CGM Freestyle Libre3 Questions

[happily single]

I recently began wearing a CGM (Freestyle Libre 3) and its interesting to see the changes in my blood sugar. I am pre-diabetic and have no other major health issues.

During the day I am within range over 95% of the time. I will occasionally get a Low Blood Sugar Alarm or an Out of Range alarm (even if the phone is in my hands). I have a message into my PCP, but while I'm waiting for a response

I'm having issues with two things:
1. Every single morning starting at about 3am and going until 6am I got woken up with the blaring, loud Low Blood Sugar Alarm. It gives me a reading in the 50's. I clear the alarm and then it says my levels are in the "normal range".

Any tips on how to stop this from happening? I did the research and follow all the guidelines: Making sure my levels are stable before bed, having a high protein snack before bed, etc, I don't drink alcohol, etc.

2. When I do get these warnings the low reading lasts literally a minute and rebounds to normal. I'm only in my first week of wearing the device so I'm not sure if the device is faulty or just the way my body works. Is it normal to go from 100 to 54 back to 95 all within 4 minutes? I'm giving basic numbers, but this is typically what I am experiencing.

 

[lanejudy]

DD and DH both use the Libre 3+.

1. is probably positional -- how you are lying and where the sensor is located. Next time you change the sensor try adjusting the location slightly. Probably not the best option, but we've been known to turn off the alarms at night. This seemed to be an issue for DD in particular when she first started using Libre3+ but hasn't been a problem recently.

2. As noted above, it's the sensor and your position in bed. Your glucose isn't really that low -- it's a false low. If it was a real low you would not bounce back that quickly. Any time you are concerned about a reading you should test manually. I think Libre3+ is compatible with the Freestyle Precision Neo test strips. Likely insurance won't cover them but I pick up a package at Walmart for about $15.

ETA: when it gets into the lower ranges, we've found the Libre sensor runs about 10 points lower than a finger prick. For example -- the alarm goes off with a reading of 64, but a finger prick shows it's 74. That's not with the positional lows but regular readings.

 

[happily single]

DD and DH both use the Libre 3+.

1. is probably positional -- how you are lying and where the sensor is located. Next time you change the sensor try adjusting the location slightly. Probably not the best option, but we've been known to turn off the alarms at night. This seemed to be an issue for DD in particular when she first started using Libre3+ but hasn't been a problem recently.

2. As noted above, it's the sensor and your position in bed. Your glucose isn't really that low -- it's a false low. If it was a real low you would not bounce back that quickly. Any time you are concerned about a reading you should test manually. I think Libre3+ is compatible with the Freestyle Precision Neo test strips. Likely insurance won't cover them but I pick up a package at Walmart for about $15.

ETA: when it gets into the lower ranges, we've found the Libre sensor runs about 10 points lower than a finger prick. For example -- the alarm goes off with a reading of 64, but a finger prick shows it's 74. That's not with the positional lows but regular readings.

How the heck do you turn the alarm off? I was able to turn off a few other alarms, but from everything i’ve read, we were unable to turn off the low glucose alarm.

I agree with it being about 10 points lower than a finger prick. I tested myself this morning and the fingerprint was 15 points higher than the monitor.

When I change out the monitor I’ll be careful of placement and see if it is a positional thing. I do tend to flip flop from right to left side all night

 

[lanejudy]

How the heck do you turn the alarm off?

Since I am not the wearer, I use the LibreLinkUp app and under Settings I can turn on/off all alarms as well as customize the range for alarms.

DH uses the reader, and I just checked but that doesn't seem to have a Setting for Urgent Low (default is 55). Maybe we have it on vibrate or something; he rarely goes that low but when he does it's almost always his position during sleep. The reader does have settings to turn on/off the low/high/signal loss alarms and customize the level for the low/high alarms.

DD uses the Libre3 app for iPhone. She isn't here at the moment for me to look at it it, but I think we played around with it for a bit and found a "Silent Mode" that she uses at night. I'm pretty sure she either has the low/high/signal loss alarms either turned off or set to vibrate because it really flusters her to have an auditory alarm go off.

 

[happily single]

Since I am not the wearer, I use the LibreLinkUp app and under Settings I can turn on/off all alarms as well as customize the range for alarms.

DH uses the reader, and I just checked but that doesn't seem to have a Setting for Urgent Low (default is 55). Maybe we have it on vibrate or something; he rarely goes that low but when he does it's almost always his position during sleep. The reader does have settings to turn on/off the low/high/signal loss alarms and customize the level for the low/high alarms.

DD uses the Libre3 app for iPhone. She isn't here at the moment for me to look at it it, but I think we played around with it for a bit and found a "Silent Mode" that she uses at night. I'm pretty sure she either has the low/high/signal loss alarms either turned off or set to vibrate because it really flusters her to have an auditory alarm go off.

I’m using an app on my iPhone. There does not appear to be any way to turn off the urgent, low glucose alarm. Nor does it appear to be anyway to change the number on it. It even says “This alarm is ON and cannot be modified”

 

[irlandaise]

I’m using an app on my iPhone. There does not appear to be any way to turn off the urgent, low glucose alarm. Nor does it appear to be anyway to change the number on it. It even says “This alarm is ON and cannot be modified”

I don't know whether this would be appropriate for you, but Abbott's Lingo CGM is sold for informational purposes only, so it doesn't have the alarms you've experienced with CGMs that are considered medical devices.

https://www.hellolingo.com/

 

[happily single]

I don't know whether this would be appropriate for you, but Abbott's Lingo CGM is sold for informational purposes only, so it doesn't have the alarms you've experienced with CGMs that are considered medical devices.

https://www.hellolingo.com/

Thanks. I’ll take a look into that one

 

[lanejudy]

DD says she uses “Silent Mode” overnight.

How do I turn on Silent Mode in the Libre app?​

Libre app* users can turn on Silent Mode‡ by following the steps below:
• Tap Alarms† on Navigation bar
• Tap the Silent Mode‡ toggle button
• Select desired duration and tap Save
• Tap Turn ON

Once Silent Mode‡ has been turned on, an “Alarms Silenced until xx:xx” banner will appear at the top of the app screen. This banner will not appear if there are other higher priority conditions to be shown, such as Alarms Unavailable.

 

[kdonnel]

I don’t have a CGM but researched them as a possible tool to add to my health care

It is my understanding that the readings will always differ from a finger stick. A CGM does not measure blood sugar but instead measures glucose in interstitial fluid. It lags blood glucose by 5-15 minutes.

It is also my understanding that you must use a finger stick to calibrate the CGM. Have you done that step?

 

[Pea-n-Me]

If you are not on any medication for diabetes then there’s a good chance your low alarms are positional. If you are on medication it’s probably not a good idea to shut off alarms even if you’re able to - you shouldn’t assume it’s positional. Many people on diabetes medication get low overnight, sometimes critically low, and you want to respond to that. If that’s the case and you change positions and it continues to alarm, you should get up and have some juice and check a fingerstick. There is a delay of probably 15-20 minutes before it starts to go up on the CGM so a fingerstick gives you more accurate information when you need it. Try not to lay directly on the CGM but even laying on that side can be an issue.

Just curious if you’ve had trouble getting these covered by insurance if you have been diagnosed as pre-diabetic? I agree they’re good to have as you can see in real time how foods and even exercise affect your sugars, which can be life changing. Unless on insulin many people have to pay quite a bit out of pocket every month for them even with insurance coverage. It would be nice if that were to change since so people can benefit from their use. Good thread.

 

[happily single]

I don’t have a CGM but researched them as a possible tool to add to my health care

It is my understanding that the readings will always differ from a finger stick. A CGM does not measure blood sugar but instead measures glucose in interstitial fluid. It lags blood glucose by 5-15 minutes.

It is also my understanding that you must use a finger stick to calibrate the CGM. Have you done that step?

Interesting information. Thanks.
I had no idea you should use a finger stick to calibrate the CMG. I will have to look at this

 

[happily single]

If you are not on any medication for diabetes then there’s a good chance your low alarms are positional. If you are on medication it’s probably not a good idea to shut off alarms even if you’re able to - you shouldn’t assume it’s positional. Many people on diabetes medication get low overnight, sometimes critically low, and you want to respond to that. If that’s the case and you change positions and it continues to alarm, you should get up and have some juice and check a fingerstick. There is a delay of probably 15-20 minutes before it starts to go up on the CGM so a fingerstick gives you more accurate information when you need it. Try not to lay directly on the CGM but even laying on that side can be an issue.

Just curious if you’ve had trouble getting these covered by insurance if you have been diagnosed as pre-diabetic? I agree they’re good to have as you can see in real time how foods and even exercise affect your sugars, which can be life changing. Unless on insulin many people have to pay quite a bit out of pocket every month for them even with insurance coverage. It would be nice if that were to change since so people can benefit from their use. Good thread.

I’m tending to agree with the few people who said it’s positional.
I didn’t have any trouble getting the CGM covered by insurance. I have a commerical plan through my state’s plan.

 

[lanejudy]

It is also my understanding that you must use a finger stick to calibrate the CGM. Have you done that step?

Freestyle Libre systems do not need to be calibrated.

 

[kdonnel]

Freestyle Libre systems do not need to be calibrated.

Good to know.

Does the documentation recommend finger sticks to get a baseline difference? Or does it just generically apply a rule to everyone that says an interstitial reading of x corresponds to a blood glucose of y?

In my reading it seemed like a CGM was great for big picture trends but not so great at actually letting you know your blood glucose in the moment.

A low or high warning by the CGM should be followed up by a finger stick to confirm, right?

 

[lanejudy]

A low or high warning by the CGM should be followed up by a finger stick to confirm, right?

Finger prick is recommended any time your symptoms don’t align with the reading. So a low alarm when you aren’t feeling hypo — yes, a finger prick; but that said, those who are more familiar with their situation may recognize that an urgent low alarm like OP questioned is most likely positional and will forgo a finger prick and just roll over. High alarms don’t necessarily auromatically need to be confirmed with a finger prick — DH routinely goes high after breakfast, and we know it’s largely due to what he eats. A high after a meal isn’t necessarily an urgent issue, but watch that it goes down again within 2 hours.