HbA1C Test

Hey @thaddydv
Have you had a look around www.diabetes.co.uk?
As well as the forum, this is an amazing library of easy to understand short articles about diabetes which answer question such as the ones you posed above and more.
Take yourself to the Home page of the site, type "Hb1AC" into the Search box in the top right of the page and you will find this page listed as the first one on the site: https://www.diabetes.co.uk/what-is-hba1c.html
It will tell you exactly what you want to know and more.

I highly recommend taking a look around the site. There is so much to learn about diabetes. Some pages will help you now and some are useful to remember for future reference.

HbA1c represents the average over 3 months, it doesn't just respond to high values. An HbA1c of 9% is equivalent of an average glucose level of 11.8 so something is wrong with the figures. The are reasons to do with red cell lifetime and anemia that can make HbA1c inaccurate but that is unlikely to account for your discrepancy. I would check you have been given the right result if you haven't already done so

It looks at how the red blood cells have responded to glucose over their life time. Each cell typically lasts 8-12 weeks so that’s the period it averages over.

As far as why your reading don’t correspond there’s a number of reasons. Apart from an error in the the test or it’s reporting, very occasionally it can be anemia or other conditions affecting rbc and their longevity. More commonly your testing is missing the highs.

270 times in 3 months is less than 3 times a day. Easy to miss spikes. Perhaps food is not rising til after you test and maybe it’s quite high or has risen and fallen before you test. Perhaps food eaten at a meal you don’t check is doing more damage than you realise.

What testing regime do you use?

Your second test is likely to be the lowest of the entire day. It’s past any dawn phenomenon, it’s before food and after a decent walk.

What are you eating at each meal. That might give clues if you are missing rises. Have you ever tested the before and after of each meal? Is it identical every single day?

Test immediately before each meal, then two hours after first bite.
If the results are still not in line with your HbA1c then test before and 1,2 and 3 hours after each meal.
This should give you a better indication of what is going on, and if your current testing is missing a peak.

The other point is not all food reaches its peak 2 hrs after starting the meal. Some is faster and by 2 hrs you may have missed the highest point or some is slower (especially if there’s a lot of fat involved) and might take 3, 4 or even 5 hrs to reach its peak. That’s why even type 2 sometimes use the libre just a few times to get a better idea of trends. If only doing fingerpricks that’s a lot of pricks though! And not necessary for most foods and even when you do try extended testing each meal will only need it a couple of times to get a good idea of the results.

I share your frustration. I always think my next Hba1c will be lower, but without a cgm, my data recording is too sparse to represent averages. The most useful readings are my waking and bedtime. What I have come to realise is that if my wakings are glucose impaired (5.7 mmol/l - 6.9 mmol/l) my Hba1c ends up being glucose impaired (and a higher average than this - the last one I was averaging 7.3 mmol/l which is 6.3%). If my bedtime reading is greater than 6 mmol/l, I need a late night dog walk else my waking will be greater than 7 mmol/l. The daytime tests are just to see how I'm reacting to meals (before, 2 hours after, 3 hours after, 5 hours after, but I don't do these as much.) Good luck.

thaddydv said:

Thank u all who replied for your inputs
I’m going to do a few more tests in the day to see if there are spikes
Will update in the next few days
Thank u

Click to expand...

I think there is alot more than we all know. I have tested across so many glucose monitors my head is spinning. I have had 2 monitors track with surgery professional units calibrated with a hospital (one tracked perfectly, the other the same as yours was 0.1 higher). I also tested Libres over a 2 year period. In short all showed fbg's of between 3.8 and 4.4, pp's of around 5.6, never a reading of 6 or above. HBA1c's (Ipswich hospital) 38 mmol. Medichecks 35.5 mmol, A1CNow ÷ loads of tests around 31 mmol.

What matters for me is that I know I am not spiking and that I have seen numbers going down on the meters relative to where I started. I come from an alAfro Caribbean, so know there are confounders with the A1c test, and I naturally have a low white blood cell count which can interfere. In short I would ensure you concentrate on your relative performance to a tuned in meter (ask your surgery to test off the same sample of blood).

thaddydv said:

Thank u all who replied for your inputs
I’m going to do a few more tests in the day to see if there are spikes
Will update in the next few days
Thank u

Click to expand...

If you give us an idea of meals we might be able to give some ideas of what’s happening with them and when might be good to check them