As a pharmacist, you will see a push to use eAG, estimated average glucose, a calculated conversion of A1c. The American Diabetes Association and others will encourage health professionals, labs, and device manufacturers to speak in terms of eAG.
The idea is to make results more meaningful for patients. "Average" glucose is easier for patients to understand. It's in mg/dL, the same units as their home blood glucose tests. Some clinicians are already doing this, but there have been questions about the most accurate way to convert A1c to eAG. The old way used an A1c of 6% to equal 135 mg/dL, then adjusted it up or down by 35 mg/dL for every 1% change in A1c.
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Now we have a more accurate equation: eAG = 28.7 × A1c - 46.7...
For an approximation, use this table...
Use eAG, estimated average glucose, a calculated conversion of A1c..
equation: eAG = 28.7 × A1c - 46.7...
Expect labs to eventually report both A1c and eAG. Tell patients to think of a single blood glucose as a "snapshot" of glucose control at one moment and that it varies depending on food, exercise, stress, etc.
Explain that eAG is a running average over 3 months of ALL glucose fluctuations, NOT just an average of numbers they get when they test. This means we can now tell patients to aim for an estimated average glucose less than 154 mg/dL instead of an A1c below 7%. Keep in mind that eAG's purpose is to help patients correlate a number to their A1c. Continue using A1c values when adjusting therapy since they have the most evidence.
REFERENCES
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Ram N, Ahmed S, Sattar S, Furqan S, Islam N. Relationship Between Estimated Average Glucose (eAG) and Fasting Plasma Glucose in a Cohort of Pakistani Diabetic Subjects. Cureus. 2021 Oct 2;13(10):e18435. Available at: https://www.cureus.com/articles/69691-relationship-between-estimated-average-glucose-eag-and-fasting-plasma-glucose-in-a-cohort-of-pakistani-diabetic-subjects
Kahn R, Fonseca V. Translating the A1C Assay. Diabetes Care. 2008 Aug;31(8):1704-7. Available at: https://diabetesjournals.org/care/article/31/8/1704/28567/Translating-the-A1C-Assay
Consensus Committee. Consensus statement on the worldwide standardization of the hemoglobin A1C measurement: the American Diabetes Association, European Association for the Study of Diabetes, International Federation of Clinical Chemistry and Laboratory Medicine, and the International Diabetes Federation. Diabetes Care. 2007 Sep;30(9):2399-400. Available at: https://diabetesjournals.org/care/article/30/9/2399/29316/Consensus-Statement-on-the-Worldwide