbA1c level had a strong relationship with severity of CAD in both diabetic and non-diabetic patients .It was observed that in diabetic patients, there was a significant increasing trend in HbA1c with an increasing number of vessels involved.
