The laboratory diagnosis of diabetes mellitus is traditionally established by measurements of fasting blood glucose, random blood glucose with associated symptoms, and through the oral glucose tolerance test. A single measurement of glycated hemoglobin (A1C) eliminates practical difficulties of the above-mentioned methods. The optimal cut-off values of A1C for the screening of diabetic patients in the context of acute coronary syndrome are being investigated. The aim of this study was to establish a cut-off value for A1C in order to more accurately identify diabetic patients in a group of patients admitted for acute coronary syndrome.
A prospective study was conducted with 149 patients consecutively admitted for acute coronary syndrome. The diagnosis of diabetes mellitus was established based on a history of the disease or through serial measurements of fasting blood glucose levels on admission and the patients were grouped into diabetic and nondiabetic. A1C values of the two groups were statistically compared to define the optimal cut-off value.
Fifty-five (36.91%) patients were diabetic, whereas 94 (63.09%) constituted the nondiabetic group. The cut-off value for A1C with the greatest accuracy to distinguish between the two groups was 6.7%, with sensitivity of 85.45%, specificity of 91.89%, and 88.04% diagnostic accuracy.
The value of 6.7% for A1C showed good accuracy for the diagnosis of diabetes mellitus in acute coronary syndrome.