DexCom and Me Update: Managing Expectations

Today marks the close of Week One wearing the new DexCom STS wireless continuous monitor. I’m still enthusiastic, of course, but I’ve learned a few things, mostly about managing expectations. OrStudent_driver more specifically: Lessons in How CGM Can Help Us Now.


- a magic wand for transforming your glucose control overnight (obviously, our rational minds know this beforehand, but somehow the vague hope lingers)

- an escape from multiple daily fingersticks. You now need fewer, to be certain, but you do need to calibrate the DexCom at least twice a day, and need to take a fingerstick reading anytime anything really happens, i.e. prior to dosing insulin or whenever the DexCom shows a High or Low reading

- an actionable replacement for the conventional monitor (as per above). You have to be careful! So far I’ve seen up to a 40pt difference between the DexCom and the standard monitor, so you really don’t want to dose (especially not stack doses) based on the continuous readings alone — which the company and the FDA are both very clear about, though it sure is tempting

- a relief from the schlep-and-hassle factor of diabetes. In fact, you now have one more device (complete with cable and case) to carry around with you and fuss about. btw, the DexCom only interacts with the OneTouch Ultra meter at this point, so you’re forcibly switched to that model (which isn’t bad, as long as you’re good at getting a generous blood sample onto the strip all at once… I’m learning)


- an incredible new way to view and understand your own body’s reaction to all the relevant diabetes variables: different foods and physical activities, insulin doses, menstruation, sick days, etc. The trick is to be patient enough to start out by simply observing, rather than trying to react to everything you see on the nifty little CGM screen right away

- the first-ever effective tool for people with diabetes to get reasonable, personalized answers to the following key questions:

  • how long does it take until my insulin starts working?
  • how long is the insulin active in my body?
  • does this differ by time of day? (for example: am I more insulin resistant in the morning than in the evening?)
  • what do my favorite meals do to my blood sugar?

Again, this requires patience (so totaallly not my strong suit). But imagine having access to a (reasonably) accurate graph of your blood sugar patterns over the whole day — especially if you’re able to compare this to some records of what you ate and did that day. Now imagine detailed graphs for the last 2 weeks, 3 weeks, or even 6 weeks (even without the food records). How powerful is that?! According to the study results that DexCom has presented, within just a few weeks of using the device, patients spent 26% more time in the target range (80-140).

Personally, so far I’ve mostly been just watching the details as I bounce up and down. Interesting. And I actually was able to intervene and make corrections (after double-checking with the OneTouch) following breakfast and in the afternoon hours when I otherwise would not have been aware of the SUS (sudden unexplained surge). I hope and pray that this will translate into a lower A1c. That is the Big Idea, of course.

Look for my data observations — and more useful insights?? — coming soon.


14 Responses

  1. Kevin
    Kevin June 30, 2006 at 8:02 am | | Reply

    Great info.

    Look forward to reading more.


  2. Nick
    Nick June 30, 2006 at 12:00 pm | | Reply

    Great info., Amy. Much appreciate your comments. I do BG fingerstick profiles (at least three, one for breakfast, one for lunch, and one for dinner )each season. This tells me several things:
    (1) how long it takes for my BG to peak after eating a meal
    (2) how high it peaks

    These are basically checks to make sure my blood sugars are well controlled for all meals. I wait ten minutes between successive readings though, rather than five.

  3. Nick
    Nick June 30, 2006 at 12:02 pm | | Reply

    Forgot the 3rd thing!
    (3) to ensure my doses of regular and humalog insulins adequately cover what I eat.

  4. type1emt
    type1emt June 30, 2006 at 2:32 pm | | Reply

    did your insurance company cover any of it?

  5. AmyT
    AmyT June 30, 2006 at 6:33 pm | | Reply

    Type1: unfortunately not, except (I hope) for the visit to my clinic, which is where I go for treatment anyway.

  6. Megan
    Megan June 30, 2006 at 8:51 pm | | Reply

    I was just wondering what made you chose to use the dexcom when you aren’t pumping. It seems like if you are going to be hooked up to something you may as well pump too, plus I wouldn’t think the info would be as useful without pump to fine tune things better. But I know shots work well for some people.

  7. AmyT
    AmyT July 1, 2006 at 9:22 am | | Reply

    Hi Megan,
    For me, the pump is just another way to get the insulin in, which is not really my pain point. What’s more important is knowing when to intervene and correct.

    Also, considering how many times I’ve lifted my 3yr-old and had her little shoes banging and tangling with the DexCom Receiver (hooked to my belt), I am damn glad there wasn’t any tubing on me. An infusion site with tubing would have been yanked out multiple times by now.

  8. Lisa
    Lisa July 1, 2006 at 10:16 am | | Reply

    Re the pump. I use it and frankly it rarely gets yanked out (Maybe twice in four years)despite small kids being carried, and other yanks on the tubing. I am casual about it and just clip it on to my pockets or waistband without a case. I could never get the basal control I wanted with any of the long acting insulins-my base rates change too much over 24 hours plus my insulin daily requirements flucuate by quite a bit and the pump allows me to make corrections up or down to the basal amount sooner. But many people get great results from shots without some of the downsides of pumps. I am starting a DexCom unit this next week. I really want it for nighttime tracking. I already test 10 to 15 times a day so have a pretty good idea of what is going on but need more nightime info, exercise info without having to stop and check, and would like to pick up basal changes quickly when my needs are jumping up or down. Type one 35 years, pumping 4 yrs.

  9. AmyT
    AmyT July 1, 2006 at 2:09 pm | | Reply

    I’ve said it before and I’ll say it again: I’ll do the pump when I’m ready.

    Meanwhile, I’m taking Continuous Monitoring (and the notion of wearing a sensor attached to the body) for a test drive :)

  10. Lisa
    Lisa July 1, 2006 at 9:11 pm | | Reply

    My comments were not directed towards you, just general observations about me. I am interested in your DexCom experience because I will be using it next week and it will be fun to see how worthwhile it is.

  11. PrintCrafter
    PrintCrafter July 2, 2006 at 7:05 am | | Reply

    Pump or MDI; I predict that in five years CGM monitors in various flavors will be as common as BG meters are today.

    Thanks for Sharing, Amy, it is a great serivce to all of us!

  12. Diabetic Rebel
    Diabetic Rebel July 5, 2006 at 7:59 pm | | Reply


    I’m actually thinking about getting the Dexcom myself because I want to get pregnant and I think it would help me tremendously! On the other hand, I heard it’s pretty expensive and I saw in your answer that it’s not covered by your medical insurance. I hope in the future we will all be able to get access to these devices just as easy as a regular testkit.

    How long do you wear the sensors and do you wear it all the time? How easy is it to insert them?

    (I love your blog and I’m always excited to read your new postings, it is very helpful!!!)

  13. DMW
    DMW August 26, 2006 at 1:13 pm | | Reply

    Just finished a DexCom trial too – if this had been my first experience with the continuous glucose monitoring, I’d have been sooo disappointed. Found it so very inaccurate – most of the time. Anywhere from 30-60+points different. Repeatedly warned me I was low (50′s) when I wasn’t (80-90′s)… expensive sensors quit on me 24hours early…and although the company kindly offers to replace any that do this – come on. This should be a rarity not a “most of the time” incident. Being able to view only a 9hr max graph is frustrating as well. The download software for users should have been priority for the company, even before releasing this to consumers. It appears that the Dexcom system needs some work. Disappointing because the concept sounds so promising! I am a CDE as well, and can’t trust the DexCom enough to recommend it to my patients. On the other hand, my experience with the new Paradigm pump/sensor was entirely different & utterly fantastic! I found that to be extremely accurate & reliable. Just waiting on the insurance coverage to purchase that one.

  14. Gary Krauch
    Gary Krauch September 5, 2006 at 5:57 am | | Reply

    Diabetic Rebel writes:

    “On the other hand, my experience with the new Paradigm pump/sensor was entirely different & utterly fantastic! I found that to be extremely accurate & reliable. Just waiting on the insurance coverage to purchase that one.”

    Gary writes:

    CGMS with DexCom is definitely a “YMMV” (your mileage may vary) deal. Although I’ve only been on it for 2 weeks, I have not had the same experiences as diabetic rebel; the DexCom tracks my Ultra quite well.

    Note the following comments from the New York Times article on CGMS:

    “The main problem was that the sensor was simply not as accurate as a blood-glucose tester. MiniMed’s studies show the sensor’s accuracy can be off by as much as 18 percent. Another sensor, just approved by the F.D.A. and made by DexCom, is said by some researchers to be a bit more accurate, as is a third device, from Abbot, which has not yet been approved. But none are as accurate as a standard blood-sugar test.”

    This is from the August 29th article in the New York Times.

Leave a Reply