Fasting for a1c?

My new doctor is making me fast for my hemoglobin A1c test. There’s no other bloodwork (like a lipid panel) that requires fasting. I’ve had probably 100 a1c tests, and I’ve never had to fast for one before. I’ll ask about this when I go in to review the bloodwork, but has anyone ever had to fast for an a1c test before?

Nope, never fasted for an A1c.

No, but last time I went for mine the nurse seemed puzzled that I hadn’t been asked to fast…she also said that you’re supposed to get A1c tests done in the morning as afternoon tests aren’t accurate. No one had ever told me that before…

I have had a few too in the last 26 years …never a FAST for an A1C …please keep us posted , why new Doc says so .

I always fast before blood tests, per doctor’s orders. I don’t know if it’s specifically for the a1c or another test. All I know is that I hate skipping breakfast.


ive heard of it when the person is type 2 but not when on insulin at all. Is it the doctor or the lab tech telling you to fast? I had a lab tech tell me i was supposed to fast and i told her no and they still did it just fine.

I recently started with a new Dr. as well, and was asked to do a fasting blood test. When I asked about it at the lab, they said it wasn’t for the A1C, but for a fasting BG so the Dr. can confirm that my basal rights are set correctly through the night.

100% no, for anyone. Lipids and fasting blood sugar are the only standard tests that diabetics get done that need to be done fasting.

No fasting for the A1c.
Ask when you go in if the lab also did a fasting glucose on that blood. If they did, that particular lab may be pairing fasting glucose with the A1c. It does give him a bit of information, but nothing more than your own early am test does. And it’s not something the lab should do on its own.
You can ask if it wouldn’t be cheaper to have the A1c without the fasting glucose and maybe he’ll change his prescription for the next one

I actually got in a bit of a disagreement with the lab tech about this. I had had a sip of diet coke that morning (didn’t know they wanted me fasting), and the lab tech was insisting sugar in the diet coke would interfere with the A1c, which is ridiculous. We called the doctor’s office and they confirmed they wanted fasting. It’s silly to do it to test for basal, since you’d need to know what my bloodsugar was before I went to sleep to know if my basal is set right.

I have always fasted for an A1c. I too am not sure if it was for other tests, but I always have because the doctor says so and the nurse says so also when she calls to confirm appointment. I have noticed on the home A1c tests that it does not require fasting, so I am sure it is for my lipid panel. Don’t think I have ever had just a A1c test without the other things.

As a Diet Coke addict I am surprised that anyone would think it had sugar in it. The caffeine would have more of an affect than the aspertame. I would have fought that as well. I don’t worry about diet coke on the way to the lab. When they ask if it was fasting I just say, “Yes”, as innocently as I can.

Years ago when I had one of my first a1c’s they wanted it fasting. But it has been a long time. My latest a1c was done in the doctor’s office. No run to the lab, it was great!

I wasn’t expecting the question, so I answered honestly. I’ll be prepared with a white lie next time!

It wouldn’t make much sense to fast, an A1C is an average of your BG range in the past 3 months because it measures the amount of glucose your red blood cells have been exposed to during their ‘lifetime’ (3 months). Eating or not eating right before won’t change the amount of glycosylated hemoglobin…
Maybe they were getting it confused with another test, a lot of the other blood related diabetes tests want you to fast.

Every Endo worth their salt, like the one at my Diabetes Center would say that no insulin dependent individual should ever fast for a blood test. Wanna pass out on the freeway? You then get compared to non-fasting test ranges. I’ve had a doc say no good, but my Endo says, these look great!

Update: They wanted a fasting test for a fasting glucose. Which is stupid for a type 1. (Though it’s nice to know that their number was close to my monitor’s number.) We discussed it, and I don’t have to fast for that reason anymore.