What is Hemoglobin A1C (HbA1c)?
What is a Hemoglobin A1C?
We can’t talk about hemoglobin A1C (HbA1C) if we don’t know what Hemoglobin (Hb) is.
Hb is the major protein of red blood cells that is used to carry oxygen throughout your body
Hemoglobin sort of acts like a school bus by picking up the little oxygen students from school (your lungs) and delivering all of them safely to their homes (or the rest of your body)
If you want to know more about what hemoglobin is and what it’s used for click here.
So, now that we have a general idea of what Hemoglobin is, we can talk about HbA1C. HbA1C is a blood test that is the result from interaction between red blood cells and sugar in your blood where the sugar will actually bind to the hemoglobin:
The higher the blood glucose levels, the more glucose binds to hemoglobin, and therefore the higher the HbA1C value
So what is the actual HbA1C value? The result from the test is actually a percentage:
Hb molecules bound to glucose/total hemoglobin levels in your body and you get number like 6.2%.
So, if you have a HbA1C of 6.2%, this means that 6.2% of all your hemoglobin in your body has glucose attached to it
Why is HbA1C Used?
Practically speaking: It is your average blood sugar over the last 3 months. Now why does it measure about 3 months? Because the average lifespan of your red blood cells with the hemoglobin inside is about 3-4 months. So, the red blood cell with the sugar attached to the hemoglobin only lasts about 3 months or so before it is removed from your body.
This HBA1C value lets the health care provider get an idea of your AVERAGE blood sugars over the last 3 month period. This is more useful than a fasting glucose test because this test only represents a SINGLE POINT in time.
Another advantage is you DO NOT have to be fasting. You can get it any time of the day.
What’s the “normal value or range” of a HbA1C?
If any of you know me, you know I don’t like to use the word normal, because normal may be different for every individual. However, there are a series of number ranges that I will illustrate that constitute whether you're a non-diabetic, pre-diabetic, or a diabetic
A1c <5.7% = Non diabetic
A1c 5.7-6.4% = Pre diabetic/Border line diabetic
A1c >6.4% = Diabetic
For clarification, to call someone a diabetic using your HbA1C, it MUST be over 6.4. If not, you are technically not a diabetic.
If You Have Diabetes, How Can This HBA1C Be Helpful to YOU?
HbA1C values can be correlated to the fasting blood glucose levels you check at home
<5.7% = <117
5.7-6.4% = 117-140
>6.4% = >140
So, if you’re checking your blood glucose levels at home and you get values around 125, you can have a pretty good idea that your A1C levels fall somewhere in the range of 5.7-6.4%. This is why your health care provider will tell you to keep track of your blood sugars as you can trend the progression or regression of your diabetes.
If You Have Diabetes, What Should YOUR A1C Range Be to be Considered Optimally Controlled?
<7% = Adequately controlled
7-8.5% = Inadequate control
8.5% = Very poorly controlled
