False lows on freestyle libre2 at night.

Old’un

Active Member
Messages
32
Type of diabetes
Type 1
Treatment type
Insulin
I regularly have issues with my low glucose alarm going off at night when my blood sugar levels are not low. Normally I have the low alarm set at 4.5 but have been in the habit of reducing this to a lower level at night because it is too disruptive to my sleep. A typical example is that it went off saying 3.9 which I doubted. A finger prick test said 6.4. I have heard theories about laying on the sensors and pressure affecting them but I have this problem when laying on my back so it is not likely to be pressure related. Generally it seems to happen most shortly after first falling asleep but can happen at other times too. If I take notice of the low reading and have some carbohydrate then later in the night the high glucose alarm will go off and I end up having to have a corrective insulin injection. Is it just me or is this a common problem? Is Dexcom any better than libre for giving accurate results? Has anyone out there any experience with this or helpful suggestions please?
 

Nicola M

Moderator
Staff Member
Moderator
Messages
874
Type of diabetes
Type 1
Treatment type
Pump
The most common reason for false lows is from pressure readings, even a slight bit of pressure in my experience can produce those readings. I’m not sure where your sensor is on your body but whilst sleeping you don’t really know what you’re doing or how you are laying even if you do start on your back.

I would always check with a finger prick just to make sure it is reading correctly to avoid wrongly taking some carbohydrates and then going high later on.

In my personal experience I always found the libre to be inaccurate, I know that all CGM’s aren’t 100% accurate as they read behind blood levels but out of the 2 CGM’s I’ve had libre was far worse for accuracy. Like with Dexcom I wear the Guardian 4 which can be calibrated and in situations like this you can calibrate it so it’s more accurate.
 
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Smiler99

Well-Known Member
Messages
172
Type of diabetes
Type 1
Treatment type
Insulin
Dislikes
Needles
I had the same problem with libra it would go off and I would be just sitting in bed no pressure on it. Ring them up complain but keep a note of what it says and what your meter says. If it get bad ask to switch
 

AussieJen

Member
Messages
6
Type of diabetes
Type 3c
Treatment type
Insulin
I have found mine fairly accurate. I saw yesterday, while ordering more sensors, that Libre will shortly release (in Australia) a newer version with a claim of increased lower end accuracy.
 

Old’un

Active Member
Messages
32
Type of diabetes
Type 1
Treatment type
Insulin
I had the same problem with libra it would go off and I would be just sitting in bed no pressure on it. Ring them up complain but keep a note of what it says and what your meter says. If it get bad ask to switch
I have had several replacements sent to me when there have been a lot of major discrepancies. Abbott are very good at replacing sensors that malfunction but that does not help with disturbed sleep. Having had some very serious noct hypos in the past I am wary of reducing the low alar too much. I shouldn’t really complain I suppose as these sensors are so much better than boiling urine in a test tube which is all I had when I was first diagnosed.
 

Old’un

Active Member
Messages
32
Type of diabetes
Type 1
Treatment type
Insulin
The most common reason for false lows is from pressure readings, even a slight bit of pressure in my experience can produce those readings. I’m not sure where your sensor is on your body but whilst sleeping you don’t really know what you’re doing or how you are laying even if you do start on your back.

I would always check with a finger prick just to make sure it is reading correctly to avoid wrongly taking some carbohydrates and then going high later on.

In my personal experience I always found the libre to be inaccurate, I know that all CGM’s aren’t 100% accurate as they read behind blood levels but out of the 2 CGM’s I’ve had libre was far worse for accuracy. Like with Dexcom I wear the Guardian 4 which can be calibrated and in situations like this you can calibrate it so it’s more accurate.
I do find that most of the time the sensors work quite well and are very helpful. The night lows seem to be just after I have gone to sleep and I wake up in the same position as I went to sleep in. My wife confirms that I have not moved so I wonder if it is possibly a reduction in blood pressure when going to sleep which is causing the interstitial fluid to be replenished less.

I had enough trouble getting libre2 prescribed so I doubt my chances of getting anything else but I will raise this issue at my next review. They are a complete waste of time though and so far have never made any sensible suggestions or listened to my various concerns I have tried to discuss. They treat me like I am an imbecilic child and tell me that I should run my blood sugar levels higher as time in range of 90 - 95% is apparently too high, even if it is only slightly low 1 - 2% of the time.
 

Hopeful34

Well-Known Member
Messages
2,176
Type of diabetes
Type 1
Treatment type
Pump
time in range of 90 - 95% is apparently too high, even if it is only slightly low 1 - 2% of the time.
Well done on a fabulous TIR. It's such a shame that your team didn't congratulate you on this, instead of saying you needed to run your levels higher.
 

CarrieDC

Newbie
Messages
1
Type of diabetes
Type 1
Treatment type
Pump
I regularly have issues with my low glucose alarm going off at night when my blood sugar levels are not low. Normally I have the low alarm set at 4.5 but have been in the habit of reducing this to a lower level at night because it is too disruptive to my sleep. A typical example is that it went off saying 3.9 which I doubted. A finger prick test said 6.4. I have heard theories about laying on the sensors and pressure affecting them but I have this problem when laying on my back so it is not likely to be pressure related. Generally it seems to happen most shortly after first falling asleep but can happen at other times too. If I take notice of the low reading and have some carbohydrate then later in the night the high glucose alarm will go off and I end up having to have a corrective insulin injection. Is it just me or is this a common problem? Is Dexcom any better than libre for giving accurate results? Has anyone out there any experience with this or helpful suggestions please?
It's a constant nightmare for me. Every time I turn over in bed and I'm resting on my arm with the sensor, I get the alarm going off saying I'm low, which is a false reading, as when I then turn over on to my other side, it goes back up to the true reading. How the Omnipod is supposed to accurately learn my insulin needs with this going on every night I don't know. Not to mention night after night of constantly being woken up for no reason at all :-/ I've asked to change to the Dexcom sensor. It definitely can't be any worse.
 

AussieJen

Member
Messages
6
Type of diabetes
Type 3c
Treatment type
Insulin
Re effect of low blood pressure on interstitial fluid, I am very new to this insulin injecting world and this forum, which seems great in terms of sharing experiences and information.

I have not seen any info on BP and interstitial fluid. Could someone please kindly point me in a direction where this is explained?

I’m really pleased to have found this forum because it can seem pretty lonely at times trying to deal with all these issues, especially in light of some of the prejudices and misinformation around. I’m sorry Old’un has experienced this (and I’ve seen from others too) from our supposed expert support services. I think I have been very fortunate so far, only dealing with one educator who was not listening and was answering without understanding my questions as if I were a child or had dementia. Thankfully I’m able to see others instead, but it was a bit of a scarring experience.
 

mark cleaver

Member
Messages
7
Type of diabetes
Type 2
Treatment type
Tablets (oral)
Wow! That info is gold. I just couldn't figure out why I'd get a drop for best part of an hour in the early hours and then rises back to where it was before. That all makes sense now. Libre2 for 5wks now, paid for out of my own pocket!!. Learning a lot about effect of food. ( for interest, upon waking, morning readings generally around 6.2)