That is a pretty long title, I know but this is an important subject to the millions of people who are both diabetic and hearing impaired. This is only a portion of an article that I am currently writing comparing the CGMs that are on the market for the Abbott Laboratories FreeStyle Libre 2 glucose monitoring sensor. One of the reasons for this particular article is that I am extremely hard of hearing (legally deaf according to my audiologist) and a Type II diabetic.
Here are some of the basics that you will need to understand the entirety of this article. The Libre 2 is one of the glucose monitoring systems that Abbott Labs produces. They also make the Libre 1, the Libre 14 day, and the Libre 3. The Libre 3 is not currently available in the United States or Canada. The primary difference between the Libre 1 and the Libre 2 is that the Libre 2 has alarms for critical blood sugar levels (too high or too low.) It also has an alarm range that you can set yourself if you are so inclined. Interestingly, you can shut off all of the alarms except the critical low, that remains a fixed point of 55 mg/dL in the Libre 2 and cannot be altered. To be fair, 55 mg/dL IS pretty low.
The Libre 2 requires that you scan the sensor with either your phone or a scanner (that is usually one of the first things provided in your prescription, and Abbott does require that you get a prescription to obtain the sensors) in order to get a reading. While you need to scan, the reality is, your sensor is actually monitoring and sending information every minute in order to ensure that you are within the alarm parameters. With the Libre 1 you were able to use both an app on your phone and the scanner; with the Libre 2 you have to choose one or the other when you start a sensor.
Abbott Labs makes two primary versions of the Libre 2. One is for the U.S./Canadian/Australian market (abbreviated US from here on out) and the other is for the rest of the world. The one for the US is encrypted which limits its usefulness with the third-party Continuous Glucose Monitors (herein after referred to as CGM) out there. While the Libre 2 is an FDA approved medical device, NONE of the CGMs that attach to it are FDA approved or approved for use by Abbott Laboratories.
My criteria for selecting CGMs to use with the Libre 2 was actually simple. It had to specifically state that it worked with the Libre 2 US version, it had to have alarms, and it had to work with iPhone, and the Apple Watch. The last is critical for the hearing impaired. I do not use Android, but I have both an iPhone and an Apple Watch. The reason for the Apple Watch is when I take my hearing aids out, it is impossible for me to hear the audible alarm when my glucose level goes critical. The Apple Watch can be set to vibrate when there is an alarm which WILL wake me.
There were three (3) CGMs that I looked at:
· The Bubble Smart Reader
· The MiaoMiao
· The Ambrosia Systems BluCon NightRider
Unfortunately, NONE of these systems is great and NONE of them live up to their hype. For instance, while the Bubble Smart Reader states that it works with the iPhone, there is no app for it. You have to use an application that is essentially a test or sandbox through the TestFlight app. And, on their website, the ‘test’ is full. That means if you buy the Bubble Smart Reader, you either wait for them to get an approved app, or you find someone who has a ‘home brewed’ version of the TestFlight version that you can use (there are a lot of issues with this as well.) Run, don’t walk, away from the Bubble Smart Reader if you are an iPhone user.
The MiaoMiao, for the US Libre 2 iPhone user means you have one option as far as applications on the App Store goes; you must use something called the Tomato App. This application disconnects more than it connects. That is hyperbola, that is a simple fact. Trying to get any kind of customer service assistance is next to impossible. The unit is made in China and they operate on Chinese time (anywhere from 12 to 16 hours different than US time.) You can leave a message on their Chat on their webpage, but my experience is that they never get back to you.
The Ambrosia System NightRider was the best of the lot. While they have a dedicated application for their system (LinkBluCon,) it has a many, many problems. The primary issue is that the device disconnects from Bluetooth randomly meaning that you can go for very long stretches of time before you get a reading (their documentation states that it reads every five minutes, I would get periods where it wouldn’t read for almost an hour.) The worst part of this issue is that there seems to be some kind of conflict between the LinkBluCon app and the FreeStyle 2 app that causes the FreeStyle app to go into ‘Alarms Not Available’ mode and ‘Unable to Scan, please try in 10 minutes’ (yes, I know that this can happen without the NightRider attached, but I never had the problem before, and it went away once the NightRider was removed.) This can last for hours. If you are disconnected from the BluCon app and stuck in the ‘Unable to Scan’ mode at the same time (which happens frequently) during a critical period, you have to go back to finger sticks for simple monitoring.
I sent a series of suggestions and complaints to Ambrosia about these and other problems. They would normally respond in a fairly timely manner, but at some point this slowed to no response for several days. When I vented my frustration with them, they were willing to refund my money on the unit, which I consider quite honorable of them.
At this point in time, I am forced to say that there are no addon CGMs for the Libre 2 (and iPhone) that I would consider reliable. This is not to say that they will not improve in the future. A point to consider is, the Libre 3 is supposed to be true CGM sending data every minute, but it does not have Apple Watch capability. My contact with Abbott Labs on this indicated that it isn’t even on their radar.
I will let you all know when my article is finished and where you will be able to read it in its entirety. In the meantime, if you want to stay at least somewhat informed about the state of the units I’ve mentioned here, I recommend joining a couple of the Facebook groups that are specifically for the devices.