What is the A1c test?
The A1c test (also known as HbA1c, glycated hemoglobin or glycosylated hemoglobin) is a good general measure of diabetes care. While conventional home glucose monitoring measures a person’s blood sugar at a given moment, the A1c number reflects your average blood glucose level over the last three months.
Understanding A1c Numbers
For a person without diabetes, a typical A1c level is about 5%.
For someone with diabetes, experts disagree somewhat on what the A1c target should be.
The American Diabetes Association (ADA) recommends an A1c target of less than or equal to 7%.
The American Association of Clinical Endocrinologists recommends a level of 6.5% or below.
The National Institutes of Health (NIH) says that, in general, every percentage point drop in an A1C blood test results (e.g., from 8% to 7%) reduces the risk of eye, kidney and nerve disease by 40%.
The chart below shows what the A1c means in terms of average blood glucose levels:
| A1c |
Average blood glucose |
| 5 |
95.5 |
| 6 |
125 |
| 6.5 |
139.75 |
| 7 |
154.5 |
| 8 |
184 |
| 9 |
213.5 |
How the A1c Test Works
Hemoglobin A, a protein found inside red blood cells, carries oxygen throughout the body. When there is glucose in the bloodstream, it can actually stick (glycate) to the hemoglobin A protein. More glucose in the blood means that more glucose sticks to hemoglobin, and a higher percent of hemoglobin proteins become glycated.
Once glucose sticks to a hemoglobin protein, it typically remains for the lifespan of the hemoglobin A protein — as long as 120 days. Therefore, at any moment, the glucose attached to the hemoglobin A protein reflects the level of the blood sugar over the last two to three months.
The A1c test measures how much glucose is actually stuck to hemoglobin A, or more specifically, what percent of hemoglobin proteins are glycated. Thus, having a 7% A1c means that 7% of the hemoglobin proteins are glycated.
A person’s A1c level will not change significantly over the course of a few days, but it will shift in response to a change in overall glucose control. It is estimated that the past month will account for about 50% of an A1c value, so that value can change within just a few weeks.
How Often Is an A1c Test Necessary?
People with diabetes should have their A1c tested every three months; if blood sugars are fairly stable at near-normal levels, twice a year may be enough. Health care providers should tell patients what is right for them and enable them to monitor their diabetes management more easily. More frequent A1c tests may be recommended if someone has recently changed his or her treatment plan.
How Is the A1c Test Done?
A very simple process. One just needs to shed a drop of blood and the laboratory will take care of the rest. No don’t bother about fasting or full stomach because it doesn’t matter
What Are the Limitations of the A1c Test?
A1c results can be misleading when red blood cell survival is prolonged or reduced or in cases of anemia or hemolysis
What is the A1c test?
The A1c test (also known as HbA1c, glycated hemoglobin or glycosylated hemoglobin) is a good general measure of diabetes care. While conventional home glucose monitoring measures a person’s blood sugar at a given moment, the A1c number reflects your average blood glucose level over the last three months.
Understanding A1c Numbers
For a person without diabetes, a typical A1c level is about 5%.
For someone with diabetes, experts disagree somewhat on what the A1c target should be.
The American Diabetes Association (ADA) recommends an A1c target of less than or equal to 7%.
The American Association of Clinical Endocrinologists recommends a level of 6.5% or below.
The National Institutes of Health (NIH) says that, in general, every percentage point drop in an A1C blood test results (e.g., from 8% to 7%) reduces the risk of eye, kidney and nerve disease by 40%.
The chart below shows what the A1c means in terms of average blood glucose levels:
|
A1c
|
Average blood glucose
|
|
5
|
95.5
|
|
6
|
125
|
|
6.5
|
139.75
|
|
7
|
154.5
|
|
8
|
184
|
|
9
|
213.5
|
How the A1c Test Works
Hemoglobin A, a protein found inside red blood cells, carries oxygen throughout the body. When there is glucose in the bloodstream, it can actually stick (glycate) to the hemoglobin A protein. More glucose in the blood means that more glucose sticks to hemoglobin, and a higher percent of hemoglobin proteins become glycated.
Once glucose sticks to a hemoglobin protein, it typically remains for the lifespan of the hemoglobin A protein — as long as 120 days. Therefore, at any moment, the glucose attached to the hemoglobin A protein reflects the level of the blood sugar over the last two to three months.
The A1c test measures how much glucose is actually stuck to hemoglobin A, or more specifically, what percent of hemoglobin proteins are glycated. Thus, having a 7% A1c means that 7% of the hemoglobin proteins are glycated.
A person’s A1c level will not change significantly over the course of a few days, but it will shift in response to a change in overall glucose control. It is estimated that the past month will account for about 50% of an A1c value, so that value can change within just a few weeks.
How Often Is an A1c Test Necessary?
People with diabetes should have their A1c tested every three months; if blood sugars are fairly stable at near-normal levels, twice a year may be enough. Health care providers should tell patients what is right for them and enable them to monitor their diabetes management more easily. More frequent A1c tests may be recommended if someone has recently changed his or her treatment plan.
How Is the A1c Test Done?
A very simple process. One just needs to shed a drop of blood and the laboratory will take care of the rest. No don’t bother about fasting or full stomach because it doesn’t matter
What Are the Limitations of the A1c Test?
A1c results can be misleading when red blood cell survival is prolonged or reduced or in cases of anemia or hemolysis
