hba1c does not match glucometer

sud5nala

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Totally annoyed now.. Does that mean I might not be T2 after all? (Im anemic)

he said I was diabetic, prescribed metformin & basically sent away.. (not taking the metformin) I was 8.0.. With cutting carbs & hitting the veggie's (more iron) my meter tests have gone down. 5 on waking today, 5.4 before lunch & 5-2 two hours after.. & thats in 6 days..

Wow, in 6 days.

Congratulations for holding off on the metformin!

I was once told, "you have diabetes" by a nurse on the basis of my A1c. I googled furiously and realized that I was nondiabetic by a heap of test results, except for that one. Recent medical distress had suspiciously coincided with the leap in A1c. When I complained to the clinic management, they advised that the nurse had made no official notation that I was diabetic, despite what she had said so to my face. Weird, but to my benefit!

Home testing is useful for monitoring. It is not administratively valid for diagnosis. Since your latest numbers are trending so well, in your shoes I'd keep up the regimen for a few weeks, keep monitoring, and if there's a need, get retested. I wouldn't get retested right away, while the metabolism is in flux from the anemia treatment. If the retest is negative, I imagine they'll be only too happy to send you on your way. There's a diabetes epidemic. One less patient to treat should please them.
 
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sud5nala

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I get iron infusions as I have iron malabsorption. I had an iron infusion at the end of last year

I only get a test every 6 months or so. But if my iron level is high my guess by what you're saying is it may affect my hbA1c too?
I just had that done and find out the result next week.

My goodness, you will have to ask them if they have taken the step changes (speaking mathematically) in iron into consideration when conducting A1c tests. If you had the opposite condition -- haemochromatosis -- the A1c couldn't be used. Haemochromatosis is an excess of iron, and a major treatment is to drain blood periodically. Doing that of course spoils the preconditions for doing the A1c. I guess they infuse you with just iron, not plasma or whole blood, yes?

HbA1c is a subtype of haemoglobin. The assay for glycated HbA1c actually measures how much of the HbA1c in one's blood has chemically bonded to glucose. 5% is a good value, 6.5% is officially diabetic. The test was perfected and the diagnostic values were selected based on the physiology of normal people. You could search the Web about this. ... iron deficiency hba1c validity. ... iron deficiency/malabsorption alternate glucose assay. I have done so and here's one hit. (Johns Hopkins is the name of an elite university that has a medical school and a diabetes centre.)
 

tim2000s

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@sud5nala please stop pretending that you are a medical specialist. Most European meters apply the same calibration to give a plasma equivalent reading but use whole blood to do this as US meters. The manufacturers don't set them up differently for the US and Europe. If you read the European manuals you'd find this out.


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AndBreathe

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My finger prick testing, Libre and HbA1c scores are never matched or even particularly closely aligned, but as it has been consistently and persistently so, I've stopped trying to prove the un-provable.

I figure each time I measure blood; whether by pricking my finger and applying a droplet to a stick, wearing a sensor (measuring interstitial fluid, and mathematically converted, by application of an algorithm) or having venous blood drawn for the lab, each of those could be out by the various regulatory tolerances. There's no way I can prove if the 4.3 I had after lunch on x date was correct, 3 months on, so why sweat it?

Provided, on a day to day basis, my finger prick tests are running between what I now understand as my running range, the HbA1c at the end of the period will be around my usual numbers.

My Libre suggests I should be displaying an ultra low Hba1c, my finger prick tests still very low, but higher than the Libre, and the venous blood lab results are higher than both.

I can, and do, live with that. Not everything is under our control.
 
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Brunneria

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Totally annoyed now.. Does that mean I might not be T2 after all? (Im anemic)
I have regular blood tests (ongoing condition) & not once was diabetes mentioned. Had a test Tuesday, results Thursday.
1st thing he said was I really low in iron. Prescribed Folic acid. Then he said I was diabetic, prescribed metformin & basically sent away.. (not taking the metformin) I was 8.0.. With cutting carbs & hitting the veggie's (more iron) my meter tests have gone down. 5 on waking today, 5.4 before lunch & 5-2 two hours after.. & thats in 6 days..Will be interesting to see what the morning readings is.

