Lots of ? readings from sensor

I’m wondering if anyone has been getting lots of ??? readings while their blood sugars are rapidly rising or rapidly falling. It seems I do and I’m wondering if it is the sensor or if it really gets that confused?

So far, I love the Dexcom. It has awoken me up when my sugars are low and has allowed me to fine tune my basal rate on my Animas 2020. It seems I go low between 3 and 4 am. One night it caught a 39 - but I’m also beginning to question the accuracy of my One touch Ultra Smart. I don’t think it is smart anymore.

Hey Susan,

Its typical of Dex to give you ??? readings while your BG is rising or falling rapidly. Its not the sensor its just something that happens…I was told NOT to calibrate while getting the ??? it will confuse the sensor even more.

And I’d be careful when questioning the accuracy of your UltraSmart…Dex is not actually measuring your blood glucose its measuring your interstitial fluid (spelling im not sure) therefore your finger sticks are way more accurate than Dex - with that in mind I’m sure your doc, and even the people at Dex, would tell you not to treat yourself based on Dex’s readings to do a prick and treat based on that.

Dex is really supposed to be for watching trends NOT as a substitute for pricking. :slight_smile: Hope that helps!

HI Stacey-

Yes - this si helpful.

No - I would never treat based on my Dexcom. When I get the low alerts at night I always check with my UltraSmart. Although lately I am questioning the One Touch strips. I know I don’t have the recalled strips, but I am getting alot of lows lately and if the Dexcom is calibrated based on those readings, then I am questioning the accuracy of both devices. I know that the Dexcom number is going to be lower by a bit because it is interstitial fluid.

I’m thinking about getting my One Touch checked against a lab result and also at the same time checking the Agamatrix Keynote.Agamatrix claims that their meters are more accurate, so I’d like to see. If we find it measures close to the lab result, then I am going to calibrate the Dexcom with it and see what happens.

Also, your Dexcom lags about 20 minutes behind, whether high or low. As for the ?'s, I tend to get more in the beginning, or when the sensor is dying out, but yes, you will get them if you are moving up or down quickly. It’s as if it is questioning what is going on. Are you new to the Dex?

Hi Toni -

Yes - I’m fairly new to the Dexcom. I did a trial for the local diabetes clinic and loved it. Insurance approved it. I also trialed a Medtronic CGMS for them too - but the sensor was a little uncomfortable.

I love the Dexcom! It is fun to watch the trends and it has been helpful in figuring out where at night I am bottoming out. I’ve got my basal rate down to .275 on my Animas pump starting at 12 am and then I slowly raise it to cover DP. It has really given me some valuable insight into what is going on…

Hi Susan

If you dont mind me asking, what insurance company do you have? I have Capital Blue Cross and they are absolutly refusing to pay for the sensors unless: You are pregnant, or you have a history of severe hypoglycemia unawareness. Its so frusterating but there is nothing i can really do. Did you have to fight at all with your insurance?


HI Brian -

I have United Health Care. They don’t always pay 100% for it - it depends on your employer’s plan. But they seem to cover it even not at 100%. Some UHC plans seem to pay for it at 70-80% - but they are paying for it.I was actually shocked but thought it was worth a try. It was quite easy too. I guess UHC is with the program, so to speak.

I had to give Dexcom/insurance a month’s worth of blood sugars. I gave them a printed out copy of my Animas pump/One Touch blood sugar log. I have been having lots of lows at night and not being awoken by symptoms so I can treat them. I also sometimes have severe lows in the morning after breakfast. Sometimes I can go up over 200 or 300 but end up 50. I’ve tried different strategies to prevent the rise and the lows. I have finally mostly figured it out so that I am under 180 most days after breakfast - and am starting to figure out how to prevent the low many hours after - without having to eat something. The CGMS data has helped me to figure it out.

History of nocturnal hypo events is an indication that DEFINITELY works in insurance fights. Also, if your A1c is above 6.5 or so, you can now use the NEJM/JDRF study for T1 adults (published in September), it thoroughly destroys the old, widely used argument that “CGMS doesn’t improve control as measured by A1c”.

Did Capital Blue Cross give you a “policy” reference?