A little before 11:00 pm, I got the buzz alerting me to a breach of the low threshold. I was tired and really didn't want to get out of bed to find some juice. I'm embarassed to admit it, but all I did was turn off my basal delivery for an hour and a half, hoping that would counter the insulin on board, and I would magically sleep through the night without going low. Well, you can see the result. Around 1:30 am, I got the buzz telling me I was headed up. I think the high peaked at about 240.
Why am I sharing this? Two points. One, this is a great example of the Dexcom doing its job. One of my motivations for buying this thing was the increasing number of mornings I woke up over 200. Without this monitor, I probably would have slept through the whole rollercoaster ride. I would have gone low without realizing it, and I would have rebounded without realizing it, waking up hours later with a high blood sugar and no idea what had happened. Without the high threshold I would not have taken a correction insulin dose at 1:30, and might have peaked even higher, certainly for much longer, before I woke up.
Dexcom also did its job alerting me in plenty of time to avoid the low in the first place, which brings me to the second point. One big problem about diabetes that is probably common to many chronic conditions: it's easy to get complacent, and having the CGMS doesn't magically protect me from extreme blood sugar swings. I feel silly needing these occasional reminders, these SUEs, that simply being alerted to a low isn't enough - I still have to be in charge, even when I'm too tired. I don't know if non-diabetics can understand, and I hope I'm not the only one out there who does things like this.
I also hope after posting this that no one shows up at my door and revokes my license to practice intensive insulin management. Turning off my basal delivery - what was I thinking? Next thing you know it will be Regular and NPH for me, just like in the dark ages. Nooooooo!
The main point is: thanks Comrade Dex for doing what you're supposed to. I dropped the ball. Nice textbook example of a rebound hyperglycemia though.