1. Glycated Hemoglobin Levels (A1C)
A1C and Risk of Diabetes
11,092 men and women free of diabetes at start of study.
Risk of Developing Diabetes (RR)
A recent study reported in the New England Journal of Medicine looked at A1C blood test results in a large population of 11 thousand people. After several years of follow-up researchers evaluated A1C as a predictor of who developed diabetes, coronary heart disease, or died from any cause. They found A1C to be as good as fasting glucose levels in predicting risk of developing diabetes, and A1C was a better predictor than glucose levels for heart disease risk and death from any cause.
This chart shows the risk of developing diabetes in a large population free from diabetes at the start of the study. As A1C levels go up, so does the risk of developing diabetes over the period of the study. Notice that the risk for diabetes climbs quickly when the A1C levels get to 6.0% and above. An A1C of 6.5% or higher indicates diabetes. This chart uses 5-5.4% as the “normal” for comparison purposes.
The researchers summarized their study by saying, “These data add to the evidence supporting the use of glycated hemoglobin as a diagnostic test for diabetes.”
Reference: E. Selvin, et al. Glycated hemoglobin, diabetes, and cardiovascular risk in non-diabetic adults, New England Journal of Medicine Mar 4;362:
Glycated Hemoglobin Levels (A1C)
New England Journal of Medicine Mar 4;362:

2. A1C & Risk of Coronary Heart Disease
11,092 men and women free of heart disease at start of study.
Risk of Developing CHD (RR)
This chart shows the risk of developing coronary heart disease (CHD) in a large population free from heart disease at the start of the study. As A1C levels go up, so does the risk of developing heart disease over the period of the study. Notice that the risk for heart disease climbs quickly when the A1C levels get to 6.0% and above. An A1C of 6.5% or higher indicates diabetes. This chart uses 5-5.4% as the “normal” for comparison purposes.
Researchers evaluated A1C as a predictor of who developed diabetes, coronary heart disease, or died from any cause. They found A1C to be as good as fasting glucose levels in predicting risk of developing diabetes, and A1C was a better predictor than glucose levels for heart disease risk and death from any cause.
Reference: E. Selvin, et al. Glycated hemoglobin, diabetes, and cardiovascular risk in nondiabetic adults, New England Journal of Medicine 362: , March 4, 2010.
Glycated Hemoglobin Levels (A1C)
New England Journal of Medicine Mar 4;362: