September 7, 2000
A1c (Glycohemoglobin, HgbA1c)
Question from Conway, Arkansas, USA:
I was diagnosed with Type 2 diabetes about 10 years ago. For the past 2 years I have had good control. The results of my most recent A1C test were strange. Though I have had low to normal fasting blood sugars, and on the day of the A1C test it was also normal, the reading was 10. It has usually been 6.3-7. Is there anything that could have thrown the reading off? I have started taking some supplements and vitamins recently, vitamin E for one. I don't have any of the usual symptoms for a high reading, such as increased urination, etc. I am going to request re-testing but wonder if I am taking something that might throw it off.
I would vote for a lab error — but one thing that can happen to the test is if your blood glucose is elevated and the lab lets the sample sit around it can “glycosylate” in the test tube and give a false high. The other thing that can happen is that samples can get mixed up. Also, make sure that they haven’t changed the method of the testing procedure and changed the normal range, although I doubt that is the problem. If on retest you are still high, investigate the accuracy of your meter and if it is okay, start testing more to see if you are running high at times you are currently not looking at.