Study: A1C test not a reliable predictor of heart disease

CHICAGO — In a study that included nearly 300,000 adults without a known history of diabetes or cardiovascular disease, adding information about glycated hemoglobin (HbA1c), a measure of longer-term blood sugar control, to conventional CVD risk factors like smoking and cholesterol was associated with little improvement in the prediction of CVD risk, according to a study in the March 26 issue of JAMA.

Because higher glucose levels have been associated with higher CVD incidence, it has been proposed that information on blood sugar control might improve doctors’ ability to predict who will develop CVD, according to background information in the article. 

Among the primary findings of the researchers, adding information on levels of HbA1c to conventional CVD risk factors was associated with only slight improvement in risk discrimination (how well a statistical model can separate individuals who do and do not go on to develop CVD). In addition, they found that adding information on HbA1c did not improve the accuracy of probability predictors for patients with and without CVD.