A1C Testing
As you know, managing your diabetes is the key to staying healthy. You check your blood glucose levels at different times of the day to make sure your diabetes plan is working. These tests tell you what your blood glucose level is at that moment, which is very helpful. However, your blood glucose levels change a lot over the course of a day. Although self-testing frequently is the best way to manage your diabetes, it ALONE does not give you the whole picture.
There is another test that can tell you your average blood glucose level over the last two to three months. This laboratory test is called A1C. You may hear a few different names for it, including:
- HbA1C
- Glycohemoglobin
- A1C
What Is Hemoglobin?
Hemoglobin is a protein inside your red blood cells. It is the part of the red blood cell that carries oxygen from your lungs to the rest of your body. Hemoglobin also carries glucose, because glucose can stick to all kinds of proteins in your body. Once glucose sticks to hemoglobin, it is stuck there for the life of the red blood cell, about three or four months. The more glucose there is in your blood, the more will end up stuck to the hemoglobin.
What Does the A1C Measure?
A1C is a measure of the amount of glucose that is stuck to your hemoglobin. Your A1C reading tells you and your health care team what your average blood glucose level has been over the last two or three months. If you have lots of glucose in your blood and your average blood glucose has been high for the past few months, then your A1C will be high. You should talk to your health care team about your daily blood glucose tests AND your A1C results.
How does my A1C reading compare to my daily blood glucose levels?
This chart is an example of how blood glucose compares to A1C. The numbers in this chart are for non-pregnant adults. "Take action" depends on your own plan, and your action steps should be talked about with your health care team. Some labs use different ways to test and a have different normal range. Talk to your health care team about your results.
| A1C Reading | Average Blood Glucose Level | Your Blood Glucose Management |
|---|---|---|
| 14% | 20 mmol/L | Very poorly managed, take immediate action to lower |
| 10% | 13.3 mmol/L | Poorly managed, take action to lower |
| 9% | 11.6 mmol/L | Poorly managed, take action to lower |
| 8% | 10 mmol/L | Marginally managed, take action to lower |
| 7% | 8.3 mmol/L | Well-managed |
| 6% | 6.6 mmol/L | Very well-managed |
How Can A1C Testing Help Me?
The Canadian Diabetes Association recommends that everyone with diabetes try to achieve an A1C of less than 7%. Lower is better, that is between six–five if you can get there without having too much hypoglycemia. If your A1C is high, your health care team may change your diabetes plan to help you to better manage your blood glucose. Changes in your management plan should be expected from time to time and will help bring your A1C closer to normal.
Research shows that managing blood glucose levels well may lower your risk of major health problems including:
- Heart disease
- Stroke
- Kidney disease
- Eye disease
- Nerve damage
- Amputations
- Circulation problems
By keeping your blood glucose levels close to normal, you can stop or delay the damage high blood glucose does to blood vessels and nerves. You can prevent the complications of diabetes.
Where Do I Go for an A1C Test?
Most people will go to a medical lab for this test. A few doctors or medical clinics will be able to do the test by taking a drop of blood from a finger stick. If this is the case, you can wait for the results and talk about them with your doctor right away.
How Often Should I Have an A1C Test?
The Canadian Diabetes Association says people with diabetes should have the A1C test done every three months or up to every 6 months if their blood glucose levels are in the normal range.
How A1C Testing Helped Maria
Maria has type 2 diabetes. She was testing her blood glucose every morning before breakfast. Her blood glucose was usually normal, below 5.5 mmol/L. She was shocked when she learned her A1C was high (9%). Maria found out that her morning blood glucose was normal, but her blood glucose at other times of the day was high. She needed to manage her morning AND her after-meal and bedtime blood glucose levels.
With the help of her health care team, Maria made changes to her diabetes care plan to help her better manage her blood glucose. In fact, Maria was happy to learn that her A1C went down to 7.5% by her next visit, which showed her new plan was really working all day long.