Our little S (11yo) dx'd 18mth ago often has inexplicable drops, typically overