Type I and CGM. Any tips?

I am finally on CGM!

I’ve been on the MiniMed CGMS with the Paradigm Pump for 2 days now and so far, it’s pretty cool. Already starting to learn the little quirks, but I’m curious if anyone has any tips or tricks to recommend. Anything you wish you would have known but didn’t discover until later? Tips for setting alarms or when to calibrate? I’m noticing that the CGM matches the BG monitor at lower values, but starts to diverge at the higher end or when glucose is changing rapidly. Here’s an example of some pretty decent agreement between the two.

I look forward to hearing your real-world advice!

(I was going to post this in the CGM forum, but I know A LOT of T1s here are also CGM users)

A couple things I learned the hard way: If you’re a stomach sleeper, do not put the sensor/transmitter on stomach. I wear mine in my lower back/upper tush area. Let the transmitter “steep” for a while before connecting the sensor. This tends to avoid a few hours of error messages. And once you have connected the sensor, wait before taping. You may need to disconnect and reconnect again before it starts reading. And lastly, when you’ve hit the over 1 year mark with it, and your sensor starts being very problematic as it reaches the end of its life, FIGHT minimed for a new one. Do not keep trying various unsuccessful suggestions they have and wasting a $30 a pop transmitter each time…

My tip to all CGM users - Don’t obsess over whether the numbers on the CGM and your meter ‘agree.’ A corollary to this is - Don’t pay as much attention to the CGM number as you do to the CGM line.

The two devices measure different things and serve different purposes. It’s like the difference between a GPS (the meter) and a compass (the CGM). One tells you where you are, the other tells you which direction you’re heading. One gives you a point in space, the other shows you a line of travel.

The meter tells you what your BG is at the moment when you need to make a decision about what to do - eat, bolus, eat and bolus, exercise, not exercise. Use it to tell you what’s happening now.

The CGM tells you which way you’re going - up, down, level, and how fast. Use it to see where you’ve been and where you’re heading.

Of course calibration is important, but the fact that the numbers don’t ‘agree’ doesn’t mean one of them is ‘wrong.’ Even two meter readings in a row won’t give you the exact same number. So a difference of even 50 points is not unusual and nothing to fret about.

Besides, if you spend your time making the numbers ‘agree’ you’ll not only use a ton of test strips, defeating part of the purpose of having the CGM in the first place, and you’ll go crazy.

Good luck!


Thanks for the tips! I know that it is possible to extend the 3d life of the sensor. Any tips on the best way to do this to ensure continued accuracy of the sensor? I’ve heard that 7d is about the max before you start losing accuracy…

Here’s my standard MM CGM spiel:

My schedule: insert new sensor Monday AM; start sensor before lunch Monday; restart sensor Thursday AM (after 1st SENSOR END notification); remove sensor when it expires Sunday; recharge transmitter overnight on Sunday.

Calibration: make sure you’ve got no active insulin or food in your system when you do the first calibration of a new sensor (or restarted sensor). It’s OK to have AI or food on board for other calibrations as long as you aren’t moving rapidly up or down. The key is that you want your blood sugar level the same 15 minutes after calibrate - that’s how long it takes.

Insertion: I insert in the love handle area and on my abdomen. I usually go in at about a 60 degree angle, but as I lose more fat in these areas (because bathing suit season is almost upon me!) I have to go in at a smaller angle. You’ll find the right angle after trial and error. I leave the needle in for a bout 5 minutes after insertion to stop the bleeding. If I see blood running into the cannula when I pull the needle out, I leave it in place for a while longer.

Reusing sensors: Always reuse the sensor at least once. I find the accuracy is best about day 2 - day 6 on a single sensor. I have kept one sensor in for 14 days before, but it left a mark I can’t get rid of and the itching about drove me insane, so for personal reasons, I only restart a sensor once.

I use Opsite Flexifix to keep the transmitter and sensor on. I find that if I put a little neosporin on the transmitter, it allows the transmitter to kind of “float” under the tape so it isn’t pressed hard against my skin. That’s what gives me so much irritation - the indentation made in my skin by the transmitter being pressed against it for 6 days.

And yeah - if you’re rising or dropping at a good rate, then the CGM will not keep up. But I find that for me, it is almost dead on for about 85% of the time. That’s totally worth it. I feel like I’m missing something major when I don’t wear it.