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Type 2 Hba1C v BG

L

Limelight

Member
Messages
6
Type of diabetes
Type 2
Treatment type
Diet only
I was diagnosed type 2 two years ago and have managed my diabetes with diet alone so far. When my doctor checks my levels it is always my Hba1c which is measured but most people on the forums talk about blood glucose levels. How does blood glucose level equate to Hba1c - I am a bit confused.
 
Hi. Yes, the HBA1c is a very reliable test as it shows your average blood sugar over the last 3'ish months. Blood glucose levels checked with a glucose meter are good for spot checking the effects of food and whether you are 'spiking' or going too low but the HBa1C is of more use to determine medication next steps if any.
 

I agree, unless a good a1c is the result of a lot of highs and lows. That can happen too.
 
The A1c reflects both premeal (fasting) and postmeal glucose levels. The fasting level of course offers no information about glucose tolerance (control during and after the meal).

The A1c is clinically more robust and convenient, which has made the professional community like it. It is supposed to be the average of blood glucose over the the last 12 weeks, although the immediate 4 weeks make up half the impact on the test result. Therefore, the patient need not fast in advance. Also, its inherent test error is quite smaller than the fasting BG's inherent test error (something like 7% vs. 12%), which is to say, the A1c produces more consistent results.

It is systematically too high in some and too low in others. Despite that, I use it several times a year, thinking that the ups and downs should be accurate even if the absolute values are not, and besides, there is no better alternative.
 
The two levels do not equate to each other if I am pedantic. The reason is, as stated above, that the Hba1c is a reading representing your blood glucose levels over the past 2 to 3 months and you would have to behave for that period of time to affect that result. The instantaneous blood glucose reading tells you what the level is right now and you have some choice over when you take that reading. If you always take it when your blood glucose is low then averaging those readings will give you a low reading. Similarly for high readings. In short, when you take the reading affects the result which is not the case with an Hba1c.
 
Hence hba1c is a lifestyle diabetes test and behaving for a week before one goes to the doctor will not give a good result!
 
The problem with hba1cs is it doesn't show the variance, that's where BG finger prick testing comes in. Think of your BG levels on a graph, you could be skimming along in the 5s most of the day and night but peaking after meals into the high teens, causing damage, but your hba1c result could potentially be in the 6s and you and your Doc think that's great keep doing what you're doing........!
 
@Limelight

Her is the answer.
The correct term for the general concept of "HbA1c" is " Glycated hemoglobin".
Hemoglobin in adults consists of Hemoglobin A (HbA), A2 and the traces of F ( fetal hemoglobin).
The HbA contains a small amounts of other hemoglobin's, so-called HbA1 or rapid hemoglobin's.
HbA1 consists of several fractions: HbA1a, HbA1b and HbA1c. HbA1c is the major fraction.
Glycated hemoglobin (HbA1c) is a connection between carbohydrates (glucose, sugar) and usually valine-amino acid in the hemoglobin molecule beta chain. There are two main steps in the chemical
reaction between the HbA and the carbohydrate's. In the first step is formed reversibly ( formed and transformed) a so-called aldimin-context ( "Schiff-base") , which is then slow (days) at a so-called "Amatory" rearrangement irreversible (no way back) is converted to a stable ketoamin. It is demonstrated that the conversion of 91% of the newly formed aldimin to stable ketoamin takes 22 days. The formation of Glycated hemoglobin is in progress whole lifetime off the erythrocyte's ,depending on the blood glucose level. High glucose level , the more Glycated hemoglobin will be formed. Glycated hemoglobin HbA1c, will be an expression of Glykemic control of glucose in the blood in the last 3 to 8 weeks lead sampling and are expressed usually as a fraction of total hemoglobin. The short-term increase and decrease in glucose levels will have little effect on the Glycated hemoglobin, as it will only affect the amount of aldimin that is removed before identification off the Glycated hemoglobin.
HBA1c is not an average estimate for BG it is an expression for the persons Glykemic control .
Look at this:
http://www.diabetes.co.uk/hba1c-to-blood-sugar-level-converter.html
https://en.wikipedia.org/wiki/Glycated_hemoglobin
 
Last edited by a moderator:

Limelight, many T2s who use the forum need to test their their bloods on a daily or regular basis and some others have to do their finger prick tests due to the style of medication they are using to control their diabetes.

Most T2s who control their diabetes using diet alone find their Doctors encourage them to test themselves at home, but some of us choose to. We do that to try to learn how our bodies are coping with what we eat and drink, without waiting several weeks to find out. I look upon it as my immediate feedback from my body.

Over time, I found some foods were better for me than others and some things I just needed to avoid really.

The numbers we get from our meters are different to our HbA1c as they're measure differently, which is a real pain. This link explains the differences.

http://www.diabetes.co.uk/hba1c-to-blood-sugar-level-converter.html
 

¿Qué?
 
@luna50 It seems you have a liking to using an over complex explaination to try to make a point.
I prefer to make use of Occams razor i.e "Everything should be made as simple as possible, but not simpler." (as attributed to a humble patent clerk, Albert Einstein)
I, and many others realise that HbA1c is not an "average of BG" but is a measurement of the glycation levels of surviving RBCs and that it tends to tend towards the aveage.
IMHO, the mark of the good communicator is that he/she can explain without wrapping up in technicalities which merely attempt to glorify the communicator.
 


There are people with different needs. This forum is read from many people. You can not represent all people in the world. My explanation off HBA1c is not to glorify me , but to glorify the science. I am always ready to answer on all the questions that may be asked.
I can see you have understand that HBA1c is not an average of BG.
You see, the text has not been complicated.
You tell me your problem. Some people who like to read the text as the text must be, if I write very popular text ( with LIX like in Donald Duck) , then this people will laugh on me.
Latin: " Quod hominem tot sentential".
It is impossible to make all the people CONTENT.
Be happy and remember to live

PS Take newer starting point from your own person. There out are people who know more then you and people who know less and you. You must accept that. Otherwise all the text you do not understand will be for you "Margaritas ante porcos"
Hallo Collieboy
I have T2DM like you, but I am not your coleague!
 
Can we all be polite and courteous please. I have removed the rude comments and responses
 
Once again, a thread takes a turn for the worse haha

I'm pretty sure the diabetes.co.uk link I posted explained the HbA1c test to a tee.

There was no need for the same answer to be posted 4 or 5 times and more importantly the petty arguing.

@Limelight, I hope you got your answer and realise that not every member of this forum is a complete idiot

Grant
 
One thing I agree with is we are all different.
Anything wrong with different?
@luna50 I can only speak for myself but I'm reading and writing inbetween other things so to digest heavy medical terminology can be counter productive. Especially if you've copied and paste from one of your books.
In layman's terms please.
 
slip said:
The problem with hba1cs is it doesn't show the variance, that's where BG finger prick testing comes in. high teens, causing damage, but your hba1c result could potentially be in the 6s and you and your Doc think that's great keep doi
Click to expand...

Exactly, A1c doesn't show the swings. If hypos are frequent, this partly cancels out highs of 8.0, 8.5. My BG rises to between 7.5 and 10.2, then all the way back down within 2 hours. The resulting A1c is in the prediabetic range, but the postmeal rises of magnitude 3.5 to 5.5 are disturbing. Scientists suppose that rises so large can't be harmless, but they don't yet have a measure of how large a risk factor the large rises represent, or what specific harms they cause.
 
I have to agree totally.
That is why I believe you should treat a hypo gradually, if you can. Type1s might have no choice if a comatosing low.
The fast change in the inflammed vessels can cause the damage.
Although none diabetics also have bg swings but not as aggressive.
Hba1c is just a guide but the only one at the moment of any help to the medics.
The cost of making potable hba1c testers would be horrendous, hence the meters we have today. Once again just a guide not 100% accurate. A guide to whether the trait is higher or lower.
@Brunneria has a great chart which shows what your hba1c result is equivalent too in mmol/l (meter readings measurement).
 
I am sorry if some one find that my text have to much heavy medical terminology.
I do not thing such. This subject can't be explain more simplified, without to lose a meaning.
The subject is much more complicated, but I can not do that better. It is not copy/paste, it is my own knowledge about the HBA1c , collected from different text's about that.
If someone has a questions about the part's of the text, then I will be pleased to answer.
Moreover I do not understand the critic on me because I have used time to explain what HBA1c is.
Many of you write links to the internet places with a very heavy medical terminology. What is the difference?
Is that something to do with " the who-do-you-think-you-are attitude" ???
 
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