Some types of anaemia make the HbA1c test less accurate.
- doesn't mean you are non-diabetic, it just means that other tests will be necessary to give a better picture.

Diabetes can be diagnosed on repeated high fasting blood glucose, on random high blood glucose tests at any time of day, and the alternative to the HbA1c (rarely used, but appropriate where HbA1c accuracy is in question) is to test Fructosamine levels.

http://www.diabetes.co.uk/news/2015...ted-through-hba1c-due-to-anemia-97409751.html

http://www.ngsp.org/factors.asp
 

Mep

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I guess they infuse you with just iron, not plasma or whole blood, yes?

Yes, just iron is infused and not plasma or whole blood. The haematologist that did my last infusion told me he needed to give me the max dosage of iron as all round my iron levels both in liver and blood were too low. But I drop iron quickly too so I'm probably within range by now I'd say as the last test was in January from memory where I was 368 level. If I'm below 300 then technically I don't have too much iron as the range is 30-300 on the lab testing here.

I'll look into the effect on hbA1c further.

Thanks :)
 

oopsie

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Wow, in 6 days.

Congratulations for holding off on the metformin!

I was once told, "you have diabetes" by a nurse on the basis of my A1c. I googled furiously and realized that I was nondiabetic by a heap of test results, except for that one. Recent medical distress had suspiciously coincided with the leap in A1c. When I complained to the clinic management, they advised that the nurse had made no official notation that I was diabetic, despite what she had said so to my face. Weird, but to my benefit!

Home testing is useful for monitoring. It is not administratively valid for diagnosis. Since your latest numbers are trending so well, in your shoes I'd keep up the regimen for a few weeks, keep monitoring, and if there's a need, get retested. I wouldn't get retested right away, while the metabolism is in flux from the anemia treatment. If the retest is negative, I imagine they'll be only too happy to send you on your way. There's a diabetes epidemic. One less patient to treat should please them.

Thanks sud5nala. I will keep on doing what I'm doing, I know I can't retest at the moment (they say cells can last up to 3months) so the old cells would be tested as well. Its so frustrating though & gave me added stress & a few sleepless nights. 4.7 on waking.
 

phoenix

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Re plasma/ whole blood readings, I think it should be a non issue now.
I wrote this in 2009
"In the UK, the manufacturers have been changing over the years and now according to DUK they all use plasma except for
those made by one of the largest manufacturers Roche ie Accu-chek meters. DUK says that ‘ Roche is in the process of adjusting their meters to give results as plasma values, which they hope will be completed before the end of 2009.’ So if you have an Accu chek in the UK read the strips leaflet carefully."
( Accu-chek changed the strip not the meter)
https://www.accu-chek.co.uk/gb/news/14april10.html
 
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drakman

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I think you can rely on your HbA1C figures as they are based on how protein stores and uses sugar, your meter measures free floating sugar which is a bit different, also it does vary a lot over quite short periods of time, this is due to how you use the sugar as fuel, also it depends on how you dgest food, which varies with different food.
Fatty foods like chocolate are also high sugar and cause pretty wild spikes as some of the sugar is bound to fat which is broken down much slower than the unbound sugar but releases quite suddenlycausing big spikes. slow release such as whole fruit of cereal are much better as they are slow continuous release sugars, this is why you get the variations even between the time to test with 2 different meters
 
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Luca2016

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Your average readings on your meter are not reliable enough to estimate an HbA1c unless you do finger prick tests every half an hour 24/7. You have no idea what is going on in between your tests.

As you say you have iron deficiency anaemia and other conditions these will no doubt have skewed your HbA1c. It is well known and proved that anaemic issues give false HbA1c results.

It is also important to remember that lab tests are done from venous blood and it is the plasma that is checked. Finger prick tests are capillary blood and it is whole blood, not plasma. Whole blood contains more glucose than plasma blood. Unless your particular meter has an inbuilt calibration to convert the whole blood reading to a plasma reading, there will, on average, be a 12% difference. The meter will read higher than the lab test by around 12%. If your meter is a Codefree or an Accu Chek Mobile, these meters are calibrated so no need to deduct/add 12%. I have no idea if others are.
I just checked what my meter measures and it is plasma in whole blood. I've had my meter for 3 and a half years. Do you know if they wear out?
 

