Comparing your meter readings with your HbA1c

[Cliff]

Just another thing to muddy the waters even more, I don't think that HbA1c is a true average of the glycated haemoglobin over 3-4 months anyway. It is weighted to the more recent months (e.g. if the HbA1c was taken at the end of April, then April would have contributed 52% to the result, March 27%, February 14.5% and January 6.5%). No doubt, in reality, it is even more complicated than that.

Andy - You're absolutely right here - there seems a broad agreement that HbA1c is weighted towards the most recent results although there's some disagreement about the exact extent. However, as the various formulae are derived empirically, it should take that weighting into account.

 

[Peter C]

I second Cliff's last post. Don't rely on this average BG to HbA1c calculation, it is just a bit of 'fun'.

Just another thing to muddy the waters even more, I don't think that HbA1c is a true average of the glycated haemoglobin over 3-4 months anyway. It is weighted to the more recent months (e.g. if the HbA1c was taken at the end of April, then April would have contributed 52% to the result, March 27%, February 14.5% and January 6.5%). No doubt, in reality, it is even more complicated than that.

The bottom line is, look after your spot BG results and leave the HbA1c to look after itself! 🙂

The hba1c is reckoned to be weighted towards the last ten days. So some dmers try cheat the thing by going low carb in the run up to the test. they are only fooling themselves of course.
it is complicated, the blood cells involved last up to 90 days ( some of them) so the a1c will reflect values that far back. But glycosulated haemoglobin gets "unglycosulated" and "re-glycosulated" in the course of the 90 days, so its a merry dance anyway.
The HbA1c is a comparatively recent tool ( early 1980s in general practice). The great UKPDS used it as the yardstick in the 1990s research, finding that higher A1cs were definitely associated with more complications. So the emphasis in Britain came to focus on management ( of T2s in particluar) through management of the A1c. This has deflected attention away from SMBG ( particularly for t2s again). The medical establishemnt can't seem to grasp that effective SMBg is the best route to good HbA1cs.

 

[Carina1962]

Thanks Cliff for your reply. My partner keeps telling me to wait until June when i go for my 2nd HbAiC but i'm getting curious and want to have a rough idea of what it will be. For my first HbA1C i bought a home test kit which you send off and my result from them came at 6.4% but my actual doctor's one came at 6.7% so a little difference. I will try what you suggest and see but i will not take it as 'gospel' - thanks very much, very interesting thread by the way 🙂

 

[Cliff]

But glycosulated haemoglobin gets "unglycosulated" and "re-glycosulated" in the course of the 90 days, so its a merry dance anyway.

Peter - that's a really interesting point. The scientific literature tends to describe haemoglobin glycosylation as an irreversible or nearly irreversible reaction but I have found one paper that suggests that HbA1c can reduce very rapidly in insulin therapy stabilisation of newly diagnosed T1 children. I need to do more reading!

 

[falcon123]

To muddy the waters some places are using a new measure. My most recent result was bad but 75 (mmol/mol) is more scary than 9.0 when first heard! Is 75 in old money even possible?

 

[squidge63]

Talking of A1c results my current diabetic clinic I have to go and get blood taken about 2 weeks before my dr's appointment.. at my last diabetic clinic they did a finger prick test which they put in a machine and hey presto my A1c result..

 

[Peter C]

For my first HbA1C i bought a home test kit which you send off and my result from them came at 6.4% but my actual doctor's one came at 6.7% so a little difference. )

hi there. despite the fact that all A1cs are supposed to be calibrated to the standard set by the DCCT in the USA, different labs
use different assay methods and there can be differences in results. About seven years ago I scored 6.9 and was disappointed, the Doc at the Diabetes Centre reassured me - I had gone to a drop in centre for the test instead of the usual hospital clinic. The Doc said their lab ranges were different, the 6.9 on the drop in centre would have been something like 6.4 on the hosp[tal method. Moral of the story - stick to ONE place for a1c tests for consistency.
The difficulties in calibrating different assay methods and different lab ranges is one of the reasons why they are switching to reporting in mmol/mol after June 2011.
if you still have the self testing kit - what was the lab range on that ? and how does that compare to your hDoc's lab range ?

 

[C*5_Dodger]

Hi there,
the difference is becoming less important now because the World has voted to change the way A1cs are measured and expressed. They are switching from % to mmol.
since June 2009 results have been given in %s with the mmol figure in brackets e.g. 6% ( 42mmol). From 2012, or is it 2011 ?, the % will be dropped and we will just get the mmol reading. All those in the 6% club will have to sign up for the Under 40s club.
It is becasue of the difficulty in calibrating the different assay methods and has the benefit of knocking down the widespread belief that the HbA1c is an average of bgs.

Dear Peter,

Just a minor point - they are switching from % to mmol/mol

Warmest Regards dodger

 

[lyndasw]

Thanks Cliff for your reply. My partner keeps telling me to wait until June when i go for my 2nd HbAiC but i'm getting curious and want to have a rough idea of what it will be. For my first HbA1C i bought a home test kit which you send off and my result from them came at 6.4% but my actual doctor's one came at 6.7% so a little difference. I will try what you suggest and see but i will not take it as 'gospel' - thanks very much, very interesting thread by the way 🙂

Carina - can I ask where you bought your home test kit from and how much they are?

 

[Carina1962]

hello Lyndasw, sorry only just saw your post. I will go and get the box and let you know

 

[Carina1962]

Lyndasw: the company is called GlucoMen Aic and it cost around ?24. I ordered it over the phone and you have to send a blood sample and they post out the results to you. I'll be buying it again at beg of April to give me an indication for when i go for my proper one in June. The website is www.glucomenA1c.com

Let me know how you get on if you decide to have a go 🙂

 

[lyndasw]

Lyndasw: the company is called GlucoMen Aic and it cost around ?24. I ordered it over the phone and you have to send a blood sample and they post out the results to you. I'll be buying it again at beg of April to give me an indication for when i go for my proper one in June. The website is www.glucomenA1c.com

Let me know how you get on if you decide to have a go 🙂

Thanks Carina. I have had a mix up with my appointments so I may try this if I have to wait too long for a further test. At least I will have an idea of what is going on.