Difference between libre and finger prick

Smiter55

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I am having a bad day with blood glucose high warnings from my libre reading 16.2. Did a finger prick and it's showing 18.5. I'm t2. Had my glimepiride and not had anything unusual to eat. Don't have a team as such. My gp and one of the nurses at the surgery when i can get through..

Question is which reading do I use? Libre and finger pricks have always been around the same till now.

My glucometer recommends I repeat fingerprint in 4 hours. Anyone got advice on ways to bring it down?
 

In Response

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3,488
Type of diabetes
Type 1
Treatment type
Pump
Finger pricks are always considered more accurate that CGM.
This is especially true when your levels are high or low as CGMs are calibrated to be most accurate at "normal" levels which will be why you are currently seeing the difference .
 

Smiter55

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It's dropped to 6.3. Just in time for lunch mug of home made soup, which is just Turkey stock and meat with carrots and parsnips.
Screenshot_20221229_140142.jpg
 
D

Deleted member 564899

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Finger pricks are always considered more accurate that CGM.
This is especially true when your levels are high or low as CGMs are calibrated to be most accurate at "normal" levels which will be why you are currently seeing the difference .
Interesting to know that- as I started on Libre2 a month ago and the readings are very high even when I've stuck to a good eating plan. I'm having to eat very little to stay under the 20's. :confused:
 

HSSS

Expert
Messages
7,476
Type of diabetes
Type 2
Treatment type
Diet only
What was breakfast (including drinks)? Or did anything else occur around that time? What time did you take your medication?
 

Smiter55

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What was breakfast (including drinks)? Or did anything else occur around that time? What time did you take your medication?
Same as I often have, one slice buttered wholegrain toast,mug of coffee at around 10.30. Meds taken at usual time diabetes meds only my glimepiride before breakfast. Other meds after but all for heart and other stuff. Eye appointment at hospital but nothing I was worried about. Been having stupid highs for months gp increased my glimepiride to one begore evening meal but stopped that because I was having serious lows during the night. I have spikes for no apparent reason. I've asked for a review but like everything nhs got to wait.
Screenshot_20221228_085455.jpg
 

HSSS

Expert
Messages
7,476
Type of diabetes
Type 2
Treatment type
Diet only
Tbh the variance between liber and fingerprick at high levels isn’t that surprising, nor is their being closer in normal level range. What is concerning is the size of the rise at breakfast, and other meals looking at the weekly summary graph. You are high pretty much all day only approaching normal levels at night.

As a type 2 the problem is inability to cope with carbs/glucose. And the fact that our insulin doesn’t work well despite typically being quite high (your medication increases how much you make to try and overcome this with yet more insulin). Unfortunately high insulin levels make us more resistant to its effects, causing the ever decreasing circles with control. Sometimes after years of this we actually then produce less insulin and an actual deficiency is added to the problems.

Do you restrict carbs at all? Or just sugar itself? If you’re not restricting all types of carbs that might be the issue here. For instance the bread you had a breakfast would cause a significant rise for a lot of us. Depending on what you have for breakfast, lunch and dinner lowering carbs might help. The danger, if you are eating a lot of carbs, is you are on a level of medications that is catering for the high daytime levels that will also mean lows overnight if you aren’t topping up carbs constantly and I can see from your earlier posts this is an issue for you. Perhaps starting with changing breakfast is the safest option to see what diet changes do to your early part of the day levels without risking the overnight issues. If it works you might be able to lower both carbs and medication across the board and as a result have better levels and fewer low points overnight.
 

Smiter55

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Messages
63
Thani you for your input.

Different days different foods. For example today, scrambled egg and bacon with a cup of tea. Max carbs in a day are around 80g. I avoid refined carbs and try to stick to low gi. I eat 3 meals a day which avg 20g carbs and sometimes couple of snacks. I'm not perfect, I eat the occasional pack of crisps. I know there is a train of thought that cutting out carbs is the way to go, however my gp etc frown on that and advise under 100g a day. I avoid sugar like the plague, one square of chocolate makes me sweat and feel ill.

I have a telephone consultation again on 5th. I just wish my surgery had libreview, would be so much easier than trying to explain the graphs.