Hi there, I am not D but husband is and has had a few hypos in the past few years which have needed intervention from either me or the medical profession (had them all the time when little so things are a lot better in general)!!!
He travels a lot and we are thinking about forcing the issue of CGM with his specialist who is a bit backward with the new technologies!!
Can anyone tell me what the good and bad sides of using the CGM are and whether you think progress has already been made to sort out the teething problems?
I’ve only been on a CGM for a month, but I like using it. I use a Freestyle Navigator.
Inconveniences could possibly be:
-watching battery life of your devices involved
-possibly having “too much” information (this is what insurance claims is a problem) and overreacting to data
-it could encourage people to rely just on that information rather than manual fingerpricks (which you still have to do)
-sometimes if I wear it on my arm, I don’t feel comfortable in short sleeves (I’m a teacher)
-some devices have a short transmitter range (mine can pick me up anywhere in the house, but I’ve worn others that lost me if I left it on the table and went to another room)
-dealing with insurance coverage
Conveniences are:
-I’m prone to lows in the middle of the night and it wakes me so I can eat some glucose tabs and go back to sleep.
-I’m prone to post-meal highs and it lets me know whether I’m spiking or not.
-Mine is comfortable to wear in the arm or abdomen.
-peace of mind
-being able to glance at it while teaching or busy or whathaveyou and know whether or not I should stop and test or correct something
-knowing I can drive somewhere without having a problem
-knowing my husband can look over and see I’m alright while I’m asleep
-being able to manage my dosage timing better because I can see when the insulin takes effect
-being able to learn how to better manage certain problem foods
There is a lagtime of 10,15,20 minutes or so between the glucose level of your blood (fingers) and your interstitial tissue fluid (what the CGM reads). Your CGM tells you where you are and where you are trending by how fast you’re moving in one direction or the other, but you would not want to take that reading and dose your insulin from it - it could be off by as much as 20 minutes. Insulin doses are still figured via blood glucose levels. Especially since fast-acting insulin peaks about 45min after you take it. You could be off in your corrections by over an hour!
Secondly, you must calibrate the CGM devices to a blood glucose reading throughout the wear. My Navigator calibrates four times over 5 days of wear to a built-in blood glucose meter. The Dexcom calibrates twice daily with a One Touch Ultra over 7 days of wear. Not sure about the Minimed. I know it’s got a wear time of 3 days.
So you can rely on the monitor, yes. But you can’t expect the monitor to be something it’s not intended to be - an updated-to-the-minute replacement for a regulating pancreas. And no, I’m not testing as much as before. I’m down to 3 or 4 times a day from 10-12 times a day. Now, I test to take insulin for meals or correction, rather before and after every meal or before and after sleeping/exercising.
Melissa gave a lot of great information. I’ve been using the Minimed CGMS since late JUne and I really do like it. For me, the worst part is when I have a sensor that just doesn’t track well. I get frustrated, then I get mad. If I call Minimed about it I have to be really careful and try to control myself otherwise I just end up yelling at the person on the other end of the line.
When I have a sensor that’s tracking well, it’s fantastic and I do test a lot less. It helps to stop highs & lows before they get too high or too low.
Hello Emily: Melissa’s comments were very good. I have used the Medtronic CGM on and off for the last couple years, and have been less than wow’ed with it. Apparently, they just don’t work for 5-10% of the population, and I’m in that group. Even though calibrated properly, (in front of a Medtronic person several times in fact) I get discrepencies between the CGM and my meter of up to 60%. True there is a lag between the CGM reading and a meter reading, but my numbers were so far off that Medtronic finally admitted to the fact that they don’t work for some people. That’s one concern. Medtronic does warn people not to rely on the CGM for setting insulin dosges-they direct people to test with a meter before dosing. I’ve read alot of comments where people seem to rely on the CGM readings when setting doses. One shouldn’t do that, with the Medtronic unit anyways. So, I need to test regularly with my meter (even if I didn’t have such large discrepencies between my meter and the CGM).
When the CGM does track correctly, its a good way to show trends-whether my BG levels are raising or falling. That’s really what Medtronic says the devices are for.
The Medtroni units are somewhat pricey. The transmitter, which is warranted for only a year, goes for about $1,000.00, and the sensors, which last for three days (per “official” direction-my Medtronic trainer unofficially suggested using them for up to seven days) go for about $300.00 for 10 (sorry I don’t have the exact price-you can find it on the Medtronic website if that’s the unit you’re looking at).
You or your husband feel free to contact me with any questions.
I use the Medtronic CGM also, but at this point of using them since the end of September, I am really not happy with it at all…I like that it can help catch the highs and lows, but I have had the sensor alarm saying it’s low and I get up and check it with my meter and it’s about 112-140
but when it is saying it’s normal at about 119 I get up and feeling the shaking and crap and I check it on meter and it’s in the 60’s or lower…I do like sleeping with it, just incase it doesn’t drop…
I have been on the sensors since sometime around the end of sept beginning of October and 2 sensors left out of 2 boxes…So I have been through almost 20 sensors in about 2 months…I have had too many problems to list on here…Good luck
My navigator trainer told me that when you’re dropping quickly, because of the lag, you need to assume it’s 40 mg/dL off or more. If you’re dropping slowly, maybe 20 mg/dL. If in either instance you were falling or rising quickly, it’s reasonable to assume that your BGs were ahead of your CM readings. If you were stable, then I would assume it was sensor errors - which we all know happen. Apparently, the FDA approved it at this rate. (Something something-or-other plasma reading discrepancy something lab values blah.)
My CGMS has predictive arrows for a rate of change of 1 mg/dL per minute (45 degree arrows) and 2 mg/dL or more per minute (a straight up or down arrow). The trainer told me the rule of thumb was to note the point of the arrow, not the number, and do the math accordingly as described above, assuming I’m already where the arrow is pointing. 78 and straight down? I could be in the 40s. 90 and straight up? I might already be 130.
Considerations - your insurance may or may not pay for it.
As Melissa says, one of the ‘dangers’ of the CGM is overreacting to data. It takes awhile to learn not to ‘chase’ the CGM number with the meter number. They don’t have to match precisely, so get over it. The CGM is best for showing if you’re on the way UP or on the way DOWN - i.e. ‘for showing trends’. It also gives you a target RANGE to aim for - not a number to aim at. If you’re using a pump it’s also a great tool for testing your basal rates.
I think there are some good pros and cons here. I wore the Dexcom up until about spring when the warmer weather was starting.
My Pros
-Decrease of about 1 point in HbA1c (from low 6 to low 5) during my 15 months of wear
-Excellent correlation between finger sticks and CGM readings for the most part
-Able to treat lows and highs much more effectively
-Trend data with CGM vs. single data point with just finger sticks
My Cons
-Having something attached to me 24/7
-Being constantly reminded about diabetes
-Dealing with Dexcom on insurance reimbursement (too many follow-ups and reminders) when my health insurance actually covered device
Having said all this, I haven’t put the Dexcom back in yet. For me, I think it was the fact of having it attached to me always and all the follow-ups with Dexcom for them to submit paperwork.
Dawn and Melissa - You all might note that because of the algorithm that the Dexcom meter uses, it only has a lag time of about 5 minutes. Like drrps said, there is generally excellent correlation between what number it shows and what you see with a fingerstick. The difference between a 5 min lag and a 20 min lag was what made me choose the Dexcom system and I’ve been happy with it so far. I have a lot of failed sensors, but the company replaces the failed sensors for free, so I don’t mind.
I used a Dexcom for a week from my endo’s office and liked it alright, but I have never heard anything about an algorithm that solves the interstitial lag time issues in a CGM device. I am skeptical, to say the least. But I’ll look into it.
I liked the size of the sensor/transmitter pairing and the size of the handheld receiver. What I didn’t like was the lack of data available for review on the receiver (just the last day or 9 hours or whatever), the length of the transmitter signal (if I was more than 5-10 feet from it, it was gone), the length of the sensor probe under the skin, the gummy adhesive it left, or the fact that when I was anywhere near the treadmills at the gym it lost the signal. Maybe it was the one they let me use, but I had several issues with it that I ultimately wasn’t sold on. The sensor died on me on day 5, too. I know most people prefer the Dex 7 over the Minimed CGM (I know I certainly would), but I am a pretty avid fan of the Nav (of course, I waited on pins and needles for its release, so no shocker that I like it better). I’ve always liked Abbott’s diabetes care products.
For the record, the issues you describe sound pretty normal, so it probably wasn’t just your experience. The receiver is supposed to stay within 5 feet of the transmitter and does stop working if it gets much farther than that. I also notice some adhesive gets stuck on my skin, but I use extra adhesive, so I can’t say for sure whether that is the Dexcom thing or not. And it’s true that you can only see the last 9 hours of data on your receiver. The software to upload is free (or rather comes with the system starter kit) and it’s easy to upload, so I don’t mind that, personally since I’m almost always at my computer and can just upload whenever I want. If you don’t want to use your computer much along with it, I could see how that would be a downfall since you need the computer to analzye data over multiple days.
I don’t know much about the Navigator system and would love to hear more about it, but the 5 minute lag time was enough to sell me on the Dexcom system and (at least in my experience) it does seem to be extremely accurate. When it’s in calibration, the numbers I see on the receiver are almost exactly the same as what I see when I prick my finger. I always do a backup check since sometimes it goes out of calibration, but I personally like that better than always having data that is 20 minutes behind. My blood sugar can change a lot in 20 minutes!
