Continuous Glucose Monitor

[WhimsicalWays]

Hi everyone,

I am a 27 year old female, and have been Type 1 for 15 years. I check my blood approx. 10 times a day, and have pretty good control over my blood sugars. Because I am a little obsessive about checking my blood sugars (I volunteer with kids right now and like to know what I am while I'm supervising, and plan on working with kids full time soon. I also (obviously) check every time I drive, work out, eat a meal, etc.) I am considering getting a Continuous Glucose MOnitor (the one made by Medtronic in particular).

I would love any feedback from those of you who have used a CGM. I have heard calibration is key, but I am also curious about how often you test (To ensure accuracy) when using the CGM.

[I am no longer really considering an insulin pump (because I am a control freak, I am a bit uncomfortable with it. Also because my control is good, I don't see enough advantages).

Thanks very much for any personal experiences/tips!

 

[kegstore]

I have the Medtronic system to warn me about hypos (no awareness otherwise) and it's made a big difference to me.

The system requires a calibration 6 hours after the first, then it's every 12 hours until you remove the sensor - more on that later. For sensor accuracy the manual says not to calibrate more than 6 times in a 24 hour period - not sure why - so I've settled at 3-4 times evenly spread over a day, depending on what I'm doing. You can do as many additional tests as you require, just don't use them all for calibrating.

You probably already know how expensive the sensors are - £375 for a box of 10. If you listen to Medtronic, each one lasts just 3 days. Rubbish, I regularly get 6 days from each of mine with no loss in accuracy, and I've heard others get up to 14 days from the same sensor. Not sure I'd go THAT far, but at least I can certainly halve the cost to my PCT.

The sensors can be a bit fiddly to insert and set up so that they communicate correctly with the transmitter, and I still have to throw the odd one out occasionally, which I hate doing purely on cost grounds. In three separate conversations with the helpline I've heard three different methods of inserting them which is a bit useless, even with the insertion device provided. And they'll be no good to you if you're needle-phobic as the cannula is larger than a pen or syringe needle, at 23G!

The standalone system is marketed as Guardian Real Time I think? Not sure real time is an appropriate description - it's measuring glucose levels in interstitial fluid not blood, so can be up to 20 minutes behind the actual figure.

Overall though I'm very glad I have the system, it's gradually building up the confidence I lost through having some truly spectacular hypos in the past.

 

[WhimsicalWays]

Thanks so much, kegstore, for your response. I, too, have experienced some frightening hypos (often in the middle of the night, which made it that much trickier to catch) so the 'predictive' alarms for hypos is actually one of the main reasons I am interested in investing in one. That is a good point re: interstitial fluid vs blood and the 20 mins lag - something to think about for sure.

***Can I ask how often you still test with a glucometer? Like has it decreased significantly? I talked with another person recently who said they still test 8 times a day, and, frankly, I was kind of hoping RealTime Guardian would help me to decrease my testing a bit more than that...

I was a little shocked by the cost, and am looking into whether my medical insurance company will cover any of it (does not look promising... I am in Canada, so not sure how it works in the UK).

Anyway, thank you so much for taking the time to help me out!

All the very best...

 

[kegstore]

The nighttime hypos still get me - I'm such a heavy sleeper the alarm just doesn't wake me, but that's not a failing of the system, as it's SO loud and I generally need WW3 to break out to rouse me, such a teenager!

I probably test more with the sensors than I did without, and I've heard that's quite common. So probably 8 times a day? The system is not so reliable and accurate that you can totally rely on a sensor reading on which to base an insulin dose. So if you get a high or low alarm you need to test with a meter to confirm what the sensor's saying before doing anything. Sometimes it can be really accurate - within 0.1 mmol/l, but I've also known it to be 2-3 mmol/l out.

The cost is outrageous but there's a further point about extending the life of the sensors: apparently insulin contains an ingredient that makes site infection more a possibility when using a pump/infusion set arrangement. Obviously this just isn't present with a sensor so the risk is reduced, and I have to agree that I've never had any problems at all with a 6 day old sensor site, but sometimes an infusion site can go red and itchy within 2 days. The issue about extending the life of the sensors becomes more about accuracy than site infection, hence the 14 day stories.

Good luck with your insurance company, you may be in for a battle! And shout if you have any other queries too. :wink: