I wrote
last month about my diabetes diagnosis this year and my
difficult choice to wear a proprietary device (called a
CGM) on my arm 24/7
to continuously monitor my glucose levels. Like my friend and colleague,
Karen M. Sandler — who previously made a much higher-stakes choice to
receive a proprietary implanted defibrillator to keep her safe given her
genetic heart condition — I reluctantly chose to attach proprietary
hardware and software to my body.
Had a relative with a toddler that almost died due to his GCM overreporting his levels.
My mom had one and learned immediately not to trust it.
I’m shocked that both people I know personally had those devices turn out to be uselessly inaccurate…
Abbott claims they’re good for 14 days of use but my experience is that they’re worthless after 5 to 10 days. The first 5 days of use they’re about as accurate as the Dexcom units (typically +/- 10%). Beyond that they start to read increasingly low (-50% to -80%) with readings often failing entirely by day 10 or 11. It wouldn’t be a problem if you could replace them after 5 days, but if you do that insurance pitches a fit and refuses to cover more of them because “they’re good for 14 days”.
I’ve used Libre 1 for years, they work reliably. They will usually fail in the first hours of use, but otherwise work well for the 14 days.
Always keep a standard glucometer at hand, because these monitors can be affected by temperature and humidity.
Is this behaviour for a particular sensor, like the Libre 2, or do all of Abbott’s sensors do this?
It was my experience with the libre 2+ and the libre 3. I’ve never used the libre 1 so I couldn’t say if it applies to that one. That said the 2 and the 1 don’t really qualify as CGMs as you need to poll them for glucose readings and I believe they’re limited on polling frequency (something like once every 5 min) so they’re much closer to a traditional glucose monitor than they are a true CGM.