Translating the HbA_1c value into Estimated Average Glucose (eAG)

Objective: The HbA1c (A1c assay, expressed as the percent (%) of hemoglobin that is glycated (bound to hemoglobin) measures chronic glycemia and is widely used to judge the efficacy of diabetes treatment and therapy adjustment. While day-to-day management is guided by self-monitoring of blood glucose (capillary) concentrations (measured in mg/dl or mmol/l).

Results: Linear regression analysis between HbA1c (A1c) and average glucose (AG) values provided the tightest correlation (AG _mg/dl = 28.7 X A_{1c -} 46.7, R ² = 0.84 P < 0.0001), allowing calculation of an estimated average glucose (eAG) for A1c values. The linear regression analysis did not differ significantly across subgroups based on age, sex, diabetes type, race/ethnicity, or smoking status.

Conclusion: A1c levels can be expressed as eAG for most patients with Type 1 and Type 2 diabetes.

Converting HbA1c to

Estimated Average Glucose

Based on the results of the A1c - Derived Daily Glucose (ADAG) study. +

eAG results should be interpreted and target levels set by a healthcare professional. The American Diabetes Association (ADA) recommends maintaining A1c levels below 7.0%.

To perform a A1c to eAG conversion, click on the following link: http://professional.diabetes.org/glucosecalculator.aspx

To view a Power Point presentation on the eAG, click the link:  http://professional.diabetes.org/Content/eAGPowerpointSlides.ppt

Links: http://www.aacc.org/publications/cln/2008/october/Pages/cover1_1008.aspx

http://professional.diabetes.org/glucosecalculator.aspx