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

blacknjr

Member
Messages
19
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?
 
It shouldn’t. The HbAc1 is looking at your average BGL over the past 3 months
 
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.
 
blacknjr said:
the nurse told me that i should never take insulin before a fasting blood test as it will lead to hyperglycemia in my results
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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.
 
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.
 
She sounds just like my GP practice nurse - useless for advice and talks absolute rubbish.
 
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
 
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.....
 
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.
 
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.)
 
Jim Lahey said:
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
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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.
 
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