Hello, I’m new & I have questions about my HbA1c test results.

[Eddy Edson]

Yet anyone looking up HbA1c on this very website sees this:-

HbA1c is your average blood glucose (sugar) levels for the last two to three months

??????

They should change that.

 

[Drummer]

@Welsh mum your change to low carb might be altering the amount of thyroid replacement you require.
I was taking 200micrograms of Thyroxine for decades as my medical team encouraged me to eat carbs as they are so healthy, and then I was diagnosed as a very bad type 2. I went low carb from that moment, and after a while I began to experience all the symptoms of over doing the Thyroxine.
As a recovery of a failed thyroid is unusual, it has taken some time for things to become clear. My prescription is now 125 micrograms daily but I'll have to get an appointment to confess that I am taking rather less than that now to avoid palpitations and night terrors.

 

[Drummer]

!!PEDANT ALERT!!

HbA1c is not an average blood glucose level. It is a measurement of the proportion of haemoglobin that has been glycated. A better way of characterising it would be to say the HbA1c test reflects the average blood glucose level over the last three months or so.

A bit pedantic I know but people, especially newbies get confused over the various tests that are used and anything we can do to be technically accurate must help in keeping things clear.

Plus there are the awkward ones like me, who reduce their carb intake to try to lower their HbA1c - I reduced 10gm a day, after thinking I'd try for the 30s rather than 42.
For a whole year I waited, seeing my after meal number were down, watching the averages on my after dinner tests creep lower as the days passed and finally I got the test result. 42.

 

[Martin.A]

They should change that.

Then so should the NHS and the National Institute for Health & Care Excellence (NICE), which both say:-

The HbA1c test is a measure of your average blood sugar level over the last 2 or 3 months.

 

[Eddy Edson]

Then so should the NHS and the National Institute for Health & Care Excellence (NICE), which both say:-

The HbA1c test is a measure of your average blood sugar level over the last 2 or 3 months.

Yes, they should also change that.

 

[silentsquirrel]

There is a subtle difference between "is your average BG" and "is a measure of your average BG".

 

[Eddy Edson]

There is a subtle difference between "is your average BG" and "is a measure of your average BG".

Understood, but I think "measure" is still misleading in practice.

 

[trophywench]

Well if we want to really be pedantic of course nobody should ever use the word 'average' when discussing any HbA1c result since the most recent of those 3-ish months has a disproportionate effect on those results - like the latest tranche c.60% of it, then the middle tranche c. 25% and the furthest back the other 15% - hence never ever an average. Or it might be 65/25/10.

 

[silentsquirrel]

Well if we want to really be pedantic of course nobody should ever use the word 'average' when discussing any HbA1c result since the most recent of those 3-ish months has a disproportionate effect on those results - like the latest tranche c.60% of it, then the middle tranche c. 25% and the furthest back the other 15% - hence never ever an average. Or it might be 65/25/10.

So related to a weighted arithmetic mean (weighted average) rather than an ordinary arithmetic mean.

 

[Exflex]

Don't forget the HbA1C is an average blood glucose level over the previous 3 months prior to the test so unless you have been doing a low carb regime for the whole of that time it will not fully reflect the impact of that.
Also you mention ferritin levels and that is also something that can affect the HbA1C test result and certainly the difference between 42 and 43 is not significant.

Sorry to hijack your thread @Welsh mum, my recent diagnosis of Pre-D came with low ferritin (doc put me on 5mg for 3 months). @Leadinglights can you explain how ferritin affects HbA1c please, if you don’t mind. PS I’m eating more leafy greens now.

 

[everydayupsanddowns]

LOL! Apologies for the thread drift @Welsh mum - this os what happens when forumites get let loose on your thread and get all excited about odd details here and there. I hope you can bear with us!

It will be interesting to see how your GP surgery’s A1c accords with the postal test you have been obtaining privately.

