Metabolic health
Estimated average glucose (eAG)
eAG
Included in every MyHealthspan membership: Focus, Baseline, and Complete.
Compare membershipsYour HbA1c, translated into glucose meter units.
Estimated average glucose (eAG) is calculated from your HbA1c result. It expresses your average blood sugar over the past two to three months in mmol/L, the same units used by glucose meters and fasting glucose tests.
A large study linked HbA1c with average glucose.
In the ADAG study, researchers repeatedly measured glucose in people with and without diabetes over three months, using continuous monitors and fingerstick tests. They compared those averages with HbA1c and found a close, straight-line relationship, which gives the formula used for eAG.
It's still an estimate. People with the same HbA1c can have somewhat different true averages. Conditions that change how long red blood cells live, such as some anemias, can also shift HbA1c and eAG with it.
eAG puts your HbA1c in the same units as a glucose meter.
Questions
Why doesn't my eAG match my glucose meter average?
A meter average reflects only the moments you happened to test, while eAG reflects your HbA1c over about three months. eAG also varies somewhat from person to person. If the two differ a lot, it's worth discussing with a clinician.
What can make eAG less accurate?
Anything that affects HbA1c affects eAG too. Iron deficiency, some anemias, inherited hemoglobin variants, recent blood loss or transfusion, and kidney or liver disease can all shift it. The original study also didn't include children or pregnant people.
Do Canadian guidelines use eAG?
Diabetes Canada's guidelines use HbA1c and glucose tests for diagnosis and for glycemic targets, and eAG isn't one of their criteria. Its main value is helping you relate HbA1c to everyday glucose readings.