Libre 2 issues

[gb350]

I'm type 1 for over 40 years now and a fairly latecomer to cgm tech.
I've been using a Libre 2 sensor for around 2 years now and I'm happy to embrace new technology when it is of benefit to me.
Since starting on the cgm journey I've had about an 80% success rate with sensors working at all which given the cost of these things is not great.
My biggest bugbear however is the accuracy of them. I've conducted a side by side test in the last few days with my contour next one finger prick meter.
This contour meter is without doubt one of the most reliable bits of kit I've ever had . It gives results which coincide with how I'm feeling at that particular time.
The results of my small experiment were not favourable for the Libre 2 sensor.
In a nutshell, my sensor measures on average at least 1mmol/L above at the top end and 1mmol/L below at the bottom end.
For anyone who is concerned about their time in range it's a gamechanger. You start with a 6 point window between 3.9 and 10 mmol/L , which is now reduced by 33.33333% to a 4 point window which stretches from 4.9 to 9.0 mmol/L.
Life is hard enough without having your margins squeezed to this extent.
Maybe it's just me? I don't know, which is why I'm putting this out there.
Before anyone starts on about the arrows and direction of travel, don't bother. My sensor can't even predict these with any accuracy.
I also learned about compression lows today. That was an eye opener. The things they neglect to tell you eh!
As far as I'm concerned, hitting time in range targets using a libre 2 sensor is akin to a Stevie Wonder hole in one at Gleneagles.
Thoughts please.

 

[Antje77]

Since starting on the cgm journey I've had about an 80% success rate with sensors working at all which given the cost of these things is not great.

I hope you contacted Abbott for every failing sensor, they usually replace without issue. In the case of a sensor failure halfway through a sensor it even means you get some extra days because they'll send you 14 days worth of new sensor even if the old one failed at 13 days.

The results of my small experiment were not favourable for the Libre 2 sensor.
In a nutshell, my sensor measures on average at least 1mmol/L above at the top end and 1mmol/L below at the bottom end.

Using alternative apps like DiaBox can be helpful because they can be calibrated.
My sensors consistently read lower than a fingerprick by 0.8 to 2 mmol/l (and have done so for the 8 years of using Libre). Thankfully my endo is happy to use the calibrated TIR from DiaBox on my official notes.

 

[TooSweetForMe]

@Antje77 can you use DiaBox with a Dexcom G7 or is it just for use with the Freestyle Libre?

 

[Antje77]

@Antje77 can you use DiaBox with a Dexcom G7 or is it just for use with the Freestyle Libre?

DiaBox can only be used with Libre as far as I know.
I know there are alternative apps for other sensors as well but I'm not familiar with them at all because I've only used Libre.

Google tells me the G7 can be calibrated, does this not work well for you?

Can I calibrate* Dexcom G7? | Dexcom

You can log a BG meter value as an event, or use a BG meter value as a calibration within the G7 App on your smart device or on the receiver.

www.dexcom.com

 

[TooSweetForMe]

DiaBox can only be used with Libre as far as I know.
I know there are alternative apps for other sensors as well but I'm not familiar with them at all because I've only used Libre.

Google tells me the G7 can be calibrated, does this not work well for you?

Can I calibrate* Dexcom G7? | Dexcom

You can log a BG meter value as an event, or use a BG meter value as a calibration within the G7 App on your smart device or on the receiver.

www.dexcom.com

I've only had my G7 for about a week, never really thought about calibrating. I'll go read that link. Thanks!

 

[Antje77]

I've only had my G7 for about a week, never really thought about calibrating. I'll go read that link. Thanks!

If you only had your G7 for a week, I'd take your time getting aqcuainted with it and it's perks before even thinking about calibrating.
Any particular reason you asked about using it with DiaBox?

 

[TooSweetForMe]

If you only had your G7 for a week, I'd take your time getting aqcuainted with it and it's perks before even thinking about calibrating.
Any particular reason you asked about using it with DiaBox?

I was just curious, that's all.

 

[Antje77]

I was just curious, that's all.

Curious is good, staying curious is the best way to learn about our condition and how to best manage it in my opinion!
If you have any questions or experiences to share with your Dexcom, please post.

 

[TooSweetForMe]

Curious is good, staying curious is the best way to learn about our condition and how to best manage it in my opinion!
If you have any questions or experiences to share with your Dexcom, please post.

I certainly will.

 

[gb350]

Thankyou for the responses.
I always return faulty sensors to abbott.
In fairness to them they do send replacements very quickly. I personally don't think getting a quick replacement is the problem here. The unreliability and inaccuracy of the product is my issue.
I am grateful for the Diabox tip-off and will definitely look into their app. Being able to calibrate the sensor seems like a ridiculously sensible thing to do.
So sensible, that you would have thought the manufacturer would enable it through their own software, rather than have people relying on a third party.
I'm able to shift the parameters on my Contour next one app and have moved the low bar down to 3 mmol/L , a level which works fine for me. I can happily test myself 50 times a week with green lights all the way.
In the testing experiment mentioned in my original post I did 12 side by side tests.
The Contour next one meter gave me 12 results in range.
The Libre 2 sensor gave me 7 in range and 5 out of range.
I don't find that acceptable at all.
Last night I retired to bed at around 10.30 pm with a reading of 5.8mmol/L on my sensor having eaten a moderately mid carb meal of steak, chips and salad at 6pm and dosed accordingly.
According to my Libre 2 sensor my BG level dropped into the red at 1am and bobbled along at around 3mmol/L until 6am.
When I got up at 7am it was showing 7mmol/L.
Is this unusual? No.
This is a regular occurrence.
Compression low? Who knows. I was absolutely fine this morning with zero ill effects from apparently being hypoglycaemic all night.
One side by side test today at 2pm, which had meter reading of 7.8mmol/L and a Libre 2 reading of 10.7mmol/L with a diagonally up arrow indicated.
Thanks to Antje77 for acknowledging I'm not the only one trying their best with bad data.

 

[Ushthetaff]

My experience with the libre is positive I know that it’s never going to be same as a finger prick this was explained explained during my training course. I don’t worry if there is 1 point of a difference as to be honest it’s . I keep my range between 5 and 9 if my reading is 9 i finger prick some people e go chop keep their range much tighter , my time in range is at 82 % plus my Hb1ac is between 48 -52 which considering I m on dialysis I’m told is very good plus I rarely have hypos anymore due to the low alarm settings I know everyone’s experiences are different but I would definitely rather have it than not as I can remember no personal blood sugar meters when my Hb1ac was above 95

 

[SimonP78]

I've also had a history of problems with libre2 sensors: https://forum.diabetes.org.uk/boards/threads/cgm-log-how-long-do-they-last-why-do-they-fail.114108

I think quite a lot of the problem is that I don't have much of an area on my arms into which to stick the device as I don't have much excess fat, so sometimes it works, sometimes it doesn't.

I use XDrip+ (via Juggluco which actually talks to the sensor, I don't use XDrip+ to do that directly) which also allows me to calibrate the sensors if they are off, though even that eventually runs into limitations (if the sensor will be off-scale low before the calibrated hypo value, which means hypo alerts can't be triggered - at this point I also send them back for replacement if they have more than a few days left on them)

 

[Jaylee]

I'm type 1 for over 40 years now and a fairly latecomer to cgm tech.
I've been using a Libre 2 sensor for around 2 years now and I'm happy to embrace new technology when it is of benefit to me.
Since starting on the cgm journey I've had about an 80% success rate with sensors working at all which given the cost of these things is not great.
My biggest bugbear however is the accuracy of them. I've conducted a side by side test in the last few days with my contour next one finger prick meter.
This contour meter is without doubt one of the most reliable bits of kit I've ever had . It gives results which coincide with how I'm feeling at that particular time.
The results of my small experiment were not favourable for the Libre 2 sensor.
In a nutshell, my sensor measures on average at least 1mmol/L above at the top end and 1mmol/L below at the bottom end.
For anyone who is concerned about their time in range it's a gamechanger. You start with a 6 point window between 3.9 and 10 mmol/L , which is now reduced by 33.33333% to a 4 point window which stretches from 4.9 to 9.0 mmol/L.
Life is hard enough without having your margins squeezed to this extent.
Maybe it's just me? I don't know, which is why I'm putting this out there.
Before anyone starts on about the arrows and direction of travel, don't bother. My sensor can't even predict these with any accuracy.
I also learned about compression lows today. That was an eye opener. The things they neglect to tell you eh!
As far as I'm concerned, hitting time in range targets using a libre 2 sensor is akin to a Stevie Wonder hole in one at Gleneagles.
Thoughts please.

Hi,

What I’ve found with the algorythm of the L2 is it can be ahead of the meter on a BG decent & a little behind on a rise?
Even slower coming out of a low..

On a relatively straight line? It’s close to about 0.6mmol with the meter for me..
As sensor reads interstitial fluid. From what I can understand interstitial fluid is the last inline for recovering blood glucose from a low with the brain taking priority?

Staying suitably hydrated helps with a more reliable reading, too..

 

[gb350]

My experience with the libre is positive I know that it’s never going to be same as a finger prick this was explained explained during my training course. I don’t worry if there is 1 point of a difference as to be honest it’s . I keep my range between 5 and 9 if my reading is 9 i finger prick some people e go chop keep their range much tighter , my time in range is at 82 % plus my Hb1ac is between 48 -52 which considering I m on dialysis I’m told is very good plus I rarely have hypos anymore due to the low alarm settings I know everyone’s experiences are different but I would definitely rather have it than not as I can remember no personal blood sugar meters when my Hb1ac was above 95

Well done to you for keeping control to that extent whilst on dialysis.
I think I was issued one of the first glucose meters in the UK back in 1978.
The Glucometer I think it was called. T'was a long time ago. Took a minute or so to get a result out of it and quite a lot of blood after physically sticking a needle in your finger. Had a lovely red LED display as well.
The days of glass reusable syringes and 20mm needles are etched on my memory also.
We've thankfully moved on a fair way from those days, but not enough as far as I'm concerned.
I would expect new tech introduced to the market to improve our lives, considering the investment and price point involved here.
For me with Libre 2 this just isn't the case.
Back in the halcyon days of the 90's I tossed my meter in the bin and didn't test myself for over 2 years. I relied instead on tuning myself into my body and adjusted insulin and food intake according to how I felt.
Worked pretty well, but I was then sucked back in to the testing regime with the promises of better technology and better control.
My Hba1c results are still bouncing around between 47 and 50 as they always have..
Fair play to you for getting a training course for Libre sensors.
I've never ever had the benefit of a mythical to me diabetic team behind me.
Apart from one decent consultant at my local hospital who I encountered 3 years ago, I've been on my own with this for over 40 yrs.
My GP is only interested in injecting toxins into me or a backhander for signing me up for statins.
Good luck with with your dialysis.
I'm recently out of hospital with stage 2 AKI , pancreatitis and renal tubular acidosis.
All good and looking forward to Spring.

 

[gb350]

Hi,

What I’ve found with the algorythm of the L2 is it can be ahead of the meter on a BG decent & a little behind on a rise?
Even slower coming out of a low..

On a relatively straight line? It’s close to about 0.6mmol with the meter for me..
As sensor reads interstitial fluid. From what I can understand interstitial fluid is the last inline for recovering blood glucose from a low with the brain taking priority?

Staying suitably hydrated helps with a more reliable reading, too..

I'd 100% agree with that. In the mid range it's not tragically bad.
At the low end it takes forever to pick back up again.
This for me has meant several hours sitting in supermarket car parks waiting for my ****** sensor to catch up with reality.
5 to drive and all that.
Could anyone explain to me why a sensor which goes deeper into your arm than a lancet penetrates your finger should be measuring different types of blood.

 

[Jaylee]

I'd 100% agree with that. In the mid range it's not tragically bad.
At the low end it takes forever to pick back up again.
This for me has meant several hours sitting in supermarket car parks waiting for my ****** sensor to catch up with reality.
5 to drive and all that.
Could anyone explain to me why a sensor which goes deeper into your arm than a lancet penetrates your finger should be measuring different types of blood.

Hi again,

5 to dive? As far as I’m concerned. My brain says I’m fine when fit to drive. I’m lucky enough to not feel anywhere near confident to operate a digital watch or the flys on my trousers. if I feel low symptoms. I carry my meter in my van to legally confirm.
The meter will prove the fact I’m back to cognative function regardless of the lag in the sensor…

The depth of the sensor; I can only surmise it needs to hit the interstitial fluid layer under the skin to do its job?
Where as a puncture wound with a lancet is needed to draw enough blood for a meter.