Planned changes to the way in which HbA1c measurements are reported have been postponed from June 2011 until October 2011 basically because no one understands the changes and people are understandably a tad underwhelmed and befuddled by them.
This dog was hoping one of the ShootUp authors would have gotten their heads around this by now and actually written about the planned changes to move from reporting HbA1c’s as a percentage eg 6.5% to a figure in mmols/mol eg 48 mmol/mol. Sadly, both Tim and Alison have remained resolutely silent on the issue, probably because they’re struggling to care and suppressing irritation that we’re wasting time and effort changing a system they’re comfortable with. But that’s just this dog’s opinion.
Diabetes UK have the full story: http://www.diabetes.org.uk/About_us/News_Landing_Page/Change-in-measurement-of-HbA1c-delayed/
For more info and a calculator to help convert old to new try here: http://www.diabetes.org.uk/hba1c
Theoretically these changes will help us to standardise results across the world, allowing for better comparisions in research trials etc. But, on a very selfish, individual level, Neville is absolutely right. I understand the % system and of all the pancreatically related things I should be dedicating some extra brain power to, converting my HbA1c results from the whizzy new format, to the one my brain has been used to for nearly 30 years is not even on the list. I feel like a pensioner who’s trying to buy half a pound of apples but the store will only sell them in kilos!
As I currently use crude calculations to convert my HbA1c to a figure I understand (mmol) then how will this affect me apart from having to change the figure I mulitply by? If I was getting these results daily I’d be concerned at the hassle but as it’s 6 monthly is it really that big a problem?
And can anyone who has read all the detail explain why the resulting figure can’t be expressed as the standard measure given by my trusty Aviva Nano as it appears to use a similar measuring unit?
Trying to answer your second question would involve more research than I’m willing to put into this at the moment, sorry! Re your first, in my mind I know exactly what I consider good/bad/ok for me when it comes to HbA1c, when the results come in I understand them immediately, I don’t even have to think about it. Now I’ll have to work it out. Sheer laziness and classic response of someone being asked to change when they don’t perceive the change to deliver any great benefits to them. There is so much to think about already, I’m not a huge fan of adding extra stuff to the list if it doesn’t deliver huge benefits to me.
I’m not gonna comment on it as I can’t be bothered… I have already shared my musings on the subject of the A1c as a test so changing the measurements won’t really effect us that much.. As Dave mentioned at least its a a daily figure.
I think most of us will simply refer to the old % value for years to come anyway.. Bit like when the UK went imperial.. 【ツ】That’ll be 2d my love..
Bugger i’ve left a comment!
@mikeinspain – 😆
It makes me laugh that a bunch of analytical chemists finds it difficult to compare one percentage figure with another! Their brilliant solution is to invent a completely new measurement that means nothing to anybody! You’ve got to laugh 😀
Slightly more seriously though, the fourth paragraph of the DUK article shows whose benefit this is really for “…This will make comparing HbA1c results from different laboratories and from research trials throughout the world much easier.” How many diabetics routinely compare HBA1C results from different labs around the world? Not many I suspect.
But really, the “switch-off” is unnecessary. Since labs have been producing two numbers per test since 2009 and it hasn’t led to the collapse of civilisation, why not just carry on? Give us thick diabetics the % figure and if any member of the IFCC wants the mmol/mol number it is there for them to compare to their hearts content.
[end rant]
TBH, I couldn’t care less. As long as someone tells me the acceptable range I should be within, I’ll get along with it just fine. I’ve not really got the hang of the percentages anyway, so I guess that helps me a bit, but mostly it’s just a simple matter of being told ‘you are x, you should be between y and z, so that’s fine/terrible’.
Hmm, if I swapped the y and the x around that would almost be funny 😛
On this topic, can anyone tell me what a mol is?!
I believe a Mol can be anything of these http://en.wikipedia.org/wiki/Mol 🙂
Sorry, I’m led to believe that is stands for microlitre.. I’m pretty sure I will be corrected somewhere.. But I don’t care cause I used wikipedia 【ツ】Yeah!
@mike: So mmol translates to one billionth of a litre, and presumes that glucose has volume, but no mass…this is taking weight loss to unreasonable extremes 😀 (official definition says this about a mole (mol) “The mole is the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kilogram of carbon 12.” [14th CGPM, Resolution 3])
Never having considered what a mmol is before I’m a little concerned at how close to homeopathy our measurements are. However, sometimes I’m convinced my blood has a ‘memory’ of sugar rather than an actual presence!
I’m definitely in the ‘tell me what range I need to be in’ group of thought.
Right, where’s my science hat…
“Mol” in this case is short for mole. A mole is just a number (roughly 6.02 x 10 to the 23 – sorry, don’t know how to do superscript). And “mmol” is short for millimole, ie. a thousandth of a mole.
In the old HbA1c measurement they told you what percentage of your haemoglobin (stuff that makes blood red) was glycated (had sugar stuck to it). The more glucose present in your blood, the more glucose gets stuck to your haemoglobin. And the more your blood glucose level decreases the more glucose gets unstuck from your Hb. Which is why you can have a pretty decent HbA1c by rollercoaster-ing your way through life!
The new measurement tells you how many millimoles of glycated haemoglobin molecules there are in every mole of haemoglobin. They could have measured the number of molecules of glycated haemoglobin in, say, 1000 molecules of haemoglobin, but chemists like measuring things in moles. Which is why I’m not a chemist.
The unit mmol/mol looks a lot like the mmol/l one used for your common-or-garden fingerprick tests. However the fingerprick tests measure the number of millimoles of glucose in every litre of blood plasma. Or in every litre of whole blood if you have an old meter. But that’s another story!
As I understand it, part of the reason for changing the unit used to report HbA1c is that the numbers we see everyday are very similar to the ones produced by measuring HbA1c as a percentage. This leads to confusion as some people look at their HbA1c and think that that number is their average blood glucose level. In fact it’s just coincidence that the numbers look so similar and they aren’t directly comparable.
Speaking of confusion, I’ve probably just left the “DOC” well and truly befuddled with my little essay. Back to lurker-hood I go…
@alice: Sorry to infringe on your wonderland where “glucose gets unstuck from Hb”, but glycosylation is irreversible (she says while replacing coxcomb with mortarboard…well, at least two years of uni chemistry before I decided I was dying of cancer, dropped out and woke up in hospital with a diagnosis of diabetes…thank goodness I’m not a diagnostician ;))
@seasiderdave I once (when very bored on the tube..) attempted to work out the amount of glucose in the average person’s bloodstream. I came up with something the equivalent of the amount in a jelly baby’s foot. As I say, I was on the tube so I may have lost a few zeros somewhere!
That’s why we always should eat diabetic Jelly Babies (without feet) 😀
but you have to start with the head first surely??? 【ツ】
@Alice @Ckoei – thank God for readers like you two to do the science bit (a la L’Oreal adverts). I was very firmly an arts / law student – hence the lack of science on the blog. @Alison, however, with her law degree is so much for sciency than I am *cough*
@Alice I’m not sure about your reasoning that changing the measure makes the results a number that looks dissimilar to our usual blood test readings and therefore reduces the risk of people thinking they’re the same.
This works in the UK, but this change is to align things globally, and the US market measure their blood glucose in mg/dL which means their results will be very similar to the new HbA1c results. ie 6.5% HbA1c will equate to 48 mmol/mol in new money. 48 in American is a perfectly recognisable blood sugar, equating to around 2.6 in English speak. So we’re actually just shifting your issue (if it is indeed an issue) from our shores across the Atlantic. Not a bad thing in itself obviously 😉 but not a rational rationale for a change.
@mikeinspain Head first, no question
@Tim My father is an engineer, science has been unavoidable throughout my life! That said, my only real interest in it is when it’s relevant to sorting out the pancreas mess.
@Alison – I take it all back dearest co-writer!
@Ckoei I think you’re absolutely right about glycation being irreversible. I thought it was too until I asked my old consultant how you can get a lovely A1c when you’re high a lot of the time and was told that being low a lot of the time evens you out because it’s in equilibrium. Don’t know why I trusted him on this, didn’t on anything else! Maybe I should ask my current consultant, who seems to have his head screwed on reasonably tightly.
@Alison – what I meant was that I’d heard that clinicians (over here at least!) were open to changing the unit for many reasons including reducing confusion for patients. I don’t think it was an actual motivating factor for doing so – just a pro rather than a con. Personally I don’t think it’s an issue at all. But then maybe it’s because I don’t see clinic-fuls of people that I haven’t bothered to educate properly about interpreting their various test results…but that’s another issue!
@alice: You could’ve smacked me for my “glycosylation is irreversible” statement – that’s the claim to fame of uncontrolled, non-enzymatic glycosylation (aka glycation), hallmark of diabetes…we should’ve swapped terms, then we’d both be spot-on 🙂 (maybe your old doc’s terminology is as befuddled as mine 😳 )
Aaah, that explains it, @Ckoei. Let’s just say everybody’s right, then everybody’s happy and we can all live happily ever after, glyc(osyl)ation notwithstanding…
Bugger happy endings! I’ve gone autoimmune on part of my irreversibility-proclamation:
“Glycated hemoglobins are hemoglobin components formed through a two-step non-enzymatic reaction between hemoglobin and blood glucose. The first step consists of the formation of a reversible aldimine form of hemoglobin to glucose linkage. In the second step, the labile aldimine form is converted slowly to the stable and irreversible ketoamine form through an Amadori rearrangement.”
So @alice’s doctor is right, as long as we don’t two-step 😉
The only thing I _know_ about moles is that they dig up my potatoes…