Several members have posted about unusual BG and insulin behavior over the last month or so -- I'm seeing something else in the last two weeks that's kind of strange.

I have a Dexcom G4 CGM. After 6 months with it, I've got a pretty good "feel" for how my BG reacts to different foods, carb amounts, glycemic index, and insulin.

I rarely, if ever, get the single or double up-arrow indicators showing rapidly changing (up or down) BG. Almost always the angled up or down arrow when it's rising or falling.

Yet, in the salt two weeks, my BG seems to be much more volatile for some reason. I haven't changed anything -- eating the same, administering insulin the same in quantity, timing, technique -- but I'm getting rapid rise/fall almost at least once a day. Over the weekend, it was almost any time I did anything that affected my BG.

Note that my control hasn't gotten worse -- I'm not swinging up to big highs, or having increased hypos. It's just that the swing after eating from 90 or so to 140-150, and then the fall back down a few hours later is happening much more steeply, and over a shorter time period.

Anyone have any idea what's happening? I'm T2, and I'm wondering if my insulin resistance is getting better, my beta cells are just now showing some revitalization after being given a break over the last 6 months, or...

I'm going to fiddle with my ratios and other stuff over the holiday break (when I can keep a close eye on things), and see if that provides any revelation.

I gotta say, though, the much quicker fall after eating looks suspiciously like improved sensitivity from a T2 perspective...

Have you done any corresponding fingersticks to verify the accuracy of this rise and fall? I'm suspicious that something else may be going on. Someone commented here recently about dehydration affecting the sensor performance. I know I drink a lot of coffee and that can dehydrate.

You're posing a good question. I don't think that non-D (and non-insulin resistant) BG rise and fall is very rapid. A typical non-D BG line moves within a very tight envelope and therefore doesn't have much room to rise or fall rapidly for very long.

Are you using less exogenous insulin and getting better results? Or even using the same amount of injected insulin and getting better results would suggest that you're becoming less insulin resistant.

When my control is good, my Dex CGM line does not move quickly. I often rise and fall slowly on the sideways arrow and sometimes move to the angled arrow but seldom to the single or double down/up.

Isn't it great to have the CGM to watch how your metabolism responds?

I have that from time to time, though not so much lately. Most of the time, my BG, lie yours, does slow rise or slow falls; however for a period of a short time over the summer, I had double-down-arrows occasionally after my BG was somewhat higher than usual. I attributed it to a burst of internal insulin (I am also T2); however, I have no proof of that. This change has since stopped. Now, I only see the up or down arrows if I had a particularly high-carb meal or if I took a bolus and forgot to eat (or waited too long) - or during more intense exercise - Otherwise, I'm back to the slower rises and falls, as before.

Hmm, that's interesting. Maybe the CGM is "gaming" you, or you are gaming it, trying to push things? Even little "nudges" with extra carb counts, etc. can make a pretty big difference for me and perhaps you are doing that somehow?