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Continuous Glucose Monitor vs Blood Glucose Monitor

N

nanabon

Member
Messages
20
Type of diabetes
Type 2
Treatment type
Tablets (oral)
Hi All,
I just purchased a Libre Freestyle 2 and have had it about a day. The readings I am getting are about 4-5 points higher than my Safe AQ blood sugar monitor. For example: CGM says 11.9 and BSM says 7.7. Any thoughts? I thought this would be good as on fasting days my fingers get thrashed as I check every 2 hours to be sure I am not going too low but now I am concerned that one of them is wrong. Been using the BSM for about 3 years and trusted it's readings but newer tech is making me wonder which I should trust. Any advice would be great. Thanks all
 
I know a lot of people on the forum have said it takes 24 hrs for the sensor to settle down , I have done this from day 1 and have had the Libre about three months and the readings are not to different to the finger prick most of the time but have been up to 4 out on the odd occasion .
 
If you are diet only (no hypoglycaemic medications) why do you think you will go too low? Are you type 2?

All humans have a regulation system by which the liver dumps glucose into the blood if levels drop below norma, bringing it back up. It’s only usually medications like insulin or those that make your body make more insulin or some fairly rare medical conditions that cause worrying hypos. So fundementally our risk as diet controlled type 2 is the same as any non diabetic, ie pretty darned small.

How often are you fasting? I’m assuming it’s not constant. And fingerpricking should usually hurt if you’re doing it right. Minimal lancet depth, don’t press it hard against your finger, don’t squeeze the tip to get blood out, have warm dry hands massaged before the prick, aim for the edges not the centre or tip of the fingerprint. All in all if you don’t settle with the cgm then you should hopefully be able to improve your meter testing situation.
 
CGMs like Libre are excellent pieces of kit but only if you understand the limitation.
Sadly, Abbott do not share these limitations. However, it does not take much effort to find teh many many many many times they have been mentioned on forums like this one.
 
I am taking some some herbals as I did not get along with Metformin (insulin plant - makes your body make more insulin and berberine). Also, I am taking dapagliflozin and semaglutide. I get the liver glycogen thing and am aware that my blood glucose could be higher on fast days (2 x 36 hour water fasts in a week) because of that. As I said, been using my BGM for 3 years or so, pretty sure I've been using it correctly. It's the Libre Freestyle 2 that is new and I just wanted to see if others had experienced a variation between CGM and BGM in the readings.
 
Ah that makes a difference (your profile previously said diet only hence my comment). Hopefully you are aware of the risks of euglycemic DKA (dangerously high ketones even whilst blood glucose isn’t exceptionally high) when taking flozins and limiting carbs a lot - as you would be doing whilst fasting

I’m not saying you are doing anything wrong, but some people do it in ways that cause extra pain for years and it’s always worth checking.
 
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