HbA1c represents a 4 week average?
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Klangley
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This is a really interesting thread. As you can see below my last HbA1c came out as 56 or approximately 9 mmol/L. Yet my average for the 4 weeks prior to that was 7.8 mmol/L. So either my meter is under-reading (a horrible thought) or the period it is measuring is much longer.....perhaps closer to the 2 - 3 months they suggest. I guess though I will know on my next HbA1c. The good old NHS will make me wait 3 months for that.....does anyone know if you can easily get the test done privately?
Only 3 months? I wonder why every organisation which has anything to do with the care of diabetics still tells us that the HbA1c reflects the previous 8 - 12 weeks? The HbA1c blood test measures the amount of sugar that is attached to the haemoglobin in red blood cells. and as red blood cells live about four months, it would seem logical that the HbA1c test shows the average blood sugar for the past few months (8 - 12 weeks).
As for private blood tests, my friend Google tells me that https://www.medichecks.com/find-a-test/test/HbA1c_GHB/ have an offer on at the moment, £49 instead of £99. I guess if it costs anything like £50 each time the NHS give an HbA1c, it's why they don't do them more often.
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There is little research, but as stated here: http://care.diabetesjournals.org/content/27/4/1013.full it is believed that elevated blood glucose reduces red blood cell life. This paper (the result only I'm afraid) believes that the variance in red blood cell lifespan dramatically affects Hba1C enough to affect clinical recommendations: http://professional.diabetes.org/Abstracts_Display.aspx?TYP=1&CID=54055.
In short, the answer is neither clear nor abundantly researched.
On the cost, when going to the diabetic clinic now, they take a tiny sample of blood from a finger prick. It almost certainly doesn't cost £50 a pop.
Interesting, where is your clinic, seems like us oiks in the home counties are somewhat behind the times. Are you referring to Point of Care Testing that I've been reading about? You might be surprised at what the NHS say about cost but don't take my word for it.
There is limited evidence indicating that POCT for HbA1c will result in an economic benefit [28]. DCCT and UKPDS trials established that there is an economic benefit from tight glycaemic control with long-term health benefits even though there are
short term cost increases [5, 7].
Although POCT monitoring of HbA1c is more costly than laboratory measurement, savings could be achieved in long-term healthcare due to better control of HbA1c levels and the number of clinic visits can be substantially reduced [31-33].
I'd supply the URL, but clicking on the Google entry takes you straight to the PDF. However, this might be the link. https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CB8QFjAAahUKEwilmOXUsojJAhVCxhoKHXPaBqE&url=http://www.healthcheck.nhs.uk/document.php?o=12&usg=AFQjCNH8NAG5kNFzBDEjtuO1SzvtcCS3DQ&sig2=tD3fND781PKlM737buuoDg&cad=rja
It is, just tried it.
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Except that that report is from 2009. As they weren't using the POCT Hba1C device s in any hospital that I attended in 2009, I can only assume that the cost has dropped significantly!
You know what they say about what happens when you assume. I did see a DCA Vantage machine on eBay for a lot less than the old report. I have to rely on my surgery for my diabetic care so I guess I'll never have the advantage offered to those attending a clinic with one of these devices. Is that preferential treatment? LOL
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I do, but then I don't believe these are POCT devices, they are in fact lab machines that require a lot smaller amount of blood. The sample is sent to an in clinic testing lab rather than done in front of you.
Oh! Do you mean "they" as in the machines mentioned in the NHS report? The machines that the NHS refer to as POCT devices, now I'm really confused!
Further confusion, is that less blood than a pin prick? I see your invite to "keep up with your irregular, random, meanderings", so I assume this is all a wind-up and I'll not waste your time or mine any further.
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As far as I understand it, the new way of doing Hba1Cs at the clinic is with a small amount of blood extracted using the same finger prick device as you'd use for a bg level test. It is about four times as much as an optium test strip uses (on the machine at guys).
My understanding of the definition of a POCT was incorrect. They are POC machines by definition but are used in a lab. The machines themselves now cost about £5,500 to us to buy and can be used at least 5,000 to 7,000 times. If they cost £50 per use I'd be very surprised.
If organisations say it's an average of the last 8-12 weeks then someone along the line has misinterpreted the test or isn't using average to mean "mean".
If red blood cells live about 4 months then unless all your red blood cells were created 4months ago then it's not going to be a mean - in fact it will be biased towards the current day.
But - if your blood sugar level is fairly constant it should give a good average.
Where it will fail is if you have changed - first month of high followed by 3 of low, the first month probably won't be detected.
Nor will the odd day of highs - still not sure how much damage that would do.
A bigger concern - do you want to wait until your next test to find out something has gone wrong with your control.
If red blood cells live about 4 months then unless all your red blood cells were created 4months ago then it's not going to be a mean - in fact it will be biased towards the current day.
But - if your blood sugar level is fairly constant it should give a good average.
Where it will fail is if you have changed - first month of high followed by 3 of low, the first month probably won't be detected.
Nor will the odd day of highs - still not sure how much damage that would do.
A bigger concern - do you want to wait until your next test to find out something has gone wrong with your control.
So don't have a Hba1C test within a few weeks of coming back from holiday if we wish it to tell us anything about our normal lifes.
lindisfel
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It maybe that I am better on holiday if the grilled fish and stakes are cheap and very nice......
4ratbags
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Apparently the HbA1c test is primarily made up from the last month, I have been searching old threads to try and find the exact percentages that a member posted but I can't find it. The breakdown was something like 50% from the previous month, month 2 30% and then month 3 20%.
The break down is different for each person, and is also different for the same person depending on their health over the last 3 months.
