Hemoglobin (Hb) A1c With eAG

Self-monitoring of blood glucose (SMBG) is one of the two primary techniques available for health providers and patients to assess the effectiveness of the management plan on glycemic control in diabetes. SMBG is typically carried out in the form of frequent fingerstick capillary glucose testing. Another more recent technology available is continuous glucose monitoring (CGM) carried out through a sensor that measures interstitial glucose concentration which correlates well with plasma glucose and capillary glucose levels. The second glycemic control technique is measurement of hemoglobin A_1c (Hb A_1c).

Because measurement of Hb A_1c is primary, the most accurate glycemic control tool available, it is important to correlate Hb A_1c results with ones obtained using SMBG for long-term metabolic control and management of diabetes. Recently, the international multicenter A_1c-Derived Average Glucose (ADAG) trial successfully completed and results determined that the correlation between Hb A_1c results and eAG (the new term used to combine both CGM and fingerstick capillary glucose testing) is strong enough to justify reporting of both an Hb A_1c results and eAG result. This conclusion is endorsed by the American Diabetes Association (ADA) and the American Association of Clinical Chemists. The relationship is expressed in the following formula:

eAG(mg/dL) = 28.7 x Hb A_1c(%) - 46.7

This relationship applies only to Hb A_1c methods certified as traceable to DCCT reference, and is based on overall averages and may vary slightly in individual patients. LabCorp uses a DCCT traceable method.