A1C Blood Test & Estimated Average Glucose Readings

If you have diabetes, then you probably check your blood sugar levels several times a day using an at-home meter. These daily blood sugar readings are important, because they give you a good idea of your blood sugar levels at any given moment. Another important number for you to know is your A1C level, which is a measure of your average blood sugar over the past two or three months. Your A1C level should be checked by your doctor about twice a year.

How does A1C compare to Estimated Average Glucose?

The A1C level is expressed as a percentage, and it is a measure of your average blood sugar over the past two or three months. This number can be converted to an estimated average glucose, or eAG, and your eAG can be compared to your daily blood sugar readings from your at-home glucose meter. The following chart provides an easy conversion from A1C to eAG. The American Diabetes Association recommends an A1C of less than 7% (an eAG lower than 154 mg/dL) for most people with diabetes.

Why are my daily blood sugar readings and eAG levels different?

A lot of people tend to take more blood sugar readings in the morning or at other times when blood sugar levels are low, such as before meals. This may cause the average of your home glucose readings to be lower than your actual estimated average glucose. If you add testing after meals, you may get a better picture of your actual average glucose readings, and you may notice that your blood sugar is not quite as well controlled as you previously believed.

In order to have an accurate picture of your blood sugar levels, it is important to monitor both your A1C chart numbers as well as your home glucose test levels. The ADA recommends keeping A1C below 7%. If your numbers do not fall into this category, talk to your doctor about how to better control your blood sugar.