Completely different measurements within minutes on different fingers?

[confused1234x]

I have not been diagnosed with diabetes but I am worried about being prediabetic.

Back in October my fasting blood glucose was always low 5s and high 4s when I used to test.

Sometimes when I have checked my blood glucose lately with a different monitor I have seen figures like 6.1 or 5.9 fasting which has surprised me.

Whenever I have gone to check again because that is higher than usual and on the same finger it will then be '3.8' '4.4' '5.4' '5.1' just completely different numbers within minutes of eachother. I know glucose monitors can be out by a bit but this is a bit much.

One reading puts me in the prediabetic range the others put me in the normal. I've followed all precautions washing my hands not squeezing too much etc. and I can test each different finger and get a different result.

 

[Inka]

Have you had an HbA1C test done @confused1234x ? That might be useful if you’re concerned.

The meters do vary when they give readings. You’ll often get slightly different readings when you do consecutive tests. I think, from memory, they can vary up to 15%, or something like that.

 

[confused1234x]

@Inka I had one done about 3 years ago I think and that was all normal but no recent ones.

 

[Inka]

Ok - that’s good. So is there anything that’s made you worried you might be pre-diabetic now? Any symptoms?

 

[confused1234x]

@Inka Thankyou. My doctor prescribed me some antibiotics for a urine infection recently because I had some bladder pain and fullness but no urgency but I thought it could be linked to my sugar levels so I thought I'd do a one off fasting test. That came out higher than I've had before and it surprised me so I have been retesting. I have convinced myself that I have suddenly become prediabetic in 6 months, I haven't had readings that high before but then when I retest they are in a normal range so not sure if I should worry or not really.

 

[Inka]

Ah, that makes sense. I can see why your urine infection got you thinking about your blood sugar again. I think the best thing to do is to just keep an eye on things with an occasional test for your own peace of mind. If you continue to be worried (and I don’t think you need to be if your readings are normal) then I’d ask for another HbA1C test just to see how things are going as your last one was three years ago.

But what you’ve described sounds ok and nothing to worry about at the moment 🙂

(Speaking as someone with diabetes not as a medical person)

 

[Toucan]

Hello @confused1234x and welcome to the forum.
Meter reading can vary quite a lot particularly between different meters, and even between minutes of doing a tests.
Readings also depend on when you take them, relative to eating. It needs to be 2 hours after food.
The main indicator that I use is an early morning reading before eating or drinking.

Overall your readings look to be OK, and sometimes the stress caused by concern about reading can it itself put them up a bit.
As @Inka says, probably Ok to just test occasionally to keep an eye on things, and in the meantime try to eat a healthy diet and have a good level of exercise.

Best wishes, and please ask about any concerns you have, or just let us know how it is going.

 

[everydayupsanddowns]

It’s frustrating isnt it @confused1234x

Each meter has its own degree of variability (some are wobblier than others) and they are required to be more accurate in the lower range - so 15% variation at higher numbers, but (I think) more like 5% when you get down towards the 4-5s. However not all meters manage to hit this all the time, and all of the requirements are only required to be met 95% of the time.

In general terms it is worth remembering that
a) Blood is not entirely homogeneous. In different parts of the circulation system there will be slightly different concentrations
b) The decimal point accuracy is a bit of an illusion, home BG meters are a bit more ‘ish’ than that
c) Some meters give more variability than others. You may be using a ‘wobblier’ one
d) All meter instructions suggest that if a single reading doesn’t match how you are feeling you should check again - any strip might give you a duff number

There was an article comparing meter accuracy across different brands from a few years back that I will try to find again

Hope you can take more of a general picture and the limitations of the tech doesn’t cause you too much anxiety

 

[everydayupsanddowns]

This wasn’t the article I was thinking of, but it’s a clinical study from the US which compares accuracy across various meters and expresses them in Mean Absolute Relative Difference in % which ranges from a modest 5% to a much more significant 20% variation from lab values.

Comparative Accuracy of 17 Point-of-Care Glucose Meters - PMC

The accuracy of point-of-care blood glucose (BG) meters is important for the detection of dysglycemia, calculation of insulin doses, and the calibration of continuous glucose monitors. The objective of this study was to compare the accuracy of ...

www.ncbi.nlm.nih.gov

 

[confused1234x]

@everydayupsanddowns That is amazing thankyou I will have a read, really great advice I wasn't aware that metre readings could vary that much!

@Inka and @Toucan Thankyou for the response and reassurance.

 

[mikeyB]

None of your BG readings would remotely suggest diabetes or "pre diabetes". Your chance of developing diabetes is the same as everyone else in the world.

You should be made aware that a BG of 11 can be recorded in folk without diabetes after eating a Mars Bar with a full sugar Coke. Soon goes back to normal range. Try to stop testing, all you will discover is normal readings.

That said, if you think you are at risk because you are overweight, change that. Your risk will plummet.