Estimated Average Glucose eAG Calculator

How does this estimated average glucose eAG calculator work?

This is a health tool that evaluates blood glucose levels connected to the result percentage in the HbA1c testing. It allows for patients to have a target number to follow in regard to glucose level, either in mg/dL or mmol/L.

This estimated average glucose eAG calculator uses this formula eAG = (28.7 x hemoglobin A1c) - 46.7 that is based on a linear regression equation model. Given the study cited in the references, this formula is not impacted significantly by gender, age, type of diabetes or race, therefore can be used generally.

The eAG value helps clinicians set glucose level targets in patients and is especially useful in cases where the patient is not entirely compliant and in cases where the patients don’t check their blood glucose frequently enough or keep a proper track through self-monitoring of blood glucose (SMBG).

eAG and HgbA1c

It is important to clarify the relationships between hemoglobin A1c and plasma glucose levels, especially for the use of day to day patient monitoring.

HbA1c is an index of average glucose that can throw light on the preceding levels for weeks up to months because of the linkage with circulating erythrocytes with a life span of up to 4 months. However, this being a weighted proportion, the preceding 1 month values weigh more than the other 3.

This is why glycosylated hemoglobin, HbA1c can change significantly with AG and this can be shown quite fast with regular testing. The following table shows the predictable connection between the results in hemoglobin testing and estimated average glucose levels, thus helping providers set eAG goals for patients and then monitor glycemic control at certain month intervals through A1c testing.

ADA (The American Diabetes Association) just introduced the new term, eAG to help in translating the A1c results into numbers that are closer to every day readings on glucose meters.

eAG comes as a new tool in diabetes management and allows A1c further targeting, regardless of the measurement units used, either mg/dL or mmol/L and much easier to follow by patients.

As HbA1c is the best overall glucose control tool by measuring glucose molecules attached to hemoglobin, another constant connected to it, can only be as efficient. So it connects an overall status with the everyday task every patient suffering from diabetes should aim in maintaining. Then the patient only has to compare the average glucose reading from the meter with the eAG established by the health provider based on the A1c results and the therapeutic route used.

In terms of this test, the American Diabetes Association recommends at least 2 but preferably 4 A1c testings per year with results aiming under 6% (6% of hemoglobin having glucose stuck to it) which is equivalent to an eAG of 126 mg/dL or 7 mmol/L.

Blood glucose conversion table

Blood sugar levels are either measured in mg/dL or mmol/L depending on the system used, the following table presents the most common values in both measurement units as well as the conversion rules between them.

■ mg/dL x 0.0555 = mmol/L

■ mmol/L x 18,0182 = mg/dL

References

1) Nathan DM, Kuenen J, Borg R, Zheng H, Schoenfeld D, Heine RJ; A1c-Derived Average Glucose Study Group. (2008) Translating the A1C assay into estimated average glucose values. Diabetes Care; 31(8):1473-8.

2) Larsen ML, Hørder M, Mogensen EF. (1990) Effect of long-term monitoring of glycosylated hemoglobin levels in insulin-dependent diabetes mellitus. N Engl J Med; 323(15):1021-5.

3) Bunn HF, Haney DN, Gabbay KH, Gallop PM. (1975) Further identification of the nature and linkage of the carbohydrate in hemoglobin A1c. Biochem Biophys Res Commun; 67(1):103-9.

4) Koenig RJ, Peterson CM, Jones RL, Saudek C, Lehrman M, Cerami A. (1976) Correlation of glucose regulation and hemoglobin AIc in diabetes mellitus. N Engl J Med; 295(8):417-20.