Controversial thought - are we becoming too dependent on CGMs?

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helli

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Type 1
As part of the "old school" finger prickers (but not the old old old school wee testers), I have made a concerted effort to maintain my hypo-awareness: when I get too many, I run my levels higher for a couple of weeks to reset to baseline. I do this because my diabetes-self grew up with nothing apart from my body to tell me I need to prick my finger.
Now we have CGMs that can alert and tell us when our levels are heading downhill. This is amazing - I can catch a hypo before it happens. However, I still have the thought that hypos are to be avoided - if I need a dextrose to maintain my levels, I must have taken too much insulin so need to check my dosing. I live my life as if my CGM could fail.

I am sure many members feel exactly the same thing. So why this post?
I have read a few posts recently saying something like "my Libre failed so I didn't know I was having a hypo" or "I had a hypo because my Dexcom didn't warn me my levels were falling".

Hence the title of this post - are we becoming too dependent on CGMs?
They shouldn't fail but if it does, is the CGM the reason we hypo? I still think it is because I gave myself too much insulin. I know very well how complex insulin dosing is and how challenging it is to get it right. I but I still have the desire to do so.

Are we training ourselves to rely too much on our CGMs and worry less about insulin dosing?
Or, with the future of closed loop pumping getting closer, should we stop worrying about accurate carb counting and responses to exercise and let technology take the strain?

What do you think?
 
For my part, I pay attention, first and foremost, to how I’m feeling and will do a finger prick test to double check if I think my sensor shows a blood sugar value that does not match how I feel. Even an accurate sensor can become unstable towards the end of its life. I would caution against anyone having too much faith in the CGM, though I find it incredibly helpful in catching up/down trends while blood sugar is still within target (i.e., before my body’s alarm mechanism kicks in).
 
It doesn’t worry me for myself. I tend only to use the alarms when I’m exercising, or if I'm in a situation where I really don’t want the inconvenience of a hypo, so I’ll set the low alarm high enough to head one off. The rest of the time I’m so ingrained in the old way of a) avoiding hypos and b) spotting the symptoms early, that I don’t really rely full time on the tech.
What would worry me is having to go back to finger pricking full time, just because I remember the length of time it used to take to make adjustments, sometimes it could take a week before you got enough fingerprick data to look at it and eliminate all the anomalies and 'out of routine' days in order to spot a pattern.
It does worry me that newly diagnosed people are moved straight on to the tech, so haven’t ever known anything else. I’m still glad that if I’m on holiday, for example, and my sensor failed (and my spare didn’t work either), that I’d be confident to carry on for the rest of the time fingerpricking til I could get home and sort it out. That comes from having to rely on spot tests for years. I feel that even if people have been shown how to do it, without the experience to know it’s limitations, and 'fly blind' without the extra data of the trends in between fingerprick tests, they’d have a much more stressful time having to rely on the 'non tech' version.
 
I understand what you are saying and like @Robin I do have concerns for people who go straight onto Libre and do not have the grounding in using finger pricks to fall back on. I know that I sometimes need a break from Libre as it can be quite intense sometimes and what I really resent is how vulnerable I feel the first night without it, even though I am confident of my body detecting hypos and waking me up.
I think many of the people who say that their alarm failed and they didn't wake up for a hypo, likely just had a compression low so their body didn't wake tem up because they weren't actually hypo and it is important to understand that once your BG levels are stable and in range, your body may let your BG drop lower that during the day before it gives you warnings, because the body does actually like to drop a bit below 4 in none diabetic people during the depths of the night, so it might not wake you up until you hit 3, rather than your usual low 4s during the day. We have to remember that many early warning signs affect our conscious state rather than sub conscious... ie my first sign is often that my peripheral vision goes a bit blurry. In the dark, with my eyes shut and my brain not monitoring my sight, I can't expect to register that sign. Similarly, when I am lying down in bed, my legs are not going to get shaky because they are not holding me up. It is probably only when my heart starts pounding and releasing adrenalin, that it will trigger me to wake up, so that might not happen until I hit low 3s. I don't consider that an erosion of my hypo awareness, because during the day I sense those other signs in the low 4s.

What I am finding with Libre 2 particularly and having alarms set at 4.1 and 9.1, is that because it allows me to keep my levels more stable and in range (I am currently 98% TIR for the last 30 days), that my body is actually a bit more sensitive to the highs and lows because it experiences less variation in my BG. I can't really quantify this and it is more a feeling but I have been playing a bit of a game with myself recently of guess the BG before I do a scan and I am getting it right a lot more than I would expect to, so for me I think Libre 2 (and I was a huge fan of the original without the alarms and was reluctant to upgrade) may actually have improved my body's perception of my levels rather than dulled it, because it has enabled me to reduce the variability of my levels a bit more.

It will be interesting to see how I do when I take my next break from the Libre but I am happy to admit that I was wrong about Libre 2 and I am finding the alarms much more beneficial than I expected and my gut feeling is that is has actually improved my awareness both top and bottom or range..... but that may well be because I have reduced the number of hypos I am having. What I am now finding is that the occasional mild hypos I do have now, are much more unpleasant, so clearly I was experiencing some awareness erosion without the alarms.

The psychology of it all is quite interesting to contemplate as well as the physiological impact. It is very nuanced though. I wonder if I will feel more vulnerable when I next take a break because I rely on it so much, or less because my body feels better attuned.
 
I think some people set their Low Alert lower than I would - ie they set it at hypo point, eg 3.5. If your blood sugar is falling fast, by the time you’re 3.5 on the Libre, you could actually be in the low 2s. Over time, I think this blunts your hypo awareness. It also gives you less time to treat the hypo and get your blood sugar up. So, I personally think people can potentially use the Libre to ‘fly too close to the sun’. Some people do it unknowingly, but some do know what they’re doing. As their awareness blunts, they feel ok in the 3s and don’t worry about severe hypos because the alarm is there, but it’s not 100% foolproof, and it always makes me wince to see alarms set too low, or, conversely, High alerts set too low.

Not sure if I’ve answered your question there, but yes I think people rely on FlashGMs and CGMs to keep them safe and so think everything will be fine if they run too low. I think they’d be less likely to do that on fingerpricks, but the very fact the Libre, etc alerts can be ‘mis-set’ (IMO) almost permits unwise behaviour.

I love my Dexcom very, very much, but I still aim to be 5 or above to maintain my awareness. I also make sure I’m not tempted to mis-set my alarms.
 
Those are really interesting points @Inka. It does seem odd to me that some people set their alarm lower than 3.9 but I can understand why people would set it higher than 9 or 10 as a more normal carb diet will produce higher spikes and it would frustrate me if my alarm was going off after most meals when it didn't warrant any action. If I hit 9.1 I generally need more insulin, so I take action pretty well every time, but there are very odd occasions when I may feel I don't need to.

Setting my low alarm at 4.1 gives me the chance to turn things around with 1 or 2 JBs depending upon the arrow, before I hit the red (3.9) because I respond very quickly to hypo treatments and my top alarm is set at 9.1 because I am very slow to respond to insulin and if my levels get above 10 it takes a lot longer and a lot more insulin and frustration to bring them down again, so keeping below 10 as much as possible is important for me. This may well be as a result of my low carb diet, so may not work for everyone, but I feel like these levels allow my body to, more or less, mimic a normal person's range and I sleep a lot more soundly and more restfully in the 4s than when my levels are higher and I really like good, sound sleep, even if my Libre alarm goes off.

I think giving a lot of consideration to where you set your alarms and how that works for your body is really important and something that perhaps HCPs should look at more closely and discuss with patients.
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Cgm is life changing no doubt about that. Think what it can do though is encourage some to run their bg levels to low knowing that they'll be alerted by device, consequently consequence of that is losing hypo awareness symptoms, this is something I'd never want so don't typically stay above 5.
 
I explained badly probably @rebrascora For the High alarm, I meant people don’t set it high enough. Hope that makes sense now! It’s supposed to be a High alarm. I was told to set it at 13 or 13.5, and that people on injections could set it at 15 (higher risk of DKA on a pump) but some people set it at 9, 8 or even in the 7s.
 
Thanks for all of your thoughts. I think we are aligned ... but then we are all "old schoolers" to a certain degree.
I am concerned about people who are literally blaming their CGM for their hypos. I am worried the discipline of questioning why we hypoed is getting lost and the precision (as much as is possible) of dosing is become more slap dash.
 
Inka said:
I explained badly probably @rebrascora For the High alarm, I meant people don’t set it high enough. Hope that makes sense now! It’s supposed to be a High alarm. I was told to set it at 13 or 13.5, and that people on injections could set it at 15 (higher risk of DKA on a pump) but some people set it at 9, 8 or even in the 7s.
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No, I understood what you were saying, but was keen to explain why I set my high alarm lower. What works for me at 9.1 might cause other people to inject insulin when they don't need to. For me that 9.1 is usually the start of protein release and needs to be dealt with.
 
helli said:
I am worried the discipline of questioning why we hypoed is getting lost and the precision (as much as is possible) of dosing is become more slap dash.
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I'm sure that's a risk, and I'm sure DSNs will be learning how to advise patients who'll be assumed to have CGMs (and DAFNE and similar will be adjusted).

I completely agree it's not sensible to run low enough that you lose hypo awareness, but I hope that's unusual.
 
rebrascora said:
No, I understood what you were saying, but was keen to explain why I set my high alarm lower. What works for me at 9.1 might cause other people to inject insulin when they don't need to. For me that 9.1 is usually the start of protein release and needs to be dealt with.
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Ah, ok - thought it was me being incoherent :D Of course, individuals might vary in their needs and anyone eating a ‘different’ diet might need to adjust their settings. I get what you’re saying about protein. If I have just protein and veg, I get a later rise too. So, yes, more the mis-use of alarms than an actual number🙂
 
helli said:
Thanks for all of your thoughts. I think we are aligned ... but then we are all "old schoolers" to a certain degree.
I am concerned about people who are literally blaming their CGM for their hypos. I am worried the discipline of questioning why we hypoed is getting lost and the precision (as much as is possible) of dosing is become more slap dash.
Click to expand...
I have to confess my precision of dosing is very slap dash and that is as a result of Libre, but when I go back to finger pricking I do have to be more structured. The great benefit of Libre for me, (apart from not having to get my kit out and finger prick 10+ times a day), is taking the mental strain out of my diabetes management by making it responsive rather than preemptive. The important thing is that I know how to go back to the old school way of doing it and refresh myself every now and then with a Libre break, to keep my hand in and prove to myself that I can live without the tech if I need to. I still make a real point of listening to my body, even with the Libre, as much as anything because it fascinates me as to how clever our bodies are and that if we practice we can become more attuned to them than we are. I think Libre enables me to do that, rather than relying on Libre to take over that role, which is dangerous ground and I agree that some people are happy for it to do that.
 
I think the ‘allowing tech to take over and not using your brain’ can apply to other lower tech things too, eg bolus calculators. I’m always surprised by the number of people who follow it like it’s a command rather than a suggestion.
 
I find it surprising that people use bolus calculators at all, but again, I am guessing my diet and lifestyle means that they are of less use to me than others.
 
rebrascora said:
I find it surprising that people use bolus calculators at all, but again, I am guessing my diet and lifestyle means that they are of less use to me than others.
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I never used them until I got my pump but I still adjust the recommendation.
However, I am a mathematician at heart so I am comfortable doing mental arithmetic. I think this is a huge challenge for many people with Type 1 and bolus calculators help them through that.
 
I do think it's a danger, yes - but I've deliberately chosen not to even have any alarms turned on cos in very short order after getting Libre its lows were always false.
 
nonethewiser said:
Cgm is life changing no doubt about that. Think what it can do though is encourage some to run their bg levels to low knowing that they'll be alerted by device, consequently consequence of that is losing hypo awareness symptoms, this is something I'd never want so don't typically stay above 5.
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I've got my low alarm set to 5.5 (plus watching what the arrows are doing). It's worked really well at avoiding hypos.
 
I can find little advantage in finger-pricking now I have my Libre which I've had for 2 years now. Apart from cross-checking if I suspect my Libre is giving false readings I can find no advantage unless my Libre has failed.
 
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