Blood glucose monitor readings and their accuracy?

[markpj31]

Hi,

I was put on insulin in January this year after 11 years of oral meds. I was working alongside the diabetic nursing team, trying to find the dose that was for me, starting at very low amounts of insulin and working upward. My readings seemed to be all over the place with what seemed like mainly highs at first, going all the way up to 18 and generally waking high (10+) and going to bed high.

I recently went for my actual blood test (HbA1c) in May which turned out to be 48 mmol/mol (6.5%).

Anybody else noticing that their actual HbA1c results are not really being reflected on the averages over the months of the blood glucose monitors?

 

[sallymac65]

Welcome to living with Type 1 D. From my experience, the results are often more accurate than how you feel. It's in our nature to remember the bad, not the good bits. 6.5 is really good, you should be proud of that

The problem with this disease whichever flavour is that you can very quickly if you're not careful to become a diabetes geek and seriously who wants to be with one of those and enjoy spending time with them if all they are concerned about our where their BGs are. Let it do its thing and you do yours.

Life is for living after all! Chin up

 

[Antje77]

Anybody else noticing that their actual HbA1c results are not really being reflected on the averages over the months of the blood glucose monitors?

Have you been checked for aneamia?

 

[jape]

@markpj31 - I have come to accept that the average a1c from my BG meter is lower than what I get from the vampires (blood testing service). The difference is about 0.8%. Yes, it does take some time to find the right insulin dosage. One's BG level is a complex dynamic between the foods one consumes and insulin, not always completely predictable.

@Antje77 - interesting that you mention anemia. I am borderline anemic, and will certainly investigate that further. Thanks. I have some issues my a number of Libre sensors last week (one - applicator got jammed, two - blood was streaming from my arm,and the showing I am hypo, that was not true, three - a sensor that showed a difference of about 4 points from my finger blood). They were all replaced by Abbot. The representative from Abbott asked me whether I have been taking aspirin - which I have done daily for the last 25 years. Something new to me as well.

 

[Daibell]

Hi. All glucose meters have to meet an accuracy of +/- 15%. The HBA1C is usually pretty reliable but my last one was suspect compared with my Libre 2 and my history. If you are T2 with any excess weight it's possible you already have too much insulin in the body and having insulin shots could give unpredictable results. If you are slim then it may well help. A lot depends on whether you have any insulin resistance.

 

[Deleted member 543160]

Something to be aware of with HbA1c tests is that they are an average over three months. and it's possible for those averages to give the same end result from either fairly stable glucose levels or totally erratic spikey ones.

My feelings are that using Libre sensors for a while can be useful to discover actual glucose patterns - as you see what's going on 24/7; however when I used them for a time, my sensors always gave me rather lower results overall than my finger pricks.

So, my HbA1c checks have been a little higher than predicted results from my meter tests and rather more than from sensor predictions. But the overall patterns/trends I've seen between regular finger pricks. sensor scans/predictions, and actual HbA1C checks have always been quite consistent in their patterns - just with three slightly different levels.

 

[markpj31]

Have you been checked for aneamia?

Apologies for the late reply.

I assume that would come up in the full blood count part if of the blood test? I don't have any symptoms of it as far as I can tell.

 

[markpj31]

Something to be aware of with HbA1c tests is that they are an average over three months. and it's possible for those averages to give the same end result from either fairly stable glucose levels or totally erratic spikey ones..

That is a very good point, and I would suspect that bouncing from say a 3mmol/l to say a 11 in one day on a regular basis would be pretty destructive. Yet, may well not be reflected in the HbA1c result. I tend to keep my numbers between 5-7 during the day, but my waking BG seems to be the bit I can't control.

 

[Antje77]

I assume that would come up in the full blood count part if of the blood test?

I have no idea to be honest. But it's one of the reasons a hba1c can be wrong.

 

[markpj31]

I have no idea to be honest. But it's one of the reasons a hba1c can be wrong.

Interesting. I didn't know that so thank you for the information.
I'll have to get my mother to get a print off of her blood test as she was found to have anaemia, and whether or not it is detected in the FBC/CBC part, or if it has to be requested specifically by the doctor from the labs.