It's been just over two weeks, and I'm hooked. I can't imagine going back to simply sticking my finger several times a day, or every few hours at most...
As the DexCom rep put it, it's like we used to be driving along in a car with the windshield blocked out, and only every now and then would someone pull the cover off so we could have a quick glimpse of where we were on the Diabetes Road (not even a look at the road ahead, just a quick peak at where we were that very moment). Then suddenly we got this new navigation system, the Continuous Glucose Monitor, which lifted the cover off the windshield permanently, so we could actually see -- all the time -- where we are, where we're going, and even where we've been. Wow!
That said, I've had some serious accuracy issues with the (first-generation) DexCom. Last weekend, I had an afternoon where the DexCom had me running 180-190, while the OneTouch (traditional meter necessary for calibrating the DexCom) had me in the 140-150 range. That's a big difference to me -- the difference between correcting and "riding out the high," actually. That evening, DexCom had me at 156, while the OneTouch clocked in at 228. Wtf? Whaddoo I do now? Double-check with my old standard FreeStyle Flash meter, of course. 216. OK, correction city!
The following morning, DexCom made me smile with a reading of 128. But I lost my grin when I checked the OneTouch and got 188. The FreeStyle agreed, so I dialed up an aggressive breakfast dose.
By this point, understandably, my faith in the whole thing was going out the window. So I called DexCom tech support. They're very responsive and helpful, I must say. But that doesn't make the device more accurate. The DexCom support folks told me that up to a 30% delta between the CGM and the traditional meter was documented at this point. Aaargh!
I know this accuracy gap is quite upsetting to some people. But I firmly believe that one cannot and should not give up too soon in this early, pioneering phase of CGM use. Hear me out...
As all of us in the current Field Study are realizing: right now it's not so much about the individual number(s) as it is about spotting the trends.
Despite gaps between the CGM and traditional meter, the DexCom still gives me the line, which means a lot. I'm constantly reminded that no matter what number I get with a fingerstick, I never have any idea which direction I'm going. Enter the DexCom, which gives me a line graph that quite accurately reflects whether I'm having an upswing, downswing, or a nice steady lull.
And luckily, my newest sensor seems to be more spot-on, so my smile's coming back. I even went swimming with it yesterday and it kept on tickin' right under the shower patch!
So what has my line graph done for me so far? (pictured above is an example only) A lot, actually. It's showed me where my "problem phases" lie. My post-meal results after breakfast and lunch consistently sucked. So I'm taking action: tofu and scrambled eggs for breakfast; earlier, more aggressive injections (no more waiting till I've cleared at least half my plate); and I've tightened my insulin-to-carb ratio a bit. And I can see -- in real-time even -- that my numbers are evening out!
The other thing to remember here is that a continuous monitor doesn't actually do anything to improve your glucose control; rather, it gives you valuable information about what you can do for better D-management. I'll let you know how it goes...