Bluetit1802

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I just checked what my meter measures and it is plasma in whole blood. I've had my meter for 3 and a half years. Do you know if they wear out?

They can do. My first one only lasted 9 months but it was clear it wasn't working properly even after inserting a new battery. There were very haphazard readings (double figures when I was about 5 and more often than not no readings at all, just errors, or not accepting the strips.). My second meter has, up to now, lasted 12 months and is fine. My spare meter, which isn't used very often these days, still works fine after 2 and a half years.
 

Luca2016

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They can do. My first one only lasted 9 months but it was clear it wasn't working properly even after inserting a new battery. There were very haphazard readings (double figures when I was about 5 and more often than not no readings at all, just errors, or not accepting the strips.). My second meter has, up to now, lasted 12 months and is fine. My spare meter, which isn't used very often these days, still works fine after 2 and a half years.
Thanks. Yeah I've had some weird random readings like once it was 1.8 and had a fasting of 7.5 the other day which freaked me out until I checked 3 more times and it's been showing errors and turn in itself off and stuff.
 

Bluetit1802

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Thanks. Yeah I've had some weird random readings like once it was 1.8 and had a fasting of 7.5 the other day which freaked me out until I checked 3 more times and it's been showing errors and turn in itself off and stuff.

Sounds like it may be coming to the end of its useful life. Is it the same with a new battery?
 

Luca2016

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I think you can rely on your HbA1C figures as they are based on how protein stores and uses sugar, your meter measures free floating sugar which is a bit different, also it does vary a lot over quite short periods of time, this is due to how you use the sugar as fuel, also it depends on how you dgest food, which varies with different food.
Fatty foods like chocolate are also high sugar and cause pretty wild spikes as some of the sugar is bound to fat which is broken down much slower than the unbound sugar but releases quite suddenlycausing big spikes. slow release such as whole fruit of cereal are much better as they are slow continuous release sugars, this is why you get the variations even between the time to test with 2 different meters
Assuming that my hba1c is accurate would prove how the previous couple of weeks prior to the test have a lot of bearing on your hba1c result because for the 2 weeks before the test for some unknown reason my bsls were really normal whereas for the couple of months before that they were not, they ranged from about 6-7 for most of the day.
 

Brunneria

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Fatty foods like chocolate are also high sugar and cause pretty wild spikes as some of the sugar is bound to fat which is broken down much slower than the unbound sugar but releases quite suddenlycausing big spikes. slow release such as whole fruit of cereal are much better as they are slow continuous release sugars, this is why you get the variations even between the time to test with 2 different meters

This is where testing is soooooo important, because self testing has proven that most of what you say above is not true for me.

Chocolate doesn't spike me (especially good quality, dark, high cocoa solids choc)
Fruit and cereal both spike me worse than potato or even the same g of carbs from table sugar.
Whole grains release their carb load only about 5 mins after non whole grains, so I have to avoid even 'brown carbs'
I can however tolerate a small portion of berries, if they are eaten with cream.

So, while I happily accept that if you test those theories on yourself @drakman that you have found they hold true for you.
They do not hold true for me.

- which is why we should all be testing, to find out how things work for each of us.
HbA1cs simply don't give us enough detail
 

Luca2016

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Type of diabetes
Prediabetes
This is where testing is soooooo important, because self testing has proven that most of what you say above is not true for me.

Chocolate doesn't spike me (especially good quality, dark, high cocoa solids choc)
Fruit and cereal both spike me worse than potato or even the same g of carbs from table sugar.
Whole grains release their carb load only about 5 mins after non whole grains, so I have to avoid even 'brown carbs'
I can however tolerate a small portion of berries, if they are eaten with cream.

So, while I happily accept that if you test those theories on yourself @drakman that you have found they hold true for you.
They do not hold true for me.

- which is why we should all be testing, to find out how things work for each of us.
HbA1cs simply don't give us enough detail
Very true. I can eat chocolate too but forget about potatoes or cereal. Although I can have small amounts of potatoe chips.