I was working with some researchers on a project which extended over the lockdowns, and some of the follow-up HbA1c checks had to be taken via post using capillary blood rather than veinous blood from the arm into one of those vials. I ended up working on the instruction leaflet which tried to ensure that the samples were as likely as possible to produce a reliable result, and recall that there were quite a few steps and precautions needed.

I’m guessing the service you have been using have their own protocols in place.

Over the decades I’ve been juggling my diabetes numbers I’ve seen a few unexpected rises and falls in HbA1c results. Mostly relatively predictable from my fingerstick glucose patterns, but not necessarily always so.

It is always tempting to try to read behind the numbers of each test and attempt to identify what may have caused something to rise or fall - especially if the result is not what you were expecting…

In general I’ve ended up with a system of trying to look for overall trends from several results, and to happily shrug and accept a few wobbles here or there.

Let us know what you find out when your next result comes in 🙂

 

[everydayupsanddowns]

Sorry to hijack your thread @Welsh mum, my recent diagnosis of Pre-D came with low ferritin (doc put me on 5mg for 3 months). @Leadinglights can you explain how ferritin affects HbA1c please, if you don’t mind. PS I’m eating more leafy greens now.

It looks like there might be a relationship, but I’m not sure if it is believed to be causal or reflective

Serum ferritin has correlation with HbA1c in type 2 diabetic patients - PMC

Serum C-reactive protein (CRP) and ferritin are two acute phase reactants. CRP may be related to metabolic syndrome and ferritin which in turn could cause resistance to insulin and dysfunction of b cells of pancreases. The aim of the study was the ...

www.ncbi.nlm.nih.gov

The Hb in HbA1c is haemoglobin (in red blood cells). So anything that affects the numbers and function of red blood cells could I suppose interact with the A1c that is measured. People with a low red blood cell count or anaemia sometimes use Fructosamine instead of HbA1c to monitor their general glucose management, because anaemia can impact HbA1c results.

Interesting that the study linked above found that ferritin levels dropped as hyperglycaemia and HbA1c reduced @Welsh mum

 

[Exflex]

It looks like there might be a relationship, but I’m not sure if it is believed to be causal or reflective

Serum ferritin has correlation with HbA1c in type 2 diabetic patients - PMC

Serum C-reactive protein (CRP) and ferritin are two acute phase reactants. CRP may be related to metabolic syndrome and ferritin which in turn could cause resistance to insulin and dysfunction of b cells of pancreases. The aim of the study was the ...

www.ncbi.nlm.nih.gov

The Hb in HbA1c is haemoglobin (in red blood cells). So anything that affects the numbers and function of red blood cells could I suppose interact with the A1c that is measured. People with a low red blood cell count or anaemia sometimes use Fructosamine instead of HbA1c to monitor their general glucose management, because anaemia can impact HbA1c results.

Interesting that the study linked above found that ferritin levels dropped as hyperglycaemia and HbA1c reduced @Welsh mum

Thanks for the link. Although the main body of the article is quite technical, and admittedly beyond my comprehension, the conclusion is easier to understand, viz ‘Based on our results, serum ferritin decreased after decline of patients’ blood sugar which might be used it as one of the diabetes control indices for diabetic patients’.
In my case blood tests showed my ferritin below lower limit but my blood sugar (HbA1c) above normal at 44.
Anyway, I’m increasing greens, and taking a 5mg ferritin tablet daily.

 

[Martin.A]

…

In general I’ve ended up with a system of trying to look for overall trends from several results, and to happily shrug and accept a few wobbles here or there.

Me too. In the weeks and months after diagnosis I was looking to see if the trend was downwards (it was). Now I'm looking out for an upward trend that would suggest something's going awry (so far no signs).

 

[Drummer]

Well if we want to really be pedantic of course nobody should ever use the word 'average' when discussing any HbA1c result since the most recent of those 3-ish months has a disproportionate effect on those results - like the latest tranche c.60% of it, then the middle tranche c. 25% and the furthest back the other 15% - hence never ever an average. Or it might be 65/25/10.

And as I found out, just lowering blood glucose levels doesn't bring about a lowering of HbA1c - there are unregarded factors involved.