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Variable meter readings

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velofan

Active Member
Messages
35
Type of diabetes
Prediabetes
Treatment type
Diet only
Having found I'm prediabetic, have been working on diet, weight, exercise etc, and have started taking fasting blood glucose readings in the morning pre-breakfast to creat a baseline to work from. I'm using an Accu-Chek Performa Nano. Recently, I've taken a trio of readings within a few minutes of each other to check consistency. The first set (a week ago) gave figures of 5.8/5.3/5.0, the second set, yesterday, gave readings of 5.6/5.6/4.9.

I appreciate that accuracy for these monitors is likely to be +/- 15%, but am surprised at the variation between the meter's own readings. Can anyone help with an explanation please.
 
Hi, @velofan , a lot of it is to do with the way meters work.

They're not like precision weighing scales, where you would expect the result to be the same.

The strip contains an enzyme, typically glucose oxidase, although there are others, which oxidizes glucose in the blood, breaking it down into hydrogen peroxide and a few other things, the chemical reaction gives off electrons, the meter measures those as an electric current - the higher the glucose, the higher the current - and then decides what that amount of current represents as bg.

There's a lot of flittery "guesstimation" going on in that situation, so it's best to regard any reading as a "ballpark" figure.

Your readings are all in the same general ballpark, so, even though they are different, you've got some reassurance they are all about 5 and not 3 or 8.

I'm T1, inject insulin, so numbers are quite important to me as they are the basis of dosing decisions, but I learned long ago, from having to visually assess colours on a bg strip against a chart on the side of the strip container that numbers after the decimal point don't matter.

Other reasons for the differences are that bg levels naturally move around all the time as it is not a static system, and even in a short spell of time, there is no reason why concentration of glucose will be evenly distributed around the body.
 
Thanks Scott, that's really helpful. I suspect, then, that I'm not really using the meter at it's best - it's more useful comparing things like before and after meals and checking what spikes etc.
 
velofan said:
I suspect, then, that I'm not really using the meter at it's best - it's more useful comparing things like before and after meals and checking what spikes etc.
Click to expand...
This the best way of using a meter...
 
velofan said:
Thanks Scott, that's really helpful. I suspect, then, that I'm not really using the meter at it's best - it's more useful comparing things like before and after meals and checking what spikes etc.
Click to expand...

Yes, that's a good way to go about it, seeing the overall patterns, identifying big differences in numbers, and figuring out ways to reduce those.

Modern meters are wonderful devices compared to what I started out with 30 years ago, but I think people can be misled by attaching too much weight to the number after the decimal - if you're looking for a broad indicator of whether your bg is 5 or 7, they are good, but newly dx'd have driven themselves mad fretting over whether they are 5.6 or 6.2, when those numbers are basically the same!
 
Don't forget too, that your blood is circulating, not static, which means the glucose it's carrying round is also going to vary too,especially from finger to finger.

Just use your meter to look for overall patterns & trends and don't be too bothered with repeat testing. The only time you might need to do this is if the reading you get is way out from what you expect and then it's worth washing hands in case of contamination and trying again. If it's still out, then start thinking about why.

Robbity
 
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