Sugar Matters
November 5, 2013
A few cautions about the A1C test…

I know for a fact that most of you reading this have an A1C drawn more often than you do a finger stick check, because from what I recall from our mission trip to St Vincent this year, many people do not have/use a home glucose checking machine. Am I right?

If this is the case, then the A1C is carrying a lot of load there in regard to information for your doctor/nurse towards making treatment decisions for you. For those of you who do not remember, the haemoglobin A1C test (called simply A1C for short) is a common test in diabetes care.{{more}} It is a blood test that tells you what the average blood sugar has been for the past three months. It is always given in percentage (for example 5 per cent is normal) and that correlates by a formula to an average number. This is how your doctor/nurse can figure out how your blood sugars have been doing by simply obtaining that A1C number. It has in fact, changed diabetes care completely. In an ideal situation, a patient would be checking his/her blood sugars daily or at least a few times a week for several times a day), AND getting a hemoglobin A1C every three months.

Now there are a few cautions about using the hemoglobin A1C, and I want to bring this up especially because in St Vincent and the Grenadines we are asking this one test to do a lot, since many people do not test at home. Keep these factors in mind:

1) The haemoglobin A1C is affected by anemia (low blood count). You can think of the A1C as a measure of how much sugar is attached to your blood cells. As a way of picturing this problem: say you have a playing field full of coconuts ready to transport. But you only have 10 pick-up trucks instead of the usual 20. You then send these 10 trucks out the gate. Someone watching this may think you only have enough coconuts for 10 trucks, while not knowing that in fact you have enough for 20 trucks, right? This is the problem with using the A1C when someone has a low blood count/anemia. So, if this is a problem for you, make sure you discuss with your doctor that your A1C may be FALSELY LOW. My patients with kidney problems, sickle cell or other causes of low blood counts all need to have other tests done instead of the A1C because I cannot rely on it to give me a true picture of what is going on.

2) The A1C gives AVERAGES, not specific patterns. This is the main problem with making changes in someone’s medications as far as I am concerned; particularly when using insulin, it can be a big issue. Hemoglobin A1C of 9 per cent is too high. But does it man that morning blood sugars are too high? After lunch? Dinnertime? All of them? There is no way to know without doing finger checks during the day because the A1C is an average of all numbers at all times.

These are my two biggest caveats with this test, and there are a few more, but I wanted to focus on these for now. That said, again I encourage you to at least get this test done if you are not able to do finger checks at home. If you can get both done, you will provide your doctor with a word of useful information to help you.

Until next week, stay safe and healthy Vincies!

Anita Ramsetty, MD [email protected]
Medical Director Endocrine Care Group
Tel: 843-798-4227