Libre sensor positioning

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agentmole

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Type 2
I have been using Libre sensors for some years now and now use the Libre 2, I’ve always positioned them on the back of the upper arm as recommended by Abbot. Occasionally if I sleep on the arm to which the sensor is fitted I get a hypo alarm during the night, this led me to always sleep on the opposite side! So two weeks on left side then two weeks on right, switching the sensor between arms. I have seen some utube videos suggesting alternative positions like the chest, abdomen or thigh, any of you guys have experience with alternative sensor positioning?
 
During Covid and lockdowns, I had a series of sensors on my chest. These gave a similar performance to those on my upper arms. I suggest the 2 main issues are:

If you get a failure in a different position to the approved or recommended position then Abbott would be within their right to deny you a replacement.

If you are a driver then Libre 2 (or any CGM) is only legally allowed by the DVLA if its in the manufacturer's approved position. In practice because of lockdown I was driving very infrequently and was happy to do a finger- prick each time I took the car somewhere. I'd already had a year of MDI without a sensor - so the remit to test before driving was not a big deal. But it is perhaps worth reminding you that alternative sensor positions need the DVLA remit to be considered.

If you don't like the upper arm position try alternatives for yourself. Diabetes is all about "trial and learning".
 
Used libre 2 on chest & stomach before noticed no difference in accuracy, must admit never took into consideration about dvla regs so something to think about there.
 
I am always intrigued by the concern about following the DVLA regulations to the letter.
I am not a lawyer but, if you can prove the placement does not affect the accuracy for you, does it matter?
Likewise, if using an unofficial app like xDrip which, due to calibration, provide far more accurate readings than LibreLink, why would the police be concerned?
Do the police/lawyers understand these tiny details?

I confess I have a slight tendency towards rebellion for a good cause, especially when the law appears so illogical.
I have never needed to test it (maybe I would think differently if I did) but who else has? Has anyone had to show their Libre readings to a police officer? Could they make any sense out of it?
I do not consider myself reckless. I always check before driving and every 2 hours (approximately), I keep a close eye on my speed and keep an eye out for pedestrians when driving. But I do not use an inaccurate CGM.
 
helli said:
I am not a lawyer but, if you can prove the placement does not affect the accuracy for you, does it matter?
Click to expand...
My concern would be, if you did actually have a hypo whilst driving and crashed. Let’s say it’s a mild hypo of 3.8 that didn’t affect your driving, you were on the motorway, ate some carbs and were going to pull off at the next exit. Or let’s say it was a sensor that went dodgy, reading too high and you had the mild hypo of 3.8 same as above. That can happen with the real app given the margins around bgs so I’m sure it could happen with an alternate site or app. Then something happened to cause a crash that wasn’t entirely your fault. Your body then reacted to the shock by dropping bg lower before the ambulance came.
Would someone then use the fact you weren’t using the libre app to mean you hadn’t tested before driving and try to say you were driving unsafely etc and get you convicted of something? Or would you be absolutely certain your alternative site or app is accepted.

I know all the above is in reality unlikely, but honestly it takes 5 seconds to do a fingerprick for peace of mind that you’ve followed the law when driving if you use an alternative site or app. How would you feel if you advised someone it’s fine to use something unofficial and something happened because of it.

I may walk on the cautious side regarding driving as I’ve also had experience of a crash that left a close family member unable to walk for over a year, in hospital for the best part of a year, still recovering from the brain injury 4 years later.
And most relevant was the complicated court case that took years to go through and was a massive stress for the whole family. The driver tried to pin the blame on the family even though none of us were actually driving (it was a taxi), and there was several incidences of harassment from the driver causing more police involvement. A car crash can affect multiple lives for years, I wasn’t even in that car and it still affects my life, and where I live and work, providing care etc.

Why take any risks for the sake of a test.
 
Yes, I also see a worst case scenario as possible. If there were an accident that resulted in serious personal injury to someone else I strongly believe that the police would realise that my licence can be tracked back to being "special" arising from my insulin dependency and they would be obliged to make sure that I was in full compliance with the rules, etc. I don't imagine that if stopped because of some road safety infringement this might occur. But the constant erosion of common sense, the steady removal of a police officer's authority to exercise judgement and the bureaucratic dogma that replaces judgement with written protocols and form filling could easily trigger detailed compliance checks.
 
Amity Island said:
@everydayupsanddowns
I know this is a long shot, but could diabetes uk contact abbott and see if they could extend their testing to include others sites of use?
Click to expand...

Abbott have looked into alternative sites and published data and conducted research into how sensors behave in other locations. I’ll see if I can find the paper.

My recollection is that the error grid was found to be wider - which is why locations other than back of arm are still not recommended.
 
everydayupsanddowns said:
Abbott have looked into alternative sites and published data and conducted research into how sensors behave in other locations. I’ll see if I can find the paper.

My recollection is that the error grid was found to be wider - which is why locations other than back of arm are still not recommended.
Click to expand...
I look forward to reading the paper, Thanks Mike.

So, conclusion of the trials found under the arm to be the only suitable place to give accurate results? if it is, that's an interesting fact in itself. I always believed it was decided to put it under arm to avoid being knocked off.
 
Dexcom One is available on prescription. Unlike the Libre, it can be fitted to the arm, or abdomen without any change in accuracy. If you have a smart-form phone the App will work within 6metres of the sensor to give your BG, and if you have a compatible watch, the App should appear on your watch. My level currently is 7.7 (I leave it open, so I just glanced at my watch). If you have neither, then a reader is availlable.

The transmitter from the sensor (which is fitted to the sensor) lasts three months, the sensors last for 10 days, so a months supply on prescripiion is three sensors and one transmitter.
 
Amity Island said:
I look forward to reading the paper, Thanks Mike.

So, conclusion of the trials found under the arm to be the only suitable place to give accurate results? if it is, that's an interesting fact in itself. I always believed it was decided to put it under arm to avoid being knocked off.
Click to expand...

I can’t find the link in the FB group that I thought had it listed.

This is earlier than Bruce’s paper (2018 vs 2022) so may have been it?

pubmed.ncbi.nlm.nih.gov

Accuracy and precision of flash glucose monitoring sensors inserted into the abdomen and upper thigh compared with the upper arm - PubMed

Nowadays, most Belgian patients with type 1 diabetes use flash glucose monitoring (FreeStyle Libre [FSL]; Abbott Diabetes Care, Alameda, California) to check their glucose values, but some patients find the sensor on the upper arm too visible. The aim of the present study was to compare the...
pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov

tldr; Back of arm marginally better, thigh not bad at all, abdomen poor.
 
everydayupsanddowns said:
I can’t find the link in the FB group that I thought had it listed.

This is earlier than Bruce’s paper (2018 vs 2022) so may have been it?

pubmed.ncbi.nlm.nih.gov

Accuracy and precision of flash glucose monitoring sensors inserted into the abdomen and upper thigh compared with the upper arm - PubMed

Nowadays, most Belgian patients with type 1 diabetes use flash glucose monitoring (FreeStyle Libre [FSL]; Abbott Diabetes Care, Alameda, California) to check their glucose values, but some patients find the sensor on the upper arm too visible. The aim of the present study was to compare the...
pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov

tldr; Back of arm marginally better, thigh not bad at all, abdomen poor.
Click to expand...
study "some patients find the sensor on the upper arm too visible"

This is why I like it! Short of wearing a diabetes bracelet, it would give people an indication of your condition should anything happen.
 
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