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Difference in readings between freestyle liner and blood glucose monitor

L

Leeannea

Well-Known Member
Messages
131
Type of diabetes
LADA
Hi. I have LADA and am on novorapid and lantus . I just got a freestyle libre in an effort to fix my terrible waking to lunchtime readings. I know that the libre tests interstitial fluid and that there is a 10 minute lag time between that and blood but there is a 20% difference between the libre and glucometer, with the former consistently higher, even when I've been sitting and not eating. I had faith in my glucometer with regard to the amount of insulin I injected but I also trust this new technology but I'm scared of having a hypo if I inject according to its readings. Can anyone help. Many thanks
 
Hi and welcome.
I can't advise you on insulin doses but my experience of the Libre is that each sensor tends to be consistent to itself. Then the next sensor will be consistent to itself. Mine usually read lower than my prick tests. So you may feel confident using the sensor for tends and indication of rises and falls, then use the prick test for actual doses.

Having said that, if your sensor is more than +/- 15% of your prick tests, then you can give Abbott a call. Posters have reported that Abbott have replaced the sensor in these circumstances.
 
The recommendation I was given was to always judge your insulin dose on a finger prick.
I know not everyone follows the advice.
However, we I trialled the Libre (twice), I found the values so different (and not consistently) from my finger prick, the only value I got from it was the trend arrows.
Others find it great but when a Libre reading of 4.0 could be anything from 2.4 to 4.8 and a Libre reading of 12.0 could be anything from 10.0 to 15.0 (in my experience), I decided it was not for me.
I did realise my BG change quickly when I am exercising and the Libre is reported to work less well in these conditions.
 
I was running two meters for a time to get a high degree of accuracy, and I found both meters did not register the same reading. I began to match my symptoms to the meter reading to determine the most accurate reading. I have now adopted the Accu-chek performa for its accuracy.
 
I tend to see similar to @Brunneria - my sensors have generally and consistently read lower than my Contour Next meter; they do show me the same trends/patterns as my meter readings though, and these are what I'm specifically interested in when using one. I'm T2/pre-diabetic and on diet only so perfect accuracy isn't so critical for me, but I would definitely always do a finger prick test to confirm my BG level if I was relying on insulin and seeing the up or down arrows on the sensor readings suggesting that I was going too low - or high.

If I remember rightly from other threads, for replacements due to inaccurate readings, Abbot would ask for confirmation readings via finger prick tests done with the Libre reader (or possibly one of their other meters?). The reader takes Freestyle Optium test strips.

Robbity
 

Thank you so much for replying and with such good help. I'm very grateful. I will ring today as my fbg on my glucometer was 6.5 and 9.4 on my libre.
Cheers
Leeanne
 

Thanks so much for your input. It's reassuring to know that it's just not me cheers
Leeanne
 

Hi. That's an excellent idea as I have a backup glucometer . I'll do that from this a.m .This forum is so helpful!
Kind regards
Leeanne
 

Thanks for your help. I didn't use the glucometer on the libre so that's good to know.
Cheers
Leeanne
 
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