Continuous Glucose Monitors, Use and Experiences

[John_Hemming]

The problem with proper blood tests is that glucose metabolises in the blood so the test needs to happen quickly.

[CronosTempi]

I’ve installed my Lingo fom Abbott Saturday, September 28th, and the experience has been terrible so far. Completely off the wall readings, first day, surged to 200 and then just showed the ‘over’ symbol “>”, which means that it will not even display values above 200 (or below 55, as I found out)… I mean, WTF, how useful is that to someone with poor blood sugar control, when their sugar regularly goes over 200. I can see why this is not meant to be used by diabetics. Bloody useless.

But ok, I thought maybe give it 24/48 hours to adjust. It never did. The values literally can climb/fall 30 points within 2 minutes (it updates once a minute), all over the place with no rhyme or teason, I can be sitting surfing the net (not eating, drinking etc.), and within 5 minutes the stupid thing climbs to 125, plunges to 56, goes up to 110. It’s insane. At night, it regularly hangs around the lower limit of 55, and the graph breaks, showing it went below 55. It also shows long stretches below 55 during the day, not apparently connected to anything like food/drink/exercise/temp changes.

The one time I checked with my glucose monitor, the strip showed 129 after a meal, while Lingo was showing 159. And I have a lot of practice with the monitor, so I’m confident I did the test correctly.

It is so bad, I regularly show my wife the absurd readings, and we laugh at it: 55, soon 110, back to 69 and so on all while we’re just sitting in the car going somewhere.

I haven’t had the time so far, but over the weekend I intend to sit down and take a series of fingertip readings and record the Lingo readings at the same time.

Also, the app is absolutely useless. It shows a 6 hour graph, and you’re supposed to be able to scroll back for more, but the scroller doesn’t work. Also the date is stuck. First it showed Sept. 28 for two days, and then it’s been stuck at Sept. 30 ever since (today is Oct. 4). And mind you, I never logged out of the app since I installed it.

I don’t know what went wrong. I followed all the instructions carefully. Maybe somehow it installed wrong? Who knows.

But also a confession: I’m an idiot - I purchased the 12 week package for $249, instead of trying it out for a couple of weeks first. What can I say, I’m a moron, it never occurred to me that things could be this bad, I just assumed it would work.

Also, it’s been a week, but already by day 5, I felt itching at the attachment site, and now a slight soreness, I’m worried about an infection at the site. I cannot imagine lasting two weeks. And then take rapa?! Good Lord.

My plan is to try again with a new sensor, hoping the first one was defective, or maybe something went wrong when I attached it.

But so far it’s been 100% FAIL. Very dissappointed. I wonder if i shouldn’t throw the rest in the trash and try the Dexcom product, and if that fails, CGMs are just not for me. YMMV.

[adssx]

That’s very bad… I tried Abbott’s FreeStyle Libre 2 and the Dexcom G7: they’re also very bad in terms of UI/UX. I don’t have a glucose finger prick to compare, so I can’t tell about the accuracy.

[John_Hemming]

The web interfaces for both were ok. I prefer Dexcom. I have had blood draws tested with the CGM in place, but they have delay issues.

[Joseph_Lavelle]

Abbott FreeStyle 3 user interface was good. Lots of options for viewing data. Not great but good enough. I didn’t care for the low glucose alarm that I couldn’t turn off or silence by turning the volume down to zero.

[Beth]

After being woken up for no reason, I turn mine off at night, as well.

[John_Hemming]

It is not necessary 24/7, but it is useful to know what is happening. I last used a CGM in April 2023 (I think) and I am tracking things to ensure that I have maintained an improvement in glucose processing and to see what happens with Rapamycin.

Once I finish these sessions I may not do any more until I have a good reason.

I am not aware of any CGM records for high dose rapamycin.

[CronosTempi]

An hour and 15 minutes later:

Now it’s racing to the bottom, mere 34 points off.

Useless.

[RapMet]

Is the accu-chech proven to be accurate? pardon my ignorance, just now that i approach 60 started on this self-medication and longevity journey, and know nothing about these little devices. lol

[adssx]

That’s concerning…

Can this be the 15 min lag between CGM and Accu Check? Which CGM is it? And how accurate is the Accu Chek?

[CronosTempi]

Yeah, I’ve used this system for years. It’s very accurate, and this brand has a good reputation for accuracy. FWIW, a few years ago, at an appointment with the diabetes doc at UCLA, they did a quick fingertip blood check, as the nurse usually does before the actual doc sees you, and so I took the opportunity to check my Accu-Chek glucose monitor - I was prepared, and whipped it out and took a quick measurement on the same finger (since that was the one she sterilized), so the measurements were about a minute apart at most. The values were identical. I have been prediabetic for years now, so I regularly saw the diabetes specialist (that’s how I got prescribed metformin 500mg/day for a year before I quit it in disgust as it did nothing for me).

Now however I have a new plan. I’m going to UCLA for my annual physical and blood draw in less than three weeks. A few days before the appointment, I’ll install a brand new sensor from Lingo. When the time comes for my draw, I’ll have my phone out so I can see the CGM values in real time, and I’ll ask the nurse for permission for me to take a quick fingertip blood test with my Accu-Chek right before she draws blood, so that I’ll have three simultaneous blood sugar level test results. That should validate - or not - the various methods. I expect the Lingo to take a giant crap and be off by 30-40 points, and if both the Accu-Chek and the lab are very close, I can throw the CGM agaist the wall and then sweep it into the garbage. We’ll see.

[CronosTempi]

The CGM is Abbott’s OTC Lingo. There was no 15 minute lag. The readings were simultaneous - in fact, it’s slightly worse than that even, because while the readings were simultaneous, the photo was taken one minute later, as I had to grab my iPad to take the first photo. In actual fact, when the Accu-Check popped the result, 112, at that exact moment, the CGM was showing 74, and by the time I took the photo, it was a minute later and the CGM showed 75, while of course the Accu-Chek kept the same display, 112. If you squint, you can see the time displayed both on the iPhone app of the CGM, and the time on the ACCU-Chek.

So far, the CGM has been sh|t. Maybe the sensor is defective, maybe the installation went somehow wrong, or it just doesn’t work on my body.

[Barnabas]

The CGM might indeed be measuring poorly. The question about a time lag isn’t a question about when you checked with each device. It’s pointing out that the reading that the CGM does from the interstitial fluid is approximately fifteen minutes lagged relative to a measurement from your blood.

[CronosTempi]

I see. Well, the value rose slightly, but only by about 5 points or so for a few minutes, and then kept going down, so by the time I checked again an 75 minutes later, the CGM was showing in the 60’s where it stayed until I had my first meal of the day… all this time (I ckecked with the glucose monitor twice more), my glucose apparently was around 100 (98-104).

[RapMet]

@CronosTempi

Now however I have a new plan. I’m going to UCLA for my annual physical and blood draw in less than three weeks. A few days before the appointment, I’ll install a brand new sensor from Lingo

All good but why on this earth are you so intent in proving that some device is garbage and doesn’t work, when it fact you should be doing all you can to lower your glucose level my friend. first time in my life that my fasting glucose showed at 104 (always was around 90, a bit elevated within normal) and I’m not going to spent one single minute trying to see which device is garbage or not, and being such a smart guy that you are (obviously) why on hell you relied on 500mg metformin (advice from your dr.) and your glucose is still at 130? You know what I did when my glucose showed at 104?, I didn’t speak to nobody, didn’t ask no doctor other than some sporadic question from our great @DrFraser and some other great and knowledgeable people on these boards, and went on 750mg metformin (250mg AM, 500mg PM), went on 20 empagliflozin, AND also 50mg of miglitol with my main meal. Obviously, I start very low on all these but upped them to what is now after couple weeks, and that’s what I would think make more sense for you to do rather than spending your time getting two devices to fight with each other lol.

Can’t emphasize enough when people self-medicate, that the way to go is very low dose to start (i.e. started 125mg metformin one morning, no side effect, same at night, started 5mg ema no side effect, then I kept increasing after a week or so gradually when there were no sides). I must add I also get an adrenaline RUSH doing these things all on my own, as opposed to sticking to some script that someone gave you. Of course one needs to check blood markers etc… and it is a good idea to consult with a doc, but knowledgeable and smart people with the right attitude and the right approach can indeed become really great doctors to themselves LOL. I have my LDL-C a bit high at 104 and I intend to start Atorvastatin and ezetimibe in very low doses. Had started on 5mg of Rosuv but that did not sit that well with me so I’m going to switch to Atorv.

[CronosTempi]

Of course your questions and points make sense - but the reason I have not mentioned those other aspects, is because I didn’t want to derail this thread and make it all about me… the thread went toward CGMs and their utility, so that’s what I stuck to. That doesn’t mean it’s the totality of what I do wrt. my BG.

But since you ask, yes, of course I’m concerned. I had to push really hard for my PCP to send me to a diabetics specialist in the first place, since I was prediabetic. He wanted to wait until I became diabetic before doing anything about it. It took me awhile to move to medication, because I move rather conservatively (surprisingly!) in matters of health interventions. First of course I tried to maximise my diet/lifestyle measures. That done, I went with what was on offer from UCLA. After I exhausted conventional medicine - all the doc would prescribe is the metformin which transpired to be useless. Once I hit the wall there, I had to take matters into my own hands.

And so, I first must diagnose why I have such high BG, and this is not simple as I have none of the classic risk factors. I exercise - both aerobic and weights - extensively, but that only raises my BG (transiently). I increased protein and cut back on carbs, but that raised my FBG and my hsCRP (from 0.3 to 0.6). I’m at BMI between 21-22, and I plan on getting to 20, and in the next week getting a DEXA scan to see if I can cut back further on the fat/muscle ratio. My liver and kidney biomarkers are pretty outstanding. Seems like it’s basically too much sugar in the blood - but not due to too little insulin release, my HOMA-IR is bad, insulin pretty high. Looking at all this, it seem like the problem is simply too much glucose floating about in the serum.

My preliminary next step - get rid of that glucose. So, I already ordered empagliflozin from India which should arrive shortly (currently seemingly stuck in customs). I’ll start with 12.5mg and go from there. I also am switching from atorvastain 10mg/day to pitavastatin 4mg/day, as pitavastatin has zero impact on blood sugar, while atorvastatin can lead to diabetes.

Now you ask why am I so obsessed about these gizmos for measuring blood sugar - well, in order to monitor what my interventions are doing, I must have an accurate picture of the blood sugar levels. I was hoping it would be the CGM that would provide my constant ability to monitor. Now it looks like possibly I’ll be stuck with constant fingertip glucose monitoring stabbings - 5 a day, 10 a day? Too bad - I was hoping CGM=no stabbings. Apparently not. But either way, I need accuracy.

So you are 100% right. The priority is getting the blood glucose under control. And I intend to do so, but must have accurate ways to measure, which is why I seem obsessed with these various gizmos, for which I apologize insofar as inappropriately hogging the thread.

[RapMet]

@CronosTempi

I’ll start with 12.5mg and go from there. I also am switching from atorvastain 10mg/day to pitavastatin 4mg/day, as pitavastatin has zero impact on blood sugar, while atorvastatin can lead to diabetes.

Interesting to know that Atorvastain can lead or help get diabetes. Didn’t know that, I’m glad I “bothered” you to explain further . I’ll try that instead of Atorvastain.

[CronosTempi]

Regarding atorvastatin, rosuvastatin and pitavastatin vs new onset diabetes, please read for example this paper:

Impact of pitavastatin on new-onset diabetes mellitus compared to...

Quote:

Conclusions: In this retrospective, multicenter active-comparator, new-user, cohort study, pitavastatin reduced the risk of NODM compared with atorvastatin or rosuvastatin.

[John_Hemming]

What I like from a CGM is seeing the relative movements in glucose. I accept there may be an absolute variance as well. One check is seeing what happens to the stable (not exactly fasting, but not recently fed) glucose level which can shift a bit from sensor to sensor.

I think also as the sensor starts up the first 30 mins are unavailable, then it will have a reducing error for a day or so.

My main issue with CGMs has been protecting the implant, but with my current implant location that is not an issue.

I think the effect of my rapamycin dose on Glucose and RHR from 23rd September faded yesterday as my RHR dropped right down and the glucose levels were more reasonable although part of that may have been the change of sensor.

Say thats 12 days of 24 hours with an initial dose of say 75mg, almost 5 half lives of 60 which should take it down to a dose of 2mg.

The complexity of dosing is that you have initial effects (eg the inhibition of mTOR, followed by increased autophagy and sleep disruption), then further effects (the growth of new mitochondria by fission from unrecycled mitochondria), then further effects as the energy level of the cells increases and there are different splicing variants.

I think the glucose increase (which appears mainly to be increasing the base level rather than increasing the peaks although there is the double top on breakfast glucose) happens from an increase in hepatic insulin resistance which may be caused by mTOR inhibition.

[adssx]

@CronosTempi

The CGM is Abbott’s OTC Lingo. There was no 15 minute lag.

As Barnabas said, the 15 min lag is between CGM and finger measurements.

One endocrinologist told me that the only accurate CGM were Abbott’s Freestyle Libre 3 and the Dexcom G7. Lingo is the Freestyle Libre 2, it’s less accurate. See also: 6 Best Continuous Glucose Monitors for 2024

And this Lingo review: “With a MARD score of 9.2%—compared to 8.1% for the Dexcom G7 and 7.9% for the Libre 3—it’s noticeably less accurate. In fact, I spent most of my first day below 70 mg/dL, despite my dietary indiscretions. It did seem to become more accurate by the end of day two.” ( Product Review: Lingo by Abbott – Sarah Hormachea )

CGM can be less accurate on the first day so some people place them and only activate them the following day.

Finger prick monitors have their own accuracy issues. This article claims that Contour Next is the most accurate: https://www.medicinenet.com/which_glucose_meter_is_the_best/article.htm

I don’t know if the Contour Next is really more accurate but users report wide differences between Contour and the Accu Chek Guide as well: https://www.reddit.com/r/GestationalDiabetes/comments/196qeka/accucheck_guide_v_contour_next/

Here they also found that Contour Next was the most accurate by far (but they didn’t test Accu Chek Guide): Comparative Accuracy of 17 Point-of-Care Glucose Meters - PMC

But even for the Contour Next: “The CONTOUR®NEXT ONE meter specifically offers even greater outstanding accuracy at +/- 8.4%.” That’s compared to a venous lab draw sample.

The newest Contour Next Gen is even more accurate: Which is the Best Blood Glucose Meter for Me?|Compare Meters

Also: do you wash your hands well before measuring?

So, if you want to do a proper comparison: get a Freestyle Libre 3 (and pre place it or compare from day 2) and a Contour Next Gen (and wash your hands properly) and take 2 measures with the Contour Next Gen 15 minutes appart. Compare when your glucose is flat so not after waking up or after exercise or food. For instance before lunch or dinner. And if you want to compare to the gold standard: get a lab draw with the CGM on and get a fingerprick at the same time.