Upstairs, Downstairs with First-Gen Continuous Monitors
Emails and comments from fellow DexCom users are starting to pour in, and the split in testimonies
is quite striking: on the one hand, lots of folks are disappointed — even disgusted — at having invested so much hope and money into “a lot of expensive, inaccurate numbers.” On the other hand, I’ve got people telling me that the technology has saved their life — as in rescued them from hypoglycemic unawareness — and/or helped them finally hammer down their A1c after years of struggling.
This is not just about the DexCom product, either, since I’m getting notes from MiniMed Guardian RT users as well. They’re equally elated or exasperated, it seems. There appears to be no middle ground when it comes to trying these new CGM devices: you either love ‘em or you hate ‘em. Which means a few interesting trends are in the works:
* In terms of “viral marketing” (word-of-mouth endorsements), there are strong mixed messages shooting about, which will make for a lot of ambiguity in the marketplace, I think. Once the new, improved, next-generation devices are ready for sale, will people want to jump in? Or will they have heard too many horror stories from the “Downstairs” group?
* A grassroots resale market is quickly developing — meaning that people who’ve tried the products and want to opt out and recoup their money are looking to resell unused sensors and even full systems via the web. If you happen to be an “Upstairs” user, start checking D-message boards (and maybe soon eBay?) for discounted CGM supplies soon.
(I also understand there’s quite a {black} market for profitable resale of traditional glucose test strips. Read all about the Test Strip Thiefs here!)
In any case, you all know that I’ve been planted very squarely in the Upstairs camp on the CGM issue. But on this trip to Europe, I feel myself slowly descending. My experience here has been primarily a pain in the Arsch: the unit is so consistently off that I had to put in isolation overnight to avoid being woken by never-ending off-target alarms. In the morning, I’d try to recalibrate, but found that most days it took me well into lunch to get the device going again, only to find that it was still way off! Running around 70, when truly I was at 120 or above. Aaargh! Lots of time spent charging the unit and feeding it fingersticks, without a lot of value coming out the other end.
But I’m not giving up. My plan is to wear the thing for a solid three months in order to see if my A1c is truly and significantly improved. If yes, I remain Upstairs. If no, I dawdle about the staircase, trying to decide what to do next. Cross your fingers for me, Upstairs gang!
Explore posts in the same categories: CGM Adventures (Continuous Glucose Monitoring)












Hi Amy -
I’ve actually used both types and have a real love/hate relationship with them - love the DexCom and hated the other. For me it’s unusual for the DexCom to be off, while using the other one I was happy if it was within 40 points of a fingerstick. And rarely happy.
I do find the first day of the DexCom usually is its worst - sometimes I just give up and restart it the next day if it’s still off. But I wore my last one for 12 days and for the most part it was within 5 points of a fingerstick except on day 1.
I wonder if there’s something different with the sensors of the two brands that react differently based on your body chemistry?
Anyway, I’m curious about your trip - did you wear the DexCom on the plane? And did you just plug the recharger in an ordinary plug convertor or did you use some special adapter?
Posted by: Val | August 25th, 2006 at 12:33 pmCan some one recommend some soruces for diabetic sandals.?
Thanks
Posted by: doug | August 25th, 2006 at 1:26 pmHi Amy,
I’ve been using Minimed’s Paradigm 522/CGMS since June. The pump’s great, but it’s been a love/hate thing with CGMS so far (especially the 1st 12-24 hours of mostly inaccurate results). But like you I’m hanging in there because the trend values (ie, peaks and valleys) and low/high glucose threshold alarms have been invaluable. The CGMS has detected & prevented several potential hypoglycemic episodes. I set the low glucose alarm of my CGMS at 80 mg/dl. When the CGMS is callibrated and working correctly, my blood sugar will typically be between 65-70 mg/dl when the CGMS is 80 mg/dl. It’s a piece of cake recoving from a 65 mg/dl low versus 40-50 mg/dl!!! In addition to detecting lows, the CGMS has alerted me on 2 hyperglycemic episodes (my high glucose alarm is set at 140 mg/dl) that were caused by infusion set / site problems. So for now I’m sticking it out (with an occational break to clear my head!) for the benefits (vs. downside) it has provided me. The technology will only get better…pumps were a problem child when I 1st went on one 20+ years ago. Hang in there!
