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I first tried out the Dexcom back in June 2007 (here's that first blog post - forgive the inquisitive cat photos), when it was the Dexcom 3 system (with the crazy shower patches I had to put over the sensor and transmitter because it wasn't waterproof - that was fun, and was like saran wrapping myself every morning before work).  Even though I had reservations about wearing a second medical device and feeling a little gunshy about the potential data overload, I committed to the Dex technology almost right away because it made me feel safe

It wasn't a matter of not trying other CGMs - I did give the Minimed system that was available in 2007 a try, but it wasn't a good fit for me.  (Here's a detailed post about why I wanted a continuous glucose monitor and my experiences with trialing both systems, and also has a lovely .gif of some soap on a box.  So there's that.)  The Dexcom has been a huge safety net for me, especially during the before, during, and after of Bird-Building.

More often than not, this system works for me.  It's spot-the-eff-on and it often triggers me to double-check my meter results when they appear to be roaming around unsupervised.  I rely on the Dex.  It wakes me up when I'm low, it rattles my cage when I'm high, and Birdy thinks it's the best thing since Siah's tail.

Birdy calls the Freestyle strips "meh-cine bra."  Aka "medicine butterfly."

So when it's off, I'm thrown.  Last night, before I went to the gym, my meter gave me an 87 mg/dL and the Dexcom was in the same range.  When I came home from the gym, I was 215 mg/dL, but the Dex was lazily meandering in the lower range, yawning and eating potato chips and watching Are You Being Served.  Not even remotely tuned in to the fact that I was above 200 mg/dL.

"Nope."  I said, yanking the sensor out of my thigh.  

"Ouch," I said, as the new sensor slid into my other thigh.  (Usually they don't hurt, but this one burned a bit on reentry.)

I don't know what causes some Dex sensors to give up so easily.  And I'm not sure what makes me so stubborn.  This troubled little sensor gave me pause earlier in the week with a result much higher than my meter, but because I'm dia-frugal (read: aware of the cost of these sensors, and see also: aforementioned stubbornness), I restarted the sensor instead of pulling it out and putting in a new one.  Whatever the cause of this hiccup, I'm glad I caught this one as it went rogue, and I'm thankful I didn't make any treatment decisions based on the Dex's "recommendations."

New sensor is in.  So far it's in line with my meter.  And today I will test its legitimacy with plenty of coffee.  

[Dexcom disclosure]


Actually I'm off the Dexcom wagon right now for many reasons...sensor accuracy being the paramount one. Just can't justify the expense for only being right half the time. Maybe the next iteration of the system will be better.

I had the same issue yesterday with my Minimed CGM. It was buzzing and buzzing about my over-180 BG (with double up arrows), and then I did a fingerstick and it was 92.

It was on Day 5, so I'll give it that, but still.

I have found days 1-3 of a new sensor can be ridiculously wonky - skyrocketing highs that aren't really that high, and crashing lows that aren't truly that low. But days 4-14 or so are very close, and during that middle range are spot on with my finger stick meters many times. I calibrate mine with finger sticks at least 3-4 times a day regardless - makes me feel safer :)

I'm with you. It's a great tool. In one sense, I don't trust it and I won't dose myself based on it, but then get get mad when it's not spot on. Realizing it's limitations I'd still rather have it than not...especially when exercising!

When you say, "And today I will test its legitimacy with plenty of coffee." do you literally mean that coffee spikes your blood sugar? I'm talking straight coffee, no sweeteners, creamers, milks, or fancy fixings. I find that it does sometimes and I was curious if this happens to anyone else? Thanks.

the latest batch of sensors for me have all been off..very annoying!

It's catching! My Dex sensor was working great until I read your post this morning. Within an hour, I has a Sensor Error #1 (which I usually never get). Never could get it back, so I pulled it and inserted another. I was on Day 10 of that sensor,so it wasn't the worst. But sometimes you wonder....

Can someone explain the diabetes and coffee thing to me. I don't drink coffee so I don't know what the connection is, but I keep hearing about it.

I can totally relate to how reliant we become on these things. Saturday while at the gym, my Dexcom gave me a 117 straigh arrow down reading, followed by ???. I was so annoyed that I wasn't getting the valuable information when I needed it the most and had to test every 10-15 minutes in fear going low. But I really can't complain since that specific sensor's expiration date had already passed. But it was working fine before that! ;)

Interested in hearing about where on your thigh you put Dex. My 12 going on 13 year old uses the back of her arms exclusively, but is so very tired of all the comments about that "thing" on her arm. We told her we would pay her 100 to tell the next person that asks she just got out of Juvi and it is her homing device, but she wont do it! ;) Middle school is hard enough without having to deal with the d questions everyday. A sensor hidden on her thigh might be a great idea. She does sites there....hmm.. Top of the thigh?? Thanks for sharing!

I am not new to the sensor world (minimed for two years, dex for almost two) but I am new to using the dex on my leg.
So I went for a run on day two of the dex and the thing lost signal for the entirety of the run despite being clipped onto my waistband for the duration. Then when it re-established a connection it said I was 396. (meter reading:137)
Are leg sites just less accurate than somewhere more fleshy, like arms or belly?

I've been of the Dex for a couple months now. It was rarely accurate, and I am curious if that is because of the age (almost 2 years now) or if it had more to do with how much I exercise. I'm a 3 times a week gym go-er, twice a week yoga chick, and usually an hour of tennis in there. And after particularly hard workouts, I've noticed the dex is way off base. Has anyone else seen the same patterns?

I still wear the shower covers from the STS (ie 3 day) system! They protect the adhesive from water breakdown and give Each sensor the opportunity to function as long as its viable (rather than based on the durability of the adhesive). Sensors last at least 2 weeks , usually closer to 3.

I like your soap box. I personally think almost every person with type 1 diabetes should have this CGM.

Sometimes, coffee spikes BG levels because of the caffeine . It's different for each person, but many people living with type 1 (myself included) have to dose for the coffee we consume. ESPECIALLY if it's more than one cup. Which, for me, it normally is.lol.

Also, personally, if I indulge in an afternoon cup of coffee (sans the sugar and creamer) I don't need to dose. It's odd--has something to do with an insulin resistance thing in the AM compared to the PM.


Hope this helps!

This same thing happened to me in the middle of the night last night except my dexcom read 160 and my meter said 70! Then I got "sensor error #1" and had to recalibrate... Luckily it seems to be working again now, but this just reinforces why I always rely on my meter for actual treatment decisions.

I was very unhappy to discover that I was allergic to the sensors that Dexcom uses. Does anyone know of any solutions for this? I would like to be using a CGM.

I sense a title for a session for grown ups at FFL some day

Hi Kerri, this is one of the reasons I am wary of using CGM. In the UK we have to pay for the kit, even during key times like pregnancy. It is very difficult to get funding through the National Health System. I have tried, and failed. The cost of each sensor here is £60 which equates to around $95 per sensor. Far too much for it to fail with no explanation....

I also have a question about the dexcom sensor in the leg.. where in the leg are you "installing" it? (a picture would speak a thousand words) - I've tried in the back of my arm once and killed the sensor on install.. not sure if I hit muscle or what. I weary my Omnipod in the same location as I tried to install the Dexcom but have never tried again. I've not tried on the outside of my arm like the girl does on youtube... she seems to have more arm "area" than I do.

Any comments would be very welcome :)

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