Tandem T-Slim Control IQ - different modes
What happens if you use Control IQ Sleep Mode all the time? In a post from last year I compared non-closed-loop diabetes control with Basal IQ and Control IQ. Under Control IQ there are two modes - Sleep Mode and Normal Mode. Under Sleep Mode, if the glucose level is too high then the pump onoy increases the basal (background) rate to bring the glucose level down, whereas in Normal Mode, it will give discrete boluses to do this. Also, the target glucose ranges are slightly tighter compared to Normal Mode.
When I did the experiment in the last post, I used the pump in Sleep Mode all the time - not just at night. Since then I have been running the pump in Normal Mode during the day, and Sleep Mode at night. In this post I have crunched the data again to see which mode is better: Sleep Mode all the time, or Sleep Mode only at night.
I followed the same approach is in the previous post to generate the data.
Average glucose level
Looking at this image, the average glucose level is sightly higher using Normal Mode compared with Sleep Mode, but it’s still pretty good.
Time in range
Time in range is a lot worse when using Normal Mode, especially when too high. This agrees with the average glucose level being higher under Normal Mode.
Number of times woken at night
The number of times woken at night is much worse - in Sleep Mode I was hardly ever woken at night, but in Normal model I was woken 27% of all nights. This isn’t as bad as without Control IQ, but it’s still a lot worse than 0%! THe strange thing is that Sleep Mode would have been active during these hours. However, I was quite often high when going to bed, and so for the first couple of hours of sleep my glucose level would have been above the high threshold and therefore would have counted towards being woken at night, before the sleep mode had a chance to kick in.
Conclusion
It’s possible that last year was just a bad year for diabetes control - it often happens that diabetes control gets better or worse and the factors aren’t really understood. But the data definitiely indicates that my glucose control during the year when using Normal Mode was a lot worse than when in Sleep Mode. I don’t have anything to lose by putting it back into Sleep Mode and so I’m going to do this. I’ll repeat the experiment next January and see if my glucose control has got better again!