Fundamental misunderstanding

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mhtyler

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I've been working to increase my knowledge of diabetes for a few years now, but a video I watched on YouTube leads me to believe there is something fundamental I don't understand. Here is the link to the video in case you'd like to see it:

The video is about doing your own A1c test at home. Here is what blew me away. I've had an A1c of 7 for the last few quarters at least. She says, that means my average glucose is 154mg/dl, or 8.4 mmol/L. Isn't A1c in mmol/L? If so, why is my personal measurement going to be higher than my A1c? I actually thought it would be the other way around. I'm very confused. Somebody, please help clarify this for me. thanks in advance.
 
Because the personal finger prick tests are measuring a different thing than hba1c even though the units used are similar

Hba1c can be reported in % (usually USA) or mmol/mol. It represents the amount of glucose the red blood cells have been exposed to in their life time. The average lifetime is around 12 weeks. So this test measures glycation of old, middle aged and new cells all,of which will have had different amounts of exposure. Hence the fact it’s seen as an average of the last 3 months and any changes take that long to be fully represented.

Fingerpricks measure blood glucose as it is right now in this moment. Levels can changed in minutes let alone hours, days or weeks. They are reported in mg/dl (mostly USA) or mmol/L (uk & Europe).

When the say hba1c is equivalent to an average blood glucose reading of x y or z that’s making the assumption you’d have identical blood glucose levels all the time - which you don’t. To make an average blood glucose number be as accurate as possible in predicting hba1c you need a broad range of figures across the day and from all situations where you capture the lows (eg fasted) and highs (soon after meals)

One is not a better test than the other. They just tell you different things and are both useful for different reasons.

It appears your A1c has been reported in %
 
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If you're going to research diabetes online I'd stick to reputable healthcare sites, not YouTube (or social media).
 
Martin.A said:
If you're going to research diabetes online I'd stick to reputable healthcare sites, not YouTube (or social media).
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Whilst I do agree in one sense, those sources can be useful for giving you an idea what to research on more recognised medical sources.

That said reliable, accredited and well know medical doctors do post on the internet too. It can be hard to tell one from another though without researching the source as well as the information.

If I had only followed nhs official advice or even what this diabetes organisation right here had advised I’d never had reached remission or know a fraction of what deeper diving of my own had taught me.
 
mhtyler said:
Isn't A1c in mmol/L?
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As above, HbA1c is mmol/mol (in the UK at least) & yours won't be "7", unless you're talking about the old percentage measurement. In which case your looking at 53 mmol/mol, which does correspond to 154 mg/dl.

So three things:
  • Be aware of the different units of measurement & make sure you're comparing like with like
  • Those on here who have used home HbA1c kits report poor results
  • YouTube is generally for entertainment, not medical information, especially when they're trying to sell you something
 
HSSS said:
Fingerpricks measure blood glucose as it is right now in this moment. Levels can changed in minutes let alone hours, days or weeks. They are reported in mg/dl (mostly USA) or mmol/L (uk & Europe).
Click to expand...
I've always understood that a fingerprick is only measuring glucose in the moment, but I see now that I never really understood that A1c and a glucose measurement weren't the same thing. I just assumed that an A1c is an average of my glucose over a 3 month period, and so they were using exactly the same scale. Apparently though, if I had an accurate average of my glucose in mmol/L and it was 8.4 then my A1c would be 7. Is that correct?
 
This chart is helpful. Top two lines are hba1c. Bottom two are average equivalent blood glucose
 

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HSSS said:
Whilst I do agree in one sense, those sources can be useful for giving you an idea what to research on more recognised medical sources.

That said reliable, accredited and well know medical doctors do post on the internet too. It can be hard to tell one from another though without researching the source as well as the information.

If I had only followed nhs official advice or even what this diabetes organisation right here had advised I’d never had reached remission or know a fraction of what deeper diving of my own had taught me.
Click to expand...
I agree. YouTube was years ahead of my own doctors. Yes, I know there's a lot of baloney on there too, and I'm careful to verify things. That said, I've been to 5 different doctors over the last 8 years. Once I was told I had T2D not a single one of them EVER gave me a single bit of advice on diet, or exercise, or whether it was possible to go into remission or ANYTHING else. What they said in short was: Here's your pills, here's your meter, pay your bill on the way out. My current doctor will answer questions but has never offered advice on anything, ever. American GP doctors write prescriptions....that's all. Why do you think I'm on a UK site? The American Diabetes Assoc. is a joke.
 
HSSS said:
This chart is helpful. Top two lines are hba1c. Bottom two are average equivalent blood glucose
Click to expand...
Great chart, but I need one that reports in A1c numbers as they're reported over here. My confusion seems to have started because the A1c number here looks just like a glucose number in mmol/L, when its apparently in mmol/mol. Is that correct? Whew...
 
HSSS said:
This chart is helpful. Top two lines are hba1c. Bottom two are average equivalent blood glucose
Click to expand...
This one pops up quite often on here, too:-
 

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Martin.A said:
If you're going to research diabetes online I'd stick to reputable healthcare sites, not YouTube (or social media).
Click to expand...
Martin, I agree with you in principle, but I do try to verify what I'm seeing on reputable sites, and I've found some Youtube that I trust. As I told HSSS, I'm well aware of the nature of Youtube and the Internet in general, but if I'd relied on my doctors I'd be looking at severe neuropathy and eventual amputation...at least. In short, Youtube is more helpful than my doctor.
 
mhtyler said:
I don't understand the nomenclature ...yet, but it appears that my A1c gets reported in in % (DCCT/NGSP)
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Which is how it used to be reported, but the recommended units have changed (in the UK partly because of the confusion because the numbers can be quite similar to BG in mmol/l (though HbA1c was %, sometimes people omitted that)).
 
Martin.A said:
This one pops up quite often on here, too:-
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Yeah, this one works better for me. I use the top number a1c, and I do know how to convert the bottom to mg/dl. I'm embarrassed that I though top and bottom meant the same thing, but hey, I'm American...we don't speak mmol...lol. I can modify the bottom one by adding mg/dl underneath at it will be just as though I knew what I was doing!
 
Bruce Stephens said:
Which is how it used to be reported, but the recommended units have changed (in the UK partly because of the confusion because the numbers can be quite similar to BG in mmol/l (though HbA1c was %, sometimes people omitted that)).
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Indeed. I didn't know I was confusing the two.
 
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