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Bg monitor reliability / how to make sense

I

infinitemantra

Active Member
Messages
31
Type of diabetes
Type 2
Hi all
I was diagnosed in june this year h1ac 147 4 weeks ago down to 47. i have been low carbing for about 8-10 weeks now. until recently i was assuming that my monitor was consistant if not correct and that over time i woild be able to make a rough guess as to how it related to the h1ac scores (higher lower or similar taking into account when i test).

However i have recently had some result i didn't expect so i re tested and found quite variable results. the most recent example being 1 hour after bacon. first result 10.4 then a minute later 8.1 then 30 secs later 7.3. this makes me a bit unsure as to what the monitor is telling me. in this instance it is tempting to dismiss the 10.4 as unlikely, but what if lots of the tests that i do every day are as off as by 3 mmols? this makes the difference bwtween an ok spoke of 8 or a bad spike of 11 or a good fasting of 5 or a pretty bad one of 8.

So far testing ( quite frequently) has given me a feeling of being in control and that i am gaining knowledge, i am now doubting this. I will continue to test anyway just with less faith in the results.

has anyone any thoughts experience or advice?

Thanks

some details.

freestyle optium give to me by doctors

prescription strips supplemented by internet ( seem exactly the same)

test about 5-8 per day mainly to see waking levels and find when and how high spiking.

haven't bothered cleaning hands before testing

haven't been changing needles often
 
I suggest you clean/wash your hands before testing, there are various skin contaminants that can affect bg test results and which might vary from test to test.
 
I have read on other threads people saying dont worry about the actual figures just the rises after meals. but how can you see a rise after a meal if the monitor gives variable results to the degree in the example.

for example my morning was 6.2. but what if i had taken it again and it had been 7.5 or 5?
then my post bacon readongs of 7.3, 8.1, 10.4 could have been a rise of up to 5.4 or even a slight fall.
 
I think it's important to note that glucose readings, from the same drop of blood, different test strip, temperature of your fingers, can vary. Also, two different meters/test strips can give differing results

It's best to wash your hands before testing, to be sure there is no food stuffs, grease or any other whatever, is on your fingers. Many don't change the lancet needle too often. Again, that varies. I usually use a new lancet daily but others may use theirs longer before changing.

Another thing, it's a good idea to test immediately before you eat so that you have a 'base line' to compare your post-meal test
 
I'll second the clean hands, especially after preparing and/or handling food.

I posted this on a different thread yesterday, but I'll post it again as it highlights the possible error margins for meters. The differences in values from tests done at the same time, can vary quite a bit:

http://www.diabetes.co.uk/blood-glucose-meters/blood-glucose-meter-accuracy.html

You probably don't need to, but you can always test your meter with a control solution. You'll be able to get this from the manufacturer if need be.
 
thanks for the replies. the meter accuracy link particularly.
so wash hands
use meter accuracy table to make guess as to actual blood based on three readings e.g if meter is accurate then cant read 7 and 10 so readind must be 8 or 9.

but does mean need to take all readings with a pinch of salt unless re test.

dony get the advice to test before meals to get basline. As i give in my example if both before and after can vary as much as shown in the table supplied by grantgam you cant easily see whether you have spiked a little a lot or not at all.
 
infinitemantra said:
thanks for the replies. the meter accuracy link particularly.
so wash hands
use meter accuracy table to make guess as to actual blood based on three readings e.g if meter is accurate then cant read 7 and 10 so readind must be 8 or 9.

but does mean need to take all readings with a pinch of salt unless re test.

dony get the advice to test before meals to get basline. As i give in my example if both before and after can vary as much as shown in the table supplied by grantgam you cant easily see whether you have spiked a little a lot or not at all.
Click to expand...
There's no need for you to take 3 readings just to get an average. The table just shows you the range where your BG should be 95% of the time. Testing that much would cost a lot and give you sore fingers!

The important thing with a BG meter is to spot trends with your blood glucose readings. Ideally, you should just try and keep them as low as possible:)
 
You will get varied readings because (a) your blood (and so the glucose in it) is circulating all the time and (b) your glucose levels are too. So it's not normally a meter issue. However if you do get any "odd" result then (re)wash hands and test again, and also have a think about any possible causes for it.

You definitely need to test immediately pre-meal to get a base level and shouldn't worry too much over individual figures, just keep records and watch for watch for trends and patterns. The pre-meal test is the specific start point for that meal and you can see from 1 and 2 hour post meal checks what kind of spike you get and how quickly your levels come back down again after eating that particular food (or combination).

Robbity
 
Meter inaccuracies aside, it is very difficult to anticipate an HbA1c result. Much depends on your personal rate of glycation and your red blood cells. Some people will always have a higher A1c than expected and others will always have a lower A1c than expected. Even people with CGMs find this. Also you would need to finger prick every 10 minutes or so, 24/7, to get a decent average.
 
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