Hi, in recent months I seem to have succeeded (or so I thought) in lowering my BG levels with dietary changes. I test every morning on waking and at varied times through out the day (before/after meals etc) and have a 90 day average reading of 6.3 which according to the Diabetes uk calculator should give me a HbA1c of about 6. Calculating it with the formula: 90 day av + 2.52 / 1.583 gives a HbA1c of 5.6 yet my results have come back with an HbA1c of 6.9 which would mean my average BG would have to be about 8 - 8.5 and it is never that high. In the last 6 months I've quit smoking, lost 22lbs and thought I'd considerably lowered my bg. I feel I could cry, all the effort and then getting that result back.Could the test be wrong?
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HbA1c test results
- Thread starter jeff@jgee
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HbA1c results are not an exact science... two individuals with completely the same blood glucose control can get two different readings on an HbA1c test due to variances in blood make-up. That said I would not expect the test to vary by more than 1%.
Secondly blood glucose testing gives a snap shot at any one time and even if you test every meal you may be missing unexpected spikes... alternatively you may also be running higher sugars whilst you sleep... which can all increase an HbA1c result.
Secondly blood glucose testing gives a snap shot at any one time and even if you test every meal you may be missing unexpected spikes... alternatively you may also be running higher sugars whilst you sleep... which can all increase an HbA1c result.
borofergie
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Hiya, welcome, please don't be discouraged.
I agree with Pneu, despite the power we all invest in it, HbA1C is an imperfect measure of blood glucose control, because of differences in everyones physiology. It is best compared against your own previous results, than with anyone elses.
Also bear in mind, that something might have gone wrong the test. As you know from doing your own BG tests, every once in a while you get a wrong result. I'm sure the same thing happens with lab tests too (which is why they always have A & B samples for drugs tests on sportsmen).
Your testing regime seems sound enough. I suggest that you trust in that and don't become disheartened.
Why don't you also do a postal HbA1C test (about £20) and see what it says. I might help you get through the next 3 months.
I agree with Pneu, despite the power we all invest in it, HbA1C is an imperfect measure of blood glucose control, because of differences in everyones physiology. It is best compared against your own previous results, than with anyone elses.
Also bear in mind, that something might have gone wrong the test. As you know from doing your own BG tests, every once in a while you get a wrong result. I'm sure the same thing happens with lab tests too (which is why they always have A & B samples for drugs tests on sportsmen).
Your testing regime seems sound enough. I suggest that you trust in that and don't become disheartened.
Why don't you also do a postal HbA1C test (about £20) and see what it says. I might help you get through the next 3 months.
Hi Pneu, thanks for your input. The nature of my work means I sleep/eat at different times and always test on waking, I also test randomly between meals. In all I test about 5 times a day so I don't think it it's likely to be unexpected spikes and if that was the case they would have to be very large and frequent spikes to put my BG average up by in excess of 30% 
The variation in the conversion and the actual results are not so strange.
The two tests measure two different things and any conversion can only be approximate.
Your meter may be calibrated in whole blood or plasma, that can make a difference of about 10%.
The lab tests are pretty accurate and the doc. will always take the lab. result over any home testing.
On the positive side, your BGs are good, you are the right side of 7% and you have lost a lot of weight, that can't be bad.
Remember that diet and excercise do not work for everyone, sometimes a small amount of medication can work wonders and it makes day to day eating a bit more tolerable.
Keep up the good work.
H
The two tests measure two different things and any conversion can only be approximate.
Your meter may be calibrated in whole blood or plasma, that can make a difference of about 10%.
The lab tests are pretty accurate and the doc. will always take the lab. result over any home testing.
On the positive side, your BGs are good, you are the right side of 7% and you have lost a lot of weight, that can't be bad.
Remember that diet and excercise do not work for everyone, sometimes a small amount of medication can work wonders and it makes day to day eating a bit more tolerable.
Keep up the good work.
H
Don't be discouraged Jeff, Lab's also are 'out' sometimes, with the same sample different labs will give you different readings.
6.9% is still good, the right side of 7.
It's also an average number, if you test regularly then you know personally where your control lies. there are certain things that can cause hba1c's to be slightly altered, like anaemia and other health conditions also medications i believe and people of certain races tend to produce slightly raised hba1c's i belive i read somewhere.
What i would judge more on is your day to day BG readings, your weight loss and most of all the quitting smoking, well bloody done! i smoke and i so badly want to quit but it's just not the right time for me.
Don't judge your control fully on your hba1c, after all this is why we test daily right?
always remember to calibrate your meter often and trust it to guide you. Use the hba1c to keep your doc happy and keep doing what your doing because it sounds great to me
6.9% is still good, the right side of 7.
It's also an average number, if you test regularly then you know personally where your control lies. there are certain things that can cause hba1c's to be slightly altered, like anaemia and other health conditions also medications i believe and people of certain races tend to produce slightly raised hba1c's i belive i read somewhere.
What i would judge more on is your day to day BG readings, your weight loss and most of all the quitting smoking, well bloody done! i smoke and i so badly want to quit but it's just not the right time for me.
Don't judge your control fully on your hba1c, after all this is why we test daily right?
always remember to calibrate your meter often and trust it to guide you. Use the hba1c to keep your doc happy and keep doing what your doing because it sounds great to me
Grazer
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Have you checked your readings before bed? Some people have good readings all day, but have raised levels at bedtime. This can lead to elevated levels all night, which can ruin your averages.
I use to get this, so now eat nothing within 2 hours of going to bed, not even an apple!
I use to get this, so now eat nothing within 2 hours of going to bed, not even an apple!
Would like to thank all of you for your input and encouragement. With regards to taking readings before bed I do this occasionally and have never experienced raised levels also I quite often have to get up after 2-3 hours of sleep to work and then go back to bed a few hours later. On waking I always take a reading and again the readings are ok! I think I'm going to have to ask the doctor to do another test and see how the results turn out.
Jeff
From www.chriskresser.com/when-your-“normal”-blood-sugar-isn’t-normal-part-2
'And while A1c is a good way to measure blood sugar in large population studies, it’s not as accurate for individuals. An A1c of 5.1% maps to an average blood sugar of about 100 mg/dL. But some people’s A1c results are always a little higher than their FBG and OGTT numbers would predict, and other people’s are always a little lower.
This is probably due to the fact that several factors can influence red blood cells. Remember, A1c is a measure of how much hemoglobin in red blood cells is bonded (glycated) to glucose. Anything that affects red blood cells and hemoglobin – such as anemia, dehydration and genetic disorders – will skew A1c results.'
Peter
From www.chriskresser.com/when-your-“normal”-blood-sugar-isn’t-normal-part-2
'And while A1c is a good way to measure blood sugar in large population studies, it’s not as accurate for individuals. An A1c of 5.1% maps to an average blood sugar of about 100 mg/dL. But some people’s A1c results are always a little higher than their FBG and OGTT numbers would predict, and other people’s are always a little lower.
This is probably due to the fact that several factors can influence red blood cells. Remember, A1c is a measure of how much hemoglobin in red blood cells is bonded (glycated) to glucose. Anything that affects red blood cells and hemoglobin – such as anemia, dehydration and genetic disorders – will skew A1c results.'
Peter
