Should I get a CGM?

Hey guys, I have had type 1 diabetes for almost 3 yrs. I have been on the OmniPod insulin pump for about 2 yrs. My A1c was a 9.7 before the pump and within 3 months dropped down to a 6.7. Overall, my control has been better with the pump however I still have a lot of fluctuations. It seems like I struggle with going from high to low a lot. I think I would benefit from a CGM, but I'm not sure that I can afford one. What do they typically cost to purchase and for refills/supplies, etc.? I know my insurance company does not cover them right now, but that might be something I can work with. They would not cover my pump at first but they did after I appealed it and got my doctor involved. They "might" cover a CGM, but I'm wondering if it's going to be worth the hassle of fighting them. What do you think? I know I will still probably have a hefty co-pay, I did with the insulin pump. Anyone wearing a CGM, can you tell me a little about it? Is it uncomfortable or painful to insert? Does it help your numbers? Are there any CGMs available that are integrated in the pump? 

The main thing I am really concerned about is insertion. I am really small and have hardly any good insertion sites. I mostly use my arm and stomach for the insulin pump, but I even have absorption problems with that. There are many times when I get this bump under my skin where the insulin builds up and sometimes I bruise and bleed.

Hi Rachel.  I just got my first CGM a couple of weeks ago.  I am loving it so far!

Let me see if I can help with some of your questions.

Cost:  I have Kaiser HMO type insurance.  Dexcom gave me the Kaiser rate even though Kaiser would not cover any of the cost.  That put the cost for the transmitter/receiver set at $450 and a box of 4 sensors at $240.  Dexcom says to change sensors every 7 days, but other have gone longer.  I think 2 weeks on one sensor will be no problem, so based on that it would be $120 per month.  Then you'll also have to replace the transmitter every 6 months.  Not sure of the cost for that.  For me these costs don't represent a lot of money and I definitely feel that it will be worth the investment.

Sensor sites:  I have only tried two sites, but both worked with no problem.  The insertion hurts about the same as an insulin injection.  After insertion it is not painful.  I did not experience any bleeding.  I do not have a pump, but I understand that the pump cannula is larger than the sensor insertion piece.  I looked at mine when I took it out, and it was tiny!  It looked like a thin wire about 1/4" long and the width of a hair.  The Dexcom G4 is the newest CGM available, so it may be better in this regard than some of the older designs.  Some people get skin irritation from the adhesive but this has not been an issue at all for me.  The Dexcom sensor has its own integral adhesive, so there is no need to buy additional adhesive or tape over the transmitter.  I prep the insertion site with soap and water only, no alcohol.  When I removed the sensor I could see a tiny dot where the probe had been.  I'll be experimenting for a while with insertion sites to find one that is the most out-of-the-way, doesn't catch on clothing, doesn't interfere with my sleeping positions or other night-time activities, etc.

Integration:  The Medtronic pump and CGM are integrated in that they share a receiver so you can see all the info in one place.  I haven't used either, so I'll let others fill in the details.  Of course the holy grail will be closed loop control integration, AKA artificial pancreas.  I have heard rumors that Medtronic is developing this system, and that Dexcom is partnering with Animas for the same purpose.  The technology is already out there, now we just need clinic trials, FDA approval and products on the market.  I want serial #00001!

Performance:  I have definitely been able to get better numbers using the CGM.  I always had a pretty good idea of where my blood sugar was, but now I can see times and rates.  So I can tell by watching the chart how long it takes to digest certain foods, how long it takes different types of insulin to act, how long it will be until my blood glucose goes out of range unless I do something, etc.  Also there are the alerts for when I'm sleeping.  In my view the CGM is more important than the pump for improving control.


found a cgm pretty good at fine tuning a pump, I have the medtronic CGM and it's integrated with my pump (MM revel).  after I was done fine tuning I stopped wearing mine.  it's great feedback but the technology leaves a lot to be desired and imo, the sensors and accuracy are not so good.  if you are into technology, you can get the hang of the required sensor calibrations pretty fast, if you are not, it can be overwhelming.  for many, the readings are at least 15 minutes behind reality so if you are looking for early warning for hypos (esp around physical activity), they don't really work fast enough

the longest duration sensors go for a week, the shortest 3 days.  they are expensive.  many people trick the receiver and use the sensors for longer than they are rated for (I typically got 6-7 days out of my 3 day sensor)

the sensors have a fairly long "introducer" needle, but the sensors are flexible so once it's in and if you are not bleeding, they are ok comfort wise.  most go in at 45 degrees.  they are designed for "interstitial" so it's not like you are looking for fat tissue like a insulin injection site. still, the very top of my backside was a favorite site for my cgm sensor.

again imo, they really help if you have hypo unawareness, overnight low detection,  or are in need of a good pump basal tune up, but you can approximate a cgm with frequent testing.  good luck.