Type 1 Can insulin before a fasting blood test lead to high Hba1c ?

[blacknjr]

I took a correction injection first thing in the morning because my blood sugar was high but while i was doing the blood test the nurse told me that i should never take insulin before a fasting blood test as it will lead to hyperglycemia in my results , did anyone had taken insulin before a fasting blood test? And did it affect your results?

 

[RachelK]

It shouldn’t. The HbAc1 is looking at your average BGL over the past 3 months

 

[EllieM]

I've never been asked to fast for an hba1c....However, plenty of other tests (eg fasting blood sugar and some cholesterol ones) prefer you to fast.) As a T1, no one cares about my fasting blood sugar though.

Logically, I can't see how injecting insulin would make any difference to the hba1c, but if anyone can find a good reason I'd love to hear it.

 

[Antje77]

the nurse told me that i should never take insulin before a fasting blood test as it will lead to hyperglycemia in my results

That's nonsense.
Taking insulin before a fasting blood test does not affect your hba1c, as this reflects your blood glucose over the past 3 months.

It also won't lead to hyperglycemia, she might have meant hypoglycemia.

If you're comfortable correcting when fasting, it's perfectly safe to do so.

 

[Member496333]

Seems highly dubious. Perhaps it may skew some other metrics but it’s not going to cause hyperglycaemia. Crossed wires? But even if you took too much and caused a hypo, it wouldn’t put much of a dent in HbA1c the same day. I respectfully suggest your nurse is talking absolute cobblers.

 

[JMK1954]

She sounds just like my GP practice nurse - useless for advice and talks absolute rubbish.

 

[In Response]

I wonder if there is a terminology confusion.
It is not uncommon to take a blood sugar reading first thing in the morning - people with type 2 may use this to track their progress. I have seen this referred to as a "fasting blood test". If you were to take a correction insulin dose prior to this fasting blood test, it would lower your numbers and give a force impression of what has happened to your levels overnight.
Maybe this is what the nurse was referring to?

 

[Member496333]

I wonder if there is a terminology confusion.
It is not uncommon to take a blood sugar reading first thing in the morning - people with type 2 may use this to track their progress. I have seen this referred to as a "fasting blood test". If you were to take a correction insulin dose prior to this fasting blood test, it would lower your numbers and give a force impression of what has happened to your levels overnight.
Maybe this is what the nurse was referring to?

Very possibly, but as a type 1 what difference does it make? You have to use insulin in order to survive. It’s not like you’re cheating

 

[jape]

Why on earth would an insulin injection give one a hyperglycemic incident??? Au contraire. it might be a hypo! Also, a single insulin injection has NO impact on hba1c, but it might impact one's BG reading. When I go for bloodwork, and my BG is somewhat high, I do cheat by giving me an insulin injection to lower my BG reading. That keeps the doctor happy.....

 

[Daibell]

Hi. Most diabetes blood tests now are not fasting like they used to be. The fastest glucose value is pretty meaningless and the HBA1C is a 3 month average. Occasionally you may be given a fasting lipids test to check your cholesterol ratios.

 

[JMK1954]

Well, my fasting blood tests stopped as soon as I complained to my previous GP that I was hypo on the bus on the way there. (I had never been asked for a fasting blood test between diagnosis as type1 in 1964 and some point after about 2010.)

 

[In Response]

Very possibly, but as a type 1 what difference does it make? You have to use insulin in order to survive. It’s not like you’re cheating

I never said “don’t take insulin before your first blood test”.
However, until someone with Type 1 tests their blood sugars they wouldn’t know how much insulin to dose either as a correction or as a breakfast bolus or as a pre-emotive foot on the floor bolus.
Taking insulin is not cheating but taking a fast acting insulin when you don’t know what your current blood sugar level is is dangerous.

 

[Member496333]

I never said “don’t take insulin before your first blood test”.
However, until someone with Type 1 tests their blood sugars they wouldn’t know how much insulin to dose either as a correction or as a breakfast bolus or as a pre-emotive foot on the floor bolus.
Taking insulin is not cheating but taking a fast acting insulin when you don’t know what your current blood sugar level is is dangerous.

Sure. But what I meant was that if you need to take insulin then you need to take insulin. It’s not like the nurse/doctor want to know the quality of your glucose regulation without it. Type 1s don’t produce their own, so it’s moot. I could maybe understand if the patient was type 2 or diagnosis uncertain, but even then an insulin dose is going to have no impact on a HbA1c draw that same morning. Basically I think the nurse is just talking rubbish. It wouldn’t be the first time

EDIT: I have just realised I misunderstood your original post. Apologies. All is clear now, but I don’t think that’s what the nurse meant. Not going by the wording of the OP.