CGM Only Works if It's Accurate

I had some real problems with my Medtronic Enlite sensor, which I think is just a lying liar.

I had a rather strong reaction to your posting about your Medtronic CGM not working. I don’t know all the rules about posting on this site yet, but I can tell you about my experience with Medtronic. It isn’t positive, for sure.
I had one of their sensors about 5 years ago. The adhesive irritated my skin horribly. I tried contacting them about this (I will say that I had their pump,too) and was given new sensors about 3 different times when I called. They acted every time I called like I was an irritating person that they just wanted to get rid of. Medtronic (used to be Minimed) used to be a great company. I felt they addressed problems with both their pumps and their sensors. However, Minimed was bought out by Medtronic and they changed. They used to have the majority share of the market and they felt they could put customer service on the back burner. Those instances with their sensor made me realize they aren’t the company for me anymore.
After all the squabble with the sensor and their refusal to really address the inaccuracy of their sensor and their horrid adhesive, I went with Dexcom.
I have to say that Dexcom’s customer service was 100% better than Medtronic’s could ever be.
Then, about 17 months ago, I was able to get a T-Slim pump. Tandem has an awesome customer service backup. But I digress. Back to the CGM’s. After being in a car with my sister about 3 years ago, I started the classical shaking with an insulin reaction. The lag time on the CGM was about 15 minutes at that time, so about 5 minutes (or more) after I pulled over, the CGM started beeping. It was at that time that I lost faith in sensors at all. I vowed that until the lag time became less, I wouldn’t even try one again. Just a week ago, I got a new CGM from Dexcom. It is MUCH more accurate than the previous sensors I had from both Dexcom and Medtronic.
My advice to you is that you need to give Dexcom a shot before totally saying goodbye to sensors. With me, after having the disease for 41+ years, there is some hypoglycemia unawareness. My husband has much less worry now that I have a CGM and can use it before I drive. He and I can handle together the low blood sugars at home and when in public, but it is much harder when in a vehicle by yourself.
I will never go back to Medtronic after my experience with them regarding their pump and CGM. As I said, they think they are mightier than any other company out there and I want people who can be humble when helping me. For me, that means Tandem will get my repeat business, as will Dexcom. Sensors aren’t perfect, but until they perfect a closed loop system, they are the only choice for me.

I’ve also had issues with elite sensor from Medtronic and not big fan of the pump either.

I love my DexCom G4…it’s usually within 10-15 points when I calibrate and often right on. Just sayin’

I got my Medtronic cgm in 2008 and had similar and worse accuracy and customer service issues than the person posting. I never until this year there were other CGMS out there. I finally got my DEXCOM in May and I love it.

Aargh, I have never been on the Minimed CGM, but I have issues with my Dexcom not being accurate! Just this morning I got a window of about 1/2 hour where they gave me the ??? sign (even though my CGM was right next to me) and then it gave me a reading of 339. I double checked with my meter and my sugars were 131. The frustrating thing is that when this happens (this much variance is unusual, though being 30-40 points off is not) I feel like the right diabetic thing is to assume I have a bad site and can’t trust the accuracy of the readings, and that I should change my site, and/or double check by testing more often using my meter and test strips. BUT my insurance only covers 4 CGM sensors a month which means I have a gap even if my sensors last the entire seven days, forget about changing a bad site after 3 days…

I am a CGM veteran. I even got AETNA to cover it before there were any treatment codes in 2007. I started out with the Minimed sensors and got no benefit whatsoever in terms of A1C. Then I had Dexcom seven plus which was much more comfortable. Seven plus took away the fear factor because I began to treat low BG before I was officially hypo. In early days of CGM, up to 8% of my numbers in a 30 day data set were lower than 70. That’s two hours a day people!

I didn’t learn how to prevent hypo in the first place until I got the Dexcom G4 in 2012. A1C went from 8.4 to 6.5 partially because of better accuracy. The big improvement came because I started photographing my G4 with my smart phone. I used the Line Camera App to add notes to the 24 hour photo I took each morning. I was finally able to see why I occasionally had a plus 25% increase in total daily insulin demand that lasted a few days, then mysteriously disappeared. Now I change my infusion set more often, and I use a methodical rotation plan for location. I religiously protect my insulin from overheating in a car. Insulin used to go beyond 30 days at room temp because I knocked it off the nightstand, and just resumed using it when I found it. Now I treat low BG at 100, and I am happy to let it ride when G4 shows BG flat at 150.

These are all incremental changes that sum up to no more big surprises. Now when insulin goes up from 38 units per day to 60, I know that piggy carbfest is the reason. The % of readings below 70 has been less than 2% for almost 2 years now.

I was diagnosed with Type 1 in 1991 at the age of 32. I have no complications. As an adult at onset, I understood the consequences of living with high BG, and I was overly aggressive in trying to achieve normal BG. CGM has been a complete game changer for me. Quality of life is so much better. It’s about the big picture not the accuracy in this very moment. Look at the data. Look at the data.



We are having major trouble with my sons pump and CMG. We live in Australia so the money of the CMG comes out of our pocket. It is a lot of money to spend for something that is not working.

In the night my son keeps getting an alarm that he is low or going low. When we check his sugars they are usually high. Does anyone know what could be causing this?

Also, he is now on his second pump for this warranty and it is giving him trouble. Had to have Lantis today. When he was at work it stopped delivering. This is a pump that is a month or two old! The last one was sending him low and then high and then low. Then one day it just died. We were working hard trying to figure out what was going on with his sugars.

Is there a better pump out there? When first getting the pump we were so happy. Now it is scary.

My first A1C in 2009 was 14.1 at the time of my T1 dx. I tried the MiniMed 522 insulin pump, but I had too many problems adjusting (mostly in my head…) so I was on Levamir long acting and Novolog for meal coverage. My A1Cs never got below 8.9 and the last one last September, 2014 was 9. I went back to my pump and got the Dexcom 4G CGM for tighter control. My A1C on February 23 was 7. Dexcom is amazingly accurate and I cannot say enough positive about that system. Soon I will be getting my new Animas pump that has integrated the Dexcom 4G receiver so I will be able to read my CGM on my pump.
By the way, the US Medicare system does not pay for CGM monitoring and that comes out of my pocket. $1100 for the system and $80 per sensor. The good part about the Dexcom system is that sensors can last up to 21 days even though the company advertises to change every 7 days. It is more accurate and cost effective.

I have no experience with either of these. But my company had a presentation with the CEO of Medtronic about a joint venture we’re doing. Our CEO went on and on about his credentials and qualifications.

However when he started talking, he sounded more like a marketing/sales guy. For example, he said that today most diabetics test like twice a day and write it down on a piece of paper and take it to their doctors office at their next appointment. I found this to be an interesting comment. I haven’t written a BS down in at least 20 years. Doctors offices download it from the pump and generate all kinds of graphs and charts. Maybe not the case for everyone, not sure.

But for a guy so plugged into diabetes care it didn’t sound right. A great story for selling CGMs I suppose. Then he said he wanted all of his CGMs to upload data to the cloud to be massaged and dosing to the pump could be controlled by that that will somehow save us money.

I have been a Medtronic Minimed insulin pump user since 1997 and a CGM user starting with the Real Time Sof-Sensor in 2007 and switching to the Enlite in January, 2014. I am a very satisfied Medtronic Diabetes customer! I know users of Dexcom who are also very happy, especially parents of young T1D children. My occasional calls for technical support or customer service have been very productive. I have received excellent support from the local Medtronic sales rep and the personal trainer who is also very responsive.

I am 76 years old and live alone. My CGM with Threshold Suspend, set at 65mg/dL, has prevented some episodes of severe hypoglycemia. I have not needed any 911 help for six years.

I am an advocate for Medicare coverage of CGM technology for more than five years. I am fortunate to have a Medicare Advantage plan that provides CGM coverage as an extra benefit. Unfortunately, many older people with T1D will lose their CGM coverage when they became eligible for Medicare.

Jerry Smith