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Is HbA1c a reliable indicator of diabetes control?

Have you found HbA1c to be misleading about your control?

  • Yes

    Votes: 4 23.5%

  • No

    Votes: 13 76.5%
  • Total voters
    17

IanD

Well-Known Member
Messages
2,429
Location
Peterchurch, Hereford
Type of diabetes
Type 2
Treatment type
Tablets (oral)
Dislikes
Carbohydrates
I have good reason not to trust HbA1c as a guide to my control:

7-8 years diabetic T2 I was suffering crippling peripheral neuropathy, & various other problems.
HbA1c was 6.8 (50.8) which Dr did not consider the cause of the problems - basically diabetes is a progressive condition, & my diabetes was progressing as expected. Sad.
That HbA1c corresponded to my finger prick tests.

Dr suggested hospital tests but first I came on this forum, & took the low carb advice - cutting out all the obvious carbs.
Immediately my readings improved, & soon my health, so that in 3 months I went from crippled to playing tennis again.
As an experiment, with high carb food, I found that testing an hour after a meal gave readings in the teens, so that it became apparent that HbA1c - an average of 2-3 months blood sugar gives NO indication of highs & lows during that period. It's the highs that do the damage. [I was never in the hypo region.]
On the low carb diet I rarely go above 9.
Now - diabetic for 15 years, at 76 y-o, I am fully fit & without diabetes problems - & still play tennis at club standard.

The last HbA1c=49 (6.6).

It seems to me that the measure relied on by doctors is not a good guide.

One last thought: I suspect that the HbA1c units were changed to make it more difficult for diabetics to relate HbA1c to their finger tests.
 
At a Hounslow support group meeting a year ago a rep from Abbot introduced the Freestyle Libre continuous monitor.

Then it was suggested that it would show up highs & lows in a way that HbA1c could not.
 
I agree
 
Hba1c is a c.12week 'integrated' b.g.
To put it in mathematical language, it is the area under the graph.
It does not see the highs and lows with time.
I have brought my hba1c down to 45 from 50 and I now have been having my worst hypos.
Derek
 
Last edited by a moderator:

I also have to agree because of my misdiagnosis.
But then when I had control it proved that I wasn't diabetic!
But, however, it helps in treating the condition and shows how well the patient is responding to meds and diet!
 
IanD said:
it became apparent that HbA1c - an average of 2-3 months blood sugar gives NO indication of highs & lows during that period. It's the highs that do the damage.
Click to expand...
Absolutely 100%.
 
My finger prick readings and HbA1c are never all that close, even when using the conversion tool.

I've had a period of using the Libre to see if I could see where the differences might have arisen. The Libre, however, indicates that I really don't have great peaks and troughs, aside from overnight when I can run really quite low, without incident, and I rarely see any real directional arrows, which indicate rapid rises or falls.

If you are aware, as well as the ability to scan the sensor at will, the sensor collates and the reader facilitates a download, via USB cable to my laptop. The meter software provides some fairly basic graphs, but of course, something like Excel can put it through a few more hoops.

As the Libre pretty much aligns with my finger prick testing, I am just having to accept that for me, the differnce is there and probably will continue to be so, but at least I do appreciate I have no great glucose alpine regions.
 
My A1c never seems to correlate with the readings I'm getting on my meter. Given the haemoglobin anamolies that can affect it's accuracy - and I seem to recall the prevalence is quite high in Celtic type populations - I don't understand why it has become the standard instead of the fructosamine test. My suspicion is maybe a cost difference?
 
AFAIK, the WHO says HbA1c should be the standard test (for screening, at least) unless there are clinical reasons why not in a specific person. Haemochromatosis rates are higher in Celtic populations but I don't know about other anomalies. The WHO has to make recommendations for all ethnic groups. I haven't looked at their detailed statements but perhaps they mention these issues. In general, if policy makers are evaluating two options that appear to have similar reliability in most people, then they will go for the cheaper option, because there is always something else that needs the money. It doesn't make sense to use a more expensive test for everyone when the number of people needing that test is small. I think the trick is to identify which people need the other test.
 
Indy51 said:
Fair enough @CatLadyNZ - Though my assumption was that Ian was referencing UK standards, not international.
Click to expand...
Yes I assumed that too. Hopefully UK policy makers take the Celtic groups into account along with all the other groups that live in the UK. I think they take notice of WHO recommendations or at least use the same studies but I don't know to what extent. NZ guidelines are partly based on the Scottish ones (which I like, being of half Scottish ancestry, lol).
 
Hey I agree with the original post too. I have diabetes caused by pancreatitis from alcohol abuse. Sober 3 years now but hard 10 years on my body. My monitor always reads above 15 and that's the lowest I get during the day. Always goes up if I use energy even if I've not eaten. But my hbac1 is 6.7 and has been since being diagnosed 4 years ago. They tell me I'm doing very well but my monitor and body says different. I test around 5 times a day too. Never catching a low. Dr tells me that I just miss the good readings which I thinks s load of ****.
 
My quite low HbA1c of 43 has some parts of my healthcare crew convinced that I’m having loads of hypos, because as a T1 I must also be having loads of spikes. My Libre traces have proved that I have neither, so in my case, my HbA1c has given them very false impressions of my control.
 
In some people it can be reliable. The problem is, which people?

There are many factors that affect the HbA1c test itself, such as an red blood cell abnormalities, how long our red blood cells live longer than the standard 120 days or die well before that period, other medical issues such as thyroid problems.

Then there are the swings and roller coaster issues of our blood sugar levels. It is possible for a person to have huge and dangerous swings up and down but have the same HbA1c as someone that has no swings and virtually flat lines. This is known as the fallacy of average.

A quick Google brings up all these anomalies. There has been a lot of research. The advent of CGMs and Flash Monitors has brought this about.
 
A very high A1c is a reliable predictor of bad control....... (Unless problem with red blood cells, hence a blood cell count is done when someone first gets a high A1c)

A low A1c tells you much less.
 
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