Stretching Sensor Times

I saw somewhere where some people are pushing sensor times to 12 days. I was dismayed after upgrading to the Seven CGM, which was dumb since I own a company myself, that Dexcom doubled the price of their Seven sensors, that allow you to use it for 7 days instead of 3. You know it is the exact same sensor. They just got approval from the FDA for 7 days. Has anyone pushed the time to 14 days? That would be simpler for all.

My first pack of SEVEN Sensors performed very badly, not even getting 7 days each. But this one is on day 16 now, and showing hardly any “missed data” at all. I typically got 17-20 days on the old STS Sensors, so this one seems to be doing as well as before.

The most important thing for long Sensor life is to make sure that it doesn’t move within your body, NOT AT ALL. Stick it down firmly, and when the tape begins to give way at the edges (typically around day 12 for me) use Opsite Flexifix tape, or Mastisol liquid glue, or similar products, to keep the ENTIRE area of the original adhesive pad fixed firmly to your skin.

When the edge of the adhesive pad is failed, tiny amounts of movement are increased dramatically, even if it looks like the center and the Sensor are still in place.

And of course, a site which doesn’t have a lot of powerful muscular movement is good. Frontal Abs don’t work for me, right now, I’m lifting lots of HEAVY stuff while remodeling the house and building a new retaining wall in the back yard. But that site never did work for me, not even when I wasn’t doing these projects. I use “love handles” on the sides.

The last key is to keep from “burning through” the reagent too fast-- keeping your bG low, in a “healthy” range, is good for the Sensors. The reaction rates aren’t purely linear with bG, there’s exponential components in the curve-- so you’re burning up the Sensor way more than 3x as fast when your bG is at 300 mg/dL than when your bG is at 100.

But bG and reactants usually isn’t the limiting factor, I think-- it’s the microscopic motion, bothering your tissue and provoking IR response, which leads to end-of-life for Sensors. So the KEY is to keep it from moving around.

Wow! Thanks for the short course in sensors. I learned more from you in your reply than from others. Thanks again.

A belated Amen to your observation on sensor movement. I use the Dexcom 7, and am making new personal records every day now. Today I am on day 22, and the readings look just fine. I use 3M Medipore tape with one large BandAid to keep the sensor firmly in place, and since I am now 70 years old I don’t do much bungee-jumping or parachuting any more, and perhaps that helps.