Posted by: type1steve | August 26th, 2006 at 6:57 amI’m waiting for the freestyle navigator. With 200 million diabetics and diabetes being the X(?) largest killer, I dont see why the FDA isnt fast tracking this technology.
Posted by: john | August 26th, 2006 at 8:47 amAmy,
I’m with you in the “upstairs” camp on my Dexcom. I just started a pump this week, and it’s great to have real-time numbers as I try to get my basal rate set accurately. (Though I wish I wouldn’t roll over on top of the sensor during the night - messes up the readings!)
My calibration experience/strategy is much like Val’s: expect the first day to be off. I get through the first day with a new sensor by doing some extra calibration and expecting the unit to be off somewhat. On the second day, I do a restart - that way you lose all the noisy values and bad calibration of the first day, and can start fresh. After that, it is usually smooth sailing for somewhere from four to ten days.
If your sensor is acting really flaky, try restarting rather than just chasing the bad calibration with more fingersticks. If it doesn’t work well after a restart (and the requisite few new calibration points), and it’s been in more than a day, then pull it and start a new one. If it’s been less than three days on that sensor, then call Dexcom and tell them to replace the sensor for free. We can put up with some flakiness, but there’s a limit!
Good luck, and keep us posted.
Posted by: Eric Jensen | August 26th, 2006 at 4:24 pmAmy -
Posted by: Val | August 28th, 2006 at 6:05 amYou may also try a different site. I had a lot of bad readings with a belly site, I eventually put it on the front of my leg, about a hand’s distance from the hip, and have much better success with that.
I’m firmly “upstairs” with the Guardian RT. I’ll admit I was actually surprised at its accuracy when I started using it! It certainly seems to be a YMMV issue, and strange that continuous monitors work so well for some and so poorly for others.
For me there is definitely an element of knowing what the numbers mean, rather than simply taking them at face value. For example, if I creep up to a reading of 11mmol/l (200mg/dl) I know that a fingerstick will read roughly 2-3mmol/l (36-54mg/dl) higher. That is consistent enough to rely on. Trends are also important. If I’m low but have got there slowly, the Guardian will be right on, but if I’ve got there quickly it will lag by around 1-2mmol/l.
As for calibration, when I first started I used to put in a calibration at times when the Guardian wasn’t agreeing with my fingersticks. It was almost a case of “damn you… look, you’re wrong!” I soon realised this actually did nothing to help accuracy, and I now only calibrate when the two are in close agreement and my blood sugar is not changing rapidly. As a result I have far fewer disagreements anyway!
In fact, I don’t get many ‘off’ numbers at all but interestingly the accuracy actually seems to be its best on days 7+ of the sensor. So much for the 72 hour lifespan!
Posted by: Caro | August 28th, 2006 at 2:41 pmGood news! I talked to Dexcom today. The software for users to download and manage their readings has been approved by the FDA, and is available for $79. They expect to start shipping next week.
Posted by: MikeG | August 29th, 2006 at 7:11 amEric Jensen (Aug 24) is RIGHT to recommend trying other places… although his success with upper leg is unusual.
For many people, if you put your Pump Infusers in your belly, you WON’T get good Dexcom Sensor performance there. I say that you should FORGET what the manual says (”as long as you’re at least 1 inch away from VISIBLE old scars, at least 3 inches from your current Infuser”). Rather, you should be at least 2 inches away from ANYWHERE you’ve put an Infusion Set during the last year.
The two places I recommend are: Love Handles– straight down from the armpit, and above the belt, NOT too high and close to the lowest rib. I know there’s not a lot of area there on shorter women, only room for about 4 “sites” on each side, but since I get 18-19 good days from every Sensor, I don’t have to go near an old location for about 5 months.
And Upper Butt Cheeks: Well above what you sit on, but be sure to be well below the “thin, bony” parts where there’s ligaments into your hip joint.
I started out on the belly, and after 2 weeks of frustration I was gonna send it back– then I tried my “love handles”, it’s been incredible.
BTW, I have my low/high alarms at 90 at 170… since there’s a delay when you’re falling or rising quickly, I don’t like the thought of waiting until Dex says 70: for me, bG would likely be 55 or less at that point. And going up, even with Dexc set at 170, my REAL bG is often approaching 200 when I get an “unexpected” buzzer. I prefer to keep the alarms tighter.
My results are so good that I’ve basically given up on finger-stick tests, and hardly ever do a “confirmation check” when the Dexcom makes a buzz. It’s ALWAYS been a correct indicator, except for once when I got it wet.
Posted by: Rick Stockton | September 1st, 2006 at 5:49 pmHi Rick,
I wish I could say my experience had been as amazingly positive as yours! But I’m still glad to be using it.
Regarding sites, I’ve settled on the very lower belly, inside my undies. Anyone familiar with female anatomy and fashion should know that hips are out for a bulging sensor, and I’ve got no love handles to speak of
Maybe the upper back B-cheek might be worth a try?
Posted by: AmyT | September 2nd, 2006 at 3:57 pmI used the hip area, aka: upper butt cheek ;-), for my last sensor insertion. Got the usual “out-of-wack” sensor results the 1st 24hrs, but since then I’ve gotten the best results of any sensor to date…and the sensor’s still in on day 9+! Like Caro, CGMS vs. blood glucose results are definitely correlating better the longer I keep the sensor in. Unfortunately I’m getting a little bleeding periodically from the site now, so I’m planning to put this sensor out of it’s misery and put a new one in before leaving on my business trip Tuesday.
Posted by: type1steve | September 3rd, 2006 at 2:41 pmAmy,
I am a *newbie* to CGMS, just started with the DexCom STS two weeks ago. I am off of the DexCom now, as I accidentally went swimming when my 8 year-old convinced me to jump into the frigid waters of the pool on the last day it was open, this Labor Day. I’m *hoping* to get another one soon.
I’ve started recording my experiences with it on my personal blog at http://www.mydiabetescgms.blogspot.com/
I figure, hey, if I’m doing all of this meticulous logging to see if CGMS is for me, why not write it down, someone may actually *read* it, share their experiences, and provide some tips, too.
I have 3 goals in mind, and then I will call my DexCom trial a success:
1. Lower my HBA1C by a full percentage point.
2. Reduce my hypos significantly, from the several per week to one or two per week.
3. Help me to adjust my pump basal rates more easily.
I do not expect the current state of the art in CGMS to replace finger sticks. I’m under no illusion that they have to be as accurate as fingerstick tests; I’m just considering this another tool in the bag, hoping that the trending information and alerts provided by the DexCom will help me reach the 3 goals I’ve stated above, without *too* many annoyances, like false alerts at 3 am. I’m interested in seeing where we all go with our A1C’s in 3 months.
- Gary, a member of the ‘upstairs’ gang http://www.mydiabetescgms.blogspot.com/
Posted by: Gary Krauch | September 5th, 2006 at 5:38 amI’ve had a Dexcom since July 2006. While I had fair results for 3 months or so, accuracy has deteriorated substantially in the product. I have had the unit replaced at least four times. The sensors fail often. Has anybody else seen this kind of deterioration over time ? Is dexcom having problems maintaining sensor quality ?
Posted by: Keith | January 19th, 2007 at 4:49 pmSo happy to have found this blog - particularly this page! I got my CGMS in September 2006 - it was GREAT until this January. Of my last ten sensors 4 were really off base (approximately 30% off from my BG meter - and not consistantly high or low) and the other 6 didn’t work. So far DexCom has been willing to credit me for the sensors that didn’t work - but that doesn’t help when I can’t get them to work!!! Keith - what did you say to get them to replace your unit?
Posted by: Kristine O'Brien | February 15th, 2007 at 12:21 pmI’m convinced it’s improper use and expectations that lead many to the downstairs camp.
CGMs should be used to PLAN for situations, not react to them. The values will always be 10-12 minutes old because it’s reading from fluid in the skin and not directly from the blood. It’s also important to insert and calibrate during a period of relative stability. THis is really important, because much can happen in a short period of time. Your first reading (12 minutes old) could be way off from the current situation - and thus throw you off. It’s also hard for the device to lock onto an accurate number if your BG’s are all over the place during the calibration period.
I also recommend wearing the device for a week or 2 of moderate activity to observe how food and exercise affect your BG. Once you become accustomed to it, you’ll be amazed at how well you can anticipate (not react to) almost any situation. My BG had been fantastic for 2 months now. Good luck y’all!
Posted by: James | September 4th, 2007 at 6:47 amFlipping screens, moving screen… blah. When do they come up with a screen-only with a virtual keyboard. Just the screen…www.birmarket.com
Posted by: Seren Griwi | May 15th, 2008 at 6:14 pm