Accu - Check Instant - wrong readings

[sgiossi]

Hello,
I use Accu-Check Instant to monitore my glucose. I don't have diabetes, but I had HbA1c results close to pre-diabetes level in the past, and some fasting glucose blood test borderline prediabetes in the morning.
I therefore decided to use Accu Check to see how my sugar levels fluctuate in my body when I eat, when I wake up etc in order to prevent HbA1c getting into the prediabetes or diabetes ranges. I'm 45.
What I've learnt is that generally I have glucuse meter results which are in the pre-diabetic field in the morning, let's say between 5.6 and 6.3%, This could be linked how my body works, but also to the fact that I eat around 7-8 PM and my glucose seems to reach a peak after 4-5 hours, especially when I eat carbs (not sugar). I believe this might be linked to slow digestion. I suffer from reflux and take lansoprazole.
If I eat earlier in the evening and just a limited amount of carbs, there is more time to digest before going to bed,and therefore the readings are below 5.6%, let's say 5.2/5.4%. My most recent HbA1c test was 5.6%, so within the normal range. In the last couple of years, HbA1c results were mostly around 5.3-5.4%, just once a bit higher, 5.9%. I take a HbA1c every six months roughly.
The Accu readings seem to be generally precise, sometimes matching the glucose lab tests that I took in the lab in the same morning.
However, in the last couple of weeks, I had a couple of strange readings.
- Once, I monitored my glucose with Accu at around 5 AM when I woke up, and the reading was was 7%. Although I ate really late and slept little, I was a bit surprised. It wasn't full fasting but still. I then decided to retake the test immediately and on the same finger, and the result was 5.2%. Then, just to double check, I took 3 readings over the next 15/30 minutes and they were all around 5%, within a normal range, actually lower than my usual ones. I know there can be a slight difference between fingers.
- Today, I monitored my glucose in the morning, at around 7 AM. I didn't eate a lot yesterday evening so I was surprised that my reading was 7%. I took several readings in the next few minutes on different fingers and they were all around 5.7%.
What is the reason as to why the glucose meter read incorrect values? The 7% was clearly incorrect both times.
Thank you

 

[Rokaab]

Some times test strips are just wrong
Also note with blood test meters they are considered accurate if within 15% of the actual value so if you were actually at 6mmol/l then anywhere between 5.1mmol/l and 6.9mmol/l would be considered accurate enough by the meters and for them not to be considered 'wrong'

 

[sgiossi]

Some times test strips are just wrong
Also note with blood test meters they are considered accurate if within 15% of the actual value so if you were actually at 6mmol/l then anywhere between 5.1mmol/l and 6.9mmol/l would be considered accurate enough by the meters and for them not to be considered 'wrong'

That's a huge range.

 

[Antje77]

That's a huge range.

It's not a huge range, although I completely agree it's annoying when results aren't correct.

Your accu check seems to use mmol/l for blood gluose, which most of us use.
You mention %, this is not the type of units your meter uses, your meter shows your blood glucose in mmol/l. Your hba1c can be measured in both % and mmol/mol, both being a different measurement from daily fingerpricks.

I understand that you're frustrated that a fingerprick of 6 mmol/l could mean anything between 5 and 7, but keep in mind that those devices were made with T1's in mind, and meant to catch highs of over 20 mmol/l and prevent dying from lows.

A meter is very useful to keep an eye on things, as you are doing, but please don't get too hung up on a single ouutlying number. Could be a dodgy teststrip, could be something on your finger.