The Libre, am I missing the point?

A lot of people have found that they become more accurate as time goes on - once the immune system stops reacting to the intrusion of the filament. I apply a new one 12-24 hours before the old one expires, and then activate it once the old one has expired. This give time for the inflammatory response to recede, and then you’ll get more accurate readings. I’m on my sixth sensor now, and it’s as accurate as my blood meter - I feel confident enough to bolus from it and now only blood test while driving.

Thrill said:

Hi all,

After seeing this place littered with the words 'Libre', I went ahead and ordered the kit. It arrived and the sensors now in my arm but I'm confused about what all the fuss is about and I'm also worried I'm missing something or using it incorrectly.

After a few days using it I'm doing twice the work as I'm checking my BG with a finger test more than usual vs trusting the Libre. I appreciate it's not blood and isn't as accurate but it's worryingly inaccurate. One scan will be 10+ MMOL the next will be 4.5 within 15 minutes. I have zero faith in the device a few days in.

I'm confused because all I see at the moment is a poor quality (the reader is awfully tacky!) overpriced monitoring solution. The graphs are cool but the sensors are that inaccurate, I may as well not waste my time looking at them.

Please enlighten me somebody! One half of is ready to send it back and getting a refund, but the other half wants to make the most out of it.

Thanks all. Don't take this is a nag, it's purely my initial thoughts of using the Libre after excitedly waiting weeks for it. I feel a tad let down.

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What value did the finger prick test return when you got those readings from the Libre?

Mel dCP said:

A lot of people have found that they become more accurate as time goes on - once the immune system stops reacting to the intrusion of the filament. I apply a new one 12-24 hours before the old one expires, and then activate it once the old one has expired. This give time for the inflammatory response to recede, and then you’ll get more accurate readings. I’m on my sixth sensor now, and it’s as accurate as my blood meter - I feel confident enough to bolus from it and now only blood test while driving.

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Do you mean that accuracy improves after one has been using the system for, say, six to eight weeks? Or do you mean it just takes time for each sensor to 'bed in'? I've recently got the system, and my first sensor is on day 12. It's still nowhere near as accurate as fingersticks for me yet...

Maybe some of us react different, but I found the Libre grossly inaccurate to the point of being useless. I gave it 3 or 4 chances and it had me in hypo territory many times; if the readings were accurate I would have been cured of Type 2. Genuine good luck to anyone else using this device, maybe they need a calibration mechanism that can be stored within the app.

Colin of Kent said:

Do you mean that accuracy improves after one has been using the system for, say, six to eight weeks? Or do you mean it just takes time for each sensor to 'bed in'? I've recently got the system, and my first sensor is on day 12. It's still nowhere near as accurate as fingersticks for me yet...

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From what I’ve read, the first sensor or two seem to be less accurate and then your body sort of gets used to them, so doesn’t seem to attack the filament. Mine is within 1mmol of my blood meter today, I only activated it this morning.

For all those people who think the libre is widely unreliable because it doesn't match up with their blood meter I wonder how many have tested a drop of blood then squeezed out another drop and taken another reading or used a different meter and different test strip?

If you do you might decide your blood meters are pretty unreliable as well and then that becomes scary as you no longer know what to trust. If you use the libre you have to have a reasonable amount of faith in it. There will be times though when a libre sensor may not perform as it it is wise to test bloods from time to time if in doubt and in the first few days.

The longer you can leave the libre in before activitating it the better in my experience. Having waited 4 weeks for our last libre delivery and with my son having run out several days previous the libre was inserted and started up immediately. For a good 6 hours afterwards it was reading 2 - 3 below our blood testing and spent the majority of the time saying low whereas blood were generally between 4.5-6. By morning it was reading a figure and much more in line with blood readings.

If I can…
All the stuff measuring glycaemia in interstitial fluids is far from being accurate, it's undoubtable.
But all them give the basics on which to work to obtain a real continuous sugar monitoring, and this happens applying a Bluetooth transmitter over the sensor, connecting it to a smartphone or smartwatch using XDrip+ APP.
All this together allows the full calibration of the sensor, obtaining corrected values that are very close or equal to the glucometer ones.
I use FreeStyle Libre from 15 months, with many of the same problems almost all the Libre users have, but from 6 months I have a Bluetooth transmitter over the sensor, and my life changed 180°.
Now I make three blood tests a day at worst, if the sensor readings are far from the blood values, otherwise only one, before sleeping.
This gives me the possibility to have a safe sleep, without the fear of a sudden hypoglycemic coma during the night, thing that occurred me eleven times in my 57 years of type 1 diabetes.
And this, believe me, is a real improvement in my life.
Just a suggestion.
Bye.
Pippo

I believe that the Libre is best used as a learning tool looking at the BG graph alongside the details of all the food/drink you have had and the insulin used. It may not gives an accurate BG reading as a normal meter, but it does tell you how much your BG has changed and how fast it is changing.

There is also the possibility you have a bad sensor, phone them up and ask for help if the readings still don't make sense once you have had the sensor in for a few days. I understand that people are often sent free replacement sensor.

Based on my own experience and after reading a lot about the Libre:

• Quite a large proportion of sensors are just faulty (it could be up to 20-30%)
• Abbots replaces those free of charge very quickly after a phone call (replacement received next day, despite low stock)
• Body takes time to get used to sensor. Best to wait at least 24 hours between placing it and activation
• Make sure not to move or bump the sensor once placed
• Don't cover the whole sensor/hole with plaster or similar
• Avoid vitamin C
• Libre is more about trends than actual values/measurements
• It's useful to see the reaction to specific food after eating (i.e. spikes after 60 minutes) or what's happening during sleeping or exercise
• A blood sugar tester is more accurate/reliable to do a specific spot check

The game-changer is that you can now finally check your values as often as you want in any situation without the need for a kit, ruining your fingers, cleaning up your fingers and getting rid of strips. This includes seeing the actual curve caused by what you just ate to better understand how much you need to inject and when for the next time. Before I got mine, it was easy to ignore hypo/hyper symptoms until it got severe enough, now I can just check within seconds to make sure whether that heartbeat is because I'm out and about or because of my blood sugar, whether my vision is because I'm tired or because of my blood sugar, etc etc. If you're extremely lazy and hate finger pricking like I do, it's an absolutely amazing tool.

Thrill said:

Thanks all for your replies, I do appreciate it. I'm willing to give this a shot and your suggestion @PIPPO_PIPPI sounds helpful, which bluetooth transmitter do you use and how do you 'apply it over the sensor' ?
Thanks all

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Hi Thrill.
You can find these info in the following Thread
"Freestyle Libre Transmitter for selfmade CGM" here
https://forum.fudiabetes.org/t/freestyle-libre-transmitter-for-selfmade-cgm/3594
BTW, I use the BlueReader.
It's very simple to apply over the sensor, the stuff is included with the transmitter.
Good luck!
Pippo

Thrill said:

which bluetooth transmitter do you

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I've been using the blucon nightrider transmitter from www.ambrosiasys.com for about seven months now in conjunction with the android app xDrip+.

One off cost of £96 for the transmitter, just hold it in place with a 7 by 8 cm plaster.

The transmitter sends a reading to the app every 5 mins, turming it into cgm

xDrip+ is a solid app. Many dexcom users use it in preference to the official dexcom app. Allows for calibration, gives hypo/hyper alerts, visual simulations on graph of how a bolus/carb intake might look, gives predicted low estimations long before the low might happen. Libre is good on its own but xDrip+ gives a whole lot more useful detail. Screenshot below to see what it looks like.

The apk is downloaded from here:
https://github.com/NightscoutFoundation/xDrip/releases

EllieM said:

Would it help with libre users who find that the libre reads LO when their blood sugar is 5 or 6? I am assuming the information to feed the xDrip just isn't there? I get night time readings which are just a solid mass of LO, despite the fact that blood testing shows my blood sugar to be normal... (Hence I'm not currently using the libre, but I do have one sensor left which I will eventually experiment with.)

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When I first got the blucon transmitter, I spent the first couple of weeks using both it and the reader, and bg testing quite a bit more just to get a feel for it. I was regularly getting situations where I was getting much closer readings with blucon and its inhouse app, linkblucon, and later with xdrip+ once it was modified to work with blucon.

Amongst those readings, there was certainly a couple where the reader said LO , but the blucon set up gave me a number which was reasonably close to the bg test, around 3.7 or so. Interestingly, that was the case even with the earlier linkblucon app, even though it didn't have a calibration feature.

The sensor will send the same number out and what matters is what the receiving app does with out - they all have different algorithms. The official reader seems to overexaggerate things whereas unofficial apps like linkblucon and xdrip+ seem to be less dramatic about.

I just use the reader these days to start a new sensor, and don't bother scanning with it anymore.

If you're thinking about experimenting with that remaining sensor, maybe you could think about trying it with glimp. I've not used it myself, but it has a calibration option, maybe that'll make a difference. Here's the instruction manual:
https://www.deebee.it/?p=1411#post-1411-_Toc485658007


There's a well known aspect of cgm called "biofouling", where foreign body defence mechanisms, biological detritus can clag up the sensor filament meaning that glucose around it just can't get to the sensor to be measured. A lot of work has been done by researchers and developers aimed at reducing biofouling. Of course, there will be instances where it's just a sketchy sensor from a bad batch, but I wonder sometimes whether people who are getting recurring bad results, incorrect LOs have a particular body chemistry which makes them more prone to biofouling. Had a hunt around for a paper on it but couldn't find anything.

Scott-C said:

There's a well known aspect of cgm called "biofouling", where foreign body defence mechanisms, biological detritus can clag up the sensor filament meaning that glucose around it just can't get to the sensor to be measured.

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Very interesting bit of info Scott. Having used 5 dexcom sensors so far my average life with 4 have been 22 days. Only one sensor hasn't made it this far, 9 days and it failed completely. This just happened to be the week I was struck down with the "Aussie flu ".
Biofouling???? Maybe or maybe not, but would be interesting if it was to happen again.

My last one definitely had some form of biofoulimg in its last eight hours. Readings crashed from high 7s to Lo in the space of an hour, even though my blood was reading 7s. When I removed it, the end of the filament had some gunk on that I had a real job to pick off. First time I’ve seen that.