Constant Dexcom Errors

I switched to Medtronic, because it had a pump CGM system, but I don’t think the CGM is better, in fact, I’m considering changing to Dexcom and using the Tandem pump. Dexcom has new models out now. When I first got my Medtronic I wore my remaining Dexcom sensors at the same time. When I wore them both on my arms, they both were very close in accuracy. Medtronic CGM would become problematic for other reasons. And, I don’t think it’s available without the pump.

I hope you can find something that helps. It seems all systems have issues of some sort.

My father-in-law had Type 2 Diabetes and then “flipped” to Type 1 in his late fifties! It can and does happen. He was insulin dependent because he was no longer producing any insulin on his own. He had renal failure in his late 60’s early 70’s and was lucky enough to have a transplant after a number of years on dialysis. He was also able to receive a pancreas transplant. After a grooling recovery he lived a relatively normal life into his mid-eighties. Anywho, it is possible to go from 2 to 1.

That’s really interesting. Most people with type two who go on to require insulin don’t have autoantibodies, which is a hallmark of type one diabetes. Rather, their pancreases in essence “burn out” from tying to produce enough insulin to overcome the insulin resistance that is the primary feature of type two diabetes.

One can think of type two as a “metabolic” disease (wherein insulin is produced and put into circulation, but uptake in the tissues is not working for some reason) in contrast to type one, an autoimmune disease, where the pancreas is destroyed and no insulin or very little is produced.

But there are some area of overlap as well and as we know, some people with type one (formerly known as juvenile diabetes) can then go on to develop insulin resistance, (so, type two) and will benefit from medications like Metformin.

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Only a small part of the pancreas is destroyed, the Beta cells. The other 3 endocrine cells and the exocrine digestive enzyme functions are unharmed.


True enough. Although there are also other endocrine dysfunctions as I understand things, with alpha cell destruction or dysregulation and glucagon production abnormalities. Which I’m not certain occurs to the same extent in type two. But basically it’s an immune system run amok. As opposed to a metabolic switch that isn’t fully understood either (at least by me)

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@MBW I only insist on the pancreas not being destroyed in type 1 because it can be destroyed by various non-autoimmune diseases. This result in pancratogenic type 3c diabetes. These people depending on how extensive the damage may have to take digestive enzymes supplements with every meal along with insulin.

A totally destroyed pancreas is, in my opinion, the worst type of diabetes.


I am a type 1 for 45 years. I also have difficulty. For this reason I have not opted to have an insulin pump. I find the G6 works best on my arms not my abdomen as I have lost a day’s worth of data in the 10 days and on my abdomen it falls off. Yes Dexcom will replace but that can be inconvenient and then I need to keep track of when I started to use the transmitter.

Last night I had urgent lows at 1:30 am - 24 g CHO, 2:00 am - 20 g CHO, 4:35 am 20 g CHO and 5:50 am 16 g CHO. I did not verify and my blood sugar was 153 at breakfast while Dexcom read 130.

I use the Dexcom because my insurance will cover it and my endocrinologist relies on it to make adjustments, but I still do finger sticks at least 4 times a day. The best I can say with the G6 is to change it out a little more frequently. My endocrinologist has suggested every 7 days.

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If it is a sudden drop, perhaps a “compression low”. That happens when the body is heavily laying on the site of the sensor. It can throw the readings off for a bit.


Thank you for the suggestion. The problem, though, is that it doesn’t just happen at night. It happens equally in the middle of the afternoon, when there’s absolutely no possibility of compression. Does yours happen only at night?

We find the pump very convenient, not least because, as a Type 1, Mom frequently requires doses smaller than the integer increments a pen allows. She may need .65, or 1.3, and the pump allows that.

But we are concerned that the Omnipod-5 algorithm is being thrown off by Dexcom data failures. For this reason, every so often, we’ve been uninstalling/reinstalling the Omnipod app (including re-inputting all the settings), to clear out the bad data and start afresh.

Not that either company or our endocrinologist has given us any guidance on what to do for this. We’ve been pretty much on our own…

Sometimes, if I have my sensor on my thigh, and I cross my legs over he sensor, or have something heavy on my lap it can happen. It doesn’t have to be when you are sleeping and roll over onto the sensor

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I perceive all groups (Omnipod, Dexcom and endocrinologist) are looking for information. I refer to it as anecdotal cause and affect. The more these problems are raised the more there will be questions as to what is happening. All groups are dependent on what PWDs report. I think that is the only way that things will get addressed.

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No one flips from type 2 to type 1. It’s more likely he was misdiagnosed as type 2 but was really LADA. That happens a lot.
It’s also possible to be both type 1 and type2 at the same time.

However you can’t flip from one to another. They are different diseases that are mutually independent of each other with some similar indications.

Type 1 is usually an immune system failure where your beta cells in your are destroyed by your own immune system. Some cases don’t have antibodies but the beta cells still die off and maybe we just don’t know of all the different immune responses at play.

Type 2 is not a disease of your pancreas at all, it is a disease of other cells like muscle and fat cells that resist insulin.

Since type 2 will require ever increasing insulin to combat the resistance to insulin, the pancreas of a type 2 can often be over worked and begin to produce less and less insulin.
This is the same thing that sometimes happens to older people who’s pancreas is just old and putting out less insulin.
It is often called type 2, but really it isn’t. It’s just decreased insulin production.


I’ve experienced this as well but it only happens when I’m sleeping and am either laying on the Dexcom when I sleep or roll onto it. It seems any pressure on the Dexcom during sleep causes this problem.

But it’s always the issue that does it. The time I noticed it was one morning when I leaned over on my side and was reading the paper. All of a sudden it screamed at me with an urgent low reading!

It was 5.4 and then dropped to 1.9. Cause I had been leaning on it.

With the caveat that the alpha cells just lost their best friend and, thereby, lost their primary regulation (the beta cells dumping enormous amounts of insulin in their immediate vicinity).

This gives rise to the medical term, “impaired glucagon response”; it means that the alpha cells are unregulated and, in the unregulated state, produce glucagon continuously. That’s where the T1D basal requirement comes from; honeymoon period, LADA and so on.

Agreed, but the islets and their 4 cell types comprise a tiny bit of pancreatic mass. The majority is to produce and distribute digestive enzymes to the duodenum. A T1DM person saying the pancreas is destroyed is a simplified but misleading statement.

And both type 1 and 2 have alpha cell did function although different.

The poor individuals with pancreatogenic type 3c may have a totally destroyed pancreas with the complet loss of all 6 endocrine hormones and digestive enzymes. Some may have partial pancreatic function.

The O5 system “learns” our bodies across multiple pods. One of the important things that it learns is the basal requirement. I guess it is possible that the Insulet algorithms don’t work for your mother, one size does not fit all diabetics :slight_smile: I wish companies like Insulet had more person-to-person support but my experience is that it basically involves an interview to ensure that nothing has happened which must be reported to the FDA (in the US) then generic advice that very carefully does not cross the line to the endo’s turf.

The G6 has known failures, including the first day/last day stuff that you reported and the specific symptom, I call it a “drop out”, where the BG suddenly goes off, the G6 transmitter notices and then attempts to recover. It doesn’t always happen to me but it is quite characteristic, though the transmitter “rewrites” the data after the correction and that makes it less obvious.

Until the tech’ gets better we don’t have any choice but to live with it or not use it.

When we put the O5 on top of the G6 we’re putting bugs and approximations on top of other bugs and approximations. My approach is the one I’ve always used with computers; computers are idiots and I am moderately intelligent, so all I can do is help the idiot as best I can. I think we all learn, slowly, when the tech’ does work and then we work with it or, when necessary, round it.

The O5 system seems to be one of the best available (I don’t use it) and one of easiest to use (I use AndroidAPS, which I consider better, but it is not in the slightest way easy to use).

O5 does also allow remote monitoring which, while it is scary from the personal privacy point of view, can certainly be reassuring from the point of view of caregivers. You could discuss this with your mother’s endo; basically the endo pays for it (in the US) so either they do it or they don’t.

For people my age (63) or your mother’s I wish this stuff had happened 20 years ago, but it didn’t. I’ve been programming computers since 1972, about when I developed T1D at 12. I know a lot more about computers than T1D and, sadly, we’re still in what I call “alpha” stage of the development of effective computerized T1D treatment here. Most of it we did ourselves.

That’s why I said computers are idiots; I know way too many of them. We are not, but we must always remember that they are.

Interesting comment, John_Bowler, thank you!

Re the app learning the basal requirements over time, that’s exactly my point. As Omnipod gets more and more bad data from Dexcom, the algorithm seems to learn ever more badly, and then Dexcom keeps us all awake all night every night, as the Omnipod algorithm apparently dispenses increasingly inappropriate amounts of basal insulin, and my mother’s BG strays further and further from its target. Once we reset everything, though, it is so much better (for a month or two, anyway).


Never worn my sensor on my thigh - will keep it in mind as another possibility. Have been wearing mine on my upper arm for quite some time. Don’t know why I never thought of the thigh.

If I’m soaking in a hot tub, upper arm is a better choice than thigh for me.

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