A1c Is A Predictor of Coronary Disease Even Without Diabetes

An A1c over 4.6% increases your risk for coronary disease.

Chronic hyperglycemia has long been a suspected culprit in the development of coronary heart disease (CHD). As a marker of long-term glycemic control, glycated hemoglobin (A1C) is a useful and reliable risk indicator for developing CHD, even in people without diabetes whose A1C levels are in the high normal range, according to a study published in the September 12 issue of Archives of Internal Medicine.

The researchers conducted a prospective study of 1,321 adults without diabetes and a cohort of 1,626 adults with diabetes in the Atherosclerosis Risk in Communities Study. CHD and other outcomes were tallied for an 8- to 10-year follow-up period.

Overall, researchers found that those with diabetes who had the highest A1C levels were more than twice as likely to develop CHD than those with the lowest A1C levels.

Among subjects without diabetes, those with the highest levels of A1C were about 1.5 times more likely to develop CHD than nondiabetic patients with the lowest levels. No greater risk of CHD was noted at A1C levels 4.6% in this group, while risk of CHD increased significantly when A1C levels were 4.6%. Each 1% increase in A1C over 4.6% raised the risk of CHD nearly 2.5 times, according to researchers.

Selvin E, Coresh J, Golden SH, et al.: Glycemic control and coronary heart disease risk in persons with and without diabetes: The Atherosclerosis Risk in Communities Study. Arch Intern Med 16:1910–1916, 2005.