October 19, 2003
A1c (Glycohemoglobin, HgbA1c)
Question from Pennsylvania, USA:
I recently asked a question about my son’s A1c which our diabetes nurse educator was unable to answer when I asked for some sort of explanation. Because our visits seem so rushed, I honestly did not get a chance to ask our endocrinologist the same question.However, your answer was very much appreciated and so very insightful.
After I left the doctors office, I decided to order several at home A1c tests about the same time that I originally asked you the same above question and just received them. Apparently, they recently became available without a prescription. Do you agree with the package insert that indicates the following?
The insert stated something to the effect that when one performs an A1c test, it typically reflects 50% from the immediate preceding month, 25% from the month before that and 25% for the month before that. When considering the original response from you all and the insert information from the inserts, things make a little more sense as far as why my son’s blood sugars didn’t drop as much as I had expected. After reading the information, I decided to wait a few more weeks to perform the test as my son has had (to date) excellent blood sugar readings this month. It will be interesting for me to see the results, especially if he continues to have good to excellent readings for the rest of the month.
Family members came up with their own theory for why my son dropped 2% points from initial diagnosis with high blood sugars and only 0.3% three months later with excellent blood sugar readings with the exception of a few weeks. They stated that perhaps blood sugars plateau like when you are on a diet. (You lose a lot at first and then have to work harder to get the rest off.)
Do you feel that the home A1c tests will portray an accurate result? Do you have a professional opinion my family members’ theory?
Answer:
After looking at the studies provided by the manufacturer, talking to colleagues who were using the kits and then doing my own correlation studies comparing the home hemoglobin A1c kits to the hospital lab, I decided to use them in my practice. The almost immediate feedback (eight minutes) is invaluable in making on the spot clinical decisions. It makes the most sense to do the test at least two months after the last test so that you are evaluating a new time period. Sometimes, however, I might test a patient’s A1c after one month to show them how much progress they have already made since there is a 50% change in one month. This is pretty much what happened in your case. The first test was 10%. Two months later was 8.3%. Had you tested the second time at four weeks rather than 6 weeks, it probably would have been around 9%. The important thing is that the test is going in the right direction and an almost 2% drop in A1c in two months is outstanding! Keep up the good work.
JS
