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HBA1C Really High

Jayne_Eyre

Newbie
Messages
3
Type of diabetes
Type 2
I have been diabetic for 20 years, was put on metformin, then put on empaphaglozin (Jardiance) tablets which make you pee out all the sugar in your blood.

Well today I saw the nurse and she did my DB blood test, she then said my last blood test was very high 83, I said to her 'my sugar was only on 7 before lunch today how on earth can you get a reading of 83?

She said there was different tests on blood, so I asked her if it was a waste of time doing finger pricks at home and she said yes.

So, can anyone tell me what's going on here as I am very confused.
 
HbA1c measures your average blood sugar over the past three months (this is a simplification) while a fingerprick/ blood glucose monitor tells you what it is at that moment. They are measuring two very different things and don't directly relate to each other.

Testing your blood sugar via fingerpricks at home is not automatically a waste of time but you need to work out why you're testing and when otherwise the readings can be meaningless.

I test when I get up each day in order to see if it's generally going up or down, but the most important testing I do is before and two hours after a meal to see what effect that particular meal had on me, to help me decide whether that meal is going to feature often, rarely or never in my diet going forward.

Hope this was helpful - ask any more questions you may have, no-one gets it all immediately!
 
See above. The HbA1c really tells you what's going on long-term, and it smooths out all the short-term things that make your blood glucose go up and down.

Daily testing is not much use for monitoring, and your nurse is right about that, in my opinion.

What fingerprick testing will tell you is what the impact of carbs in foods are, providing you test before eating to establish a baseline, and then again two hours later. At the two hour point your insulin response should have dealt with the glucose produced as the food carbs were digested, and returned you to round about where you started.

You are not testing to see "how high you go". The high BG point is normally around 40-45 minutes or so after eating - everybody's BG will go up after eating carbs, non-diabetics included. Exactly how high depends on several things - how many carbs, how efficiently you digested them, and how efficiently your insulin response worked. Much of that is simply not in our short-term control directly.

If the +2 hr reading is more than 2mmol/l higher than the baseline, that means there was too much glucose for your systems to handle properly. Too many carbs in what you ate, therefore. You then have the information that allows you to (eg) reduce or eliminate that food or that meal from your normal diet.

Does that help?
 
Thank you both for your information, so finger prick testing is to find out what foods do to my sugar level so I can work out good and bad.

So, I just don't understand how they test my blood and it tells them whats gone on in the past 3 months?
 
Jayne_Eyre said:
Thank you both for your information, so finger prick testing is to find out what foods do to my sugar level so I can work out good and bad.

So, I just don't understand how they test my blood and it tells them whats gone on in the past 3 months?
Click to expand...
I think you mean HbA1c? That's a different test entirely.

Fingerprick testing tests the level of blood glucose in your capilliary blood at the moment of testing. It doesn't tell you what was going on 20 minutes ago or where you might be in 20 minutes time.

HbA1c doesn't measure blood glucose directly. Instead the test counts the number of glycated red blood cells - the ones that at some point have had a glucose molecule attached to their haemoglobin. Red blood cells live about three months. So from the proportion of cells, it's possible to estimate what the level of glucose was for those three months. This also means that the test is heavily skewed towards recent weeks, because many of the cells that were around three months ago have already died and been replaced.

HbA1c can be inaccurate, for example for people with anaemia, because they don't have the expected number of red blood cells. However it's currently thought to be the best test available for showing you what's going on over the short to medium term, as far as blood glucose is concerned.

You can't really read across from fingerprick testing to HbA1c, because of them measuring different things in different ways. And with fingerprick testing, you only have the snapshot - no clue as to what happens when you don't test, which is almost all of the time. You might get an indication about how well or how badly you're doing but not much more than that.

To be complete - constant glucose monitors don't test blood at all. They measure glucose in the interstitial fluid and then uses an algorithm to estimate what the blood glucose value is likely to be. Interstitial fluid generally lags blood glucose by about 15 minutes, so there can be inaccuracies in changing circumstances, for example.
 
And a little more - I've got "too many" red blood cells so have a fructosamine blood test instead
 
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