CGM? I don't think so

10/12/2014

The last weekend in October will be my first overnight camping trip with diabetes.

I’ve been working with my endocrinologist who wants me to get on a insulin pump and CGM (Continuous Glucose Monitoring) System. I tried out the Dexcom 4 Platinum and found out that I can’t base my dosing of insulin off the CGM. The Medtronic CGM (which is integrated into their pump) bases dosage off the CGM readings.

On Monday I put the sensor and CGM system to work in the afternoon. The CGM sensor fell out after 5 days. The CGM readings finally became accurate the latter part of Thursday and the sensor fell out on Friday at 5:45pm.

So I had a day and a half of good numbers from the CGM out of the 5 days it was in. I CAN’T base my insulin dosing off the Dexcom and it fell out before the 7 days due to my sweating.

I’m thinking I will have to do the same thing I did when I wanted to run a marathon. Multiple testings and playing with the snack amounts till I get it right. Good thing we aren’t going until 2017!!! I will probably need all that time to get this figured out.

Also the cost of the CGM and Pump is around $2400 with my insurance. That’s $2400 that I could use for supplies and other things so. My endocrinologist will probably get upset with me but I see NO benefit to backpacking the AT with a CGM and Insulin Pump.

Even though the Medtronic CGM is integrated into the insulin pump, it doesn't base insulin dosages off of the CGM readings. However, it will suggest how much insulin to take, based on numbers from blood glucose testing.

Until recently, I used a Medtronic pump and CGM. Over the years, I talked with their tech support reps quite a few times. Whenever a question came up about the CGM's accuracy (or inaccuracy), they always noted that the CGM can help identify trends and patterns in glucose management, but should never be used for treatment (or dosing) decisions. You might want to contact them, but I believe they would still tell you the same thing.

Still, my recommendation would be to use the pump, CGM and BG meter for your camping trip and/or any other activities. Yes, it's a lot to manage, when you'd really rather be enjoying your time away. But in my opinion, it's definitely worth the inconvenience for safety reasons.

The Medtronic bases doses off the CGM readings, but unfortunately those CGM readings may not be accurate enough to actually trust. I have used a Dexcom G4 since November 2012. It has a pretty steep learning curve, just like my omnipod pump, but once I had worn it for a while I was amazed at how accurate it is and I trust it implicitly. My sensors last 3-4 weeks each so it is cost effective. I used the G4 to help me during a 65 mile bike ride this summer from the Sagamore Bridge to Provincetown on Cape Cod. While there are certainly times I hate the beeping of the high or low alarms, it has alerted me to some serious nighttime hypos and for that I am grateful. CGM's are definitely not for everyone. If you have decent hypoawareness then they may not be worth the extra effort. But for those of us who don't feel hypos it can make a big difference in sleep quality among other things. http://dst.sagepub.com/content/early/2014/04/21/1932296814532203

I’ve used a CGM for five years now and wouldn’t willingly go without, especially if I were going on a backpacking trip. During the times when my CGM is doing its weekly 2-hour blackout, I feel like I’m flying blind!

While the Dex G4 warns about not basing treatment decisions on the CGM numbers, I often do just that. If my CGM is running pretty close to my fingerstick readings I just go ahead and use the number. If the treatment it suggests is a large insulin correction or a large food correction, then I’ll verify with a fingerstick.

As far as getting the sensor to adhere to your body during exercise, there are many measures people take to do that. Before I place a sensor, I thoroughly wash the area with soap and hot water with a wash rag. Then I place the sensor and paint over the top side of the adhesive with Skin-Tac, a liquid adhesive. Sometimes I put down a layer of Tega-derm on the skin, then place the sensor adhesive onto that.

There are many people here that pursue vigorous athletic activity and use CGMs. The two are not mutually exclusive.

Hey Terry - Why don't you have 2 receivers by now ? I have 2 receivers and never have to go through the 2 hour data blackout period. One is always a day behind the other one. The only time I am completely in the dark is during a brand new sensor session, but that is once every 3-4 weeks and I can live with that. My blood sugars have been really steady lately so it's not as critical to have the constant CGM data but 2 receivers definitely make that possible.

Thanks for the posts. Great advice. I'm just not certain this is for me. It took me a year to figure out how to run a marathon. I have till April 2017 to get the hiking and backpacking figured out. I hate the thought of the weight of the extra gear and I now know the inconvenience involved so I'm not certain it is worth it but, I'm open to change so we will see what decision evolves in the future. Thanks.

I am in the process of trying to get approved for the Dexcom unit.
From all the reading I have done and the comments of other fellow Diabetics, the general consensus seems to be that you can not solely base your dosing on the CGM.
In my case, I test really often anyhow, so there is no real inconvenience or major alteration to my routine. Instead, it gives me added data in the form of trends to get a tighter rein on things.
If you look at it that way as opposed to a way to eliminate your meter, I think a CGM is an incredible tool.

I've been CGM'ing for about 7 years now - first with the Dexcom 7 and then the Dexcom4 platinum. I still fingerstick 10-15x a day, and don't use the CGM reading for dosing. I do use the trend arrows when editing my dose. I find the trending info the most valuable. A fingerstick can't tell you that. We also have to remember that the CGM - no matter what brand, reads the insterstitial fluid, not blood. That's why we are advised against dosing from a CGM. My Dexcom 4 has helped me stay in range (60-130) pretty much 24/7. Yeah, I have rogue numbers, but then who doesn't. I am one of those people who uses Skin Tac. I pay out of pocket from my Dexcom, so I aim for 2+ weeks a sensor.

I used skin tac but I sweat 2 quarts an hour when working out. I DID measure my sweat rate for my training for marathons. So the sensors don't stick to well. I haven't tried the prescription strength deodorant before the skin tac and then the sensor trick yet. I may give it another go. Day to day normal use for me should be fine but I'm planning 6 MONTHS of hiking (burning 5000 calories per day) so for the Appalachian Trail I'm not convinced it will be the right method yet. Still working on it.....

I recently read about this product in an omnipod group. This is an antiperspirant that actors use to keep their make up on. One of the mothers swears by the stuff.
http://www.makeupmania.com/mehron-skin-prep-pro/?gdftrk=gdfV25867_a_7c2327_a_7c9826_a_7c3917&gclid=COfb0pL6q8ECFeRj7Aod1BUAHw

Thanks for the product updates. I think it will help if I go this way. I'd really like the Google contacts and watch set up but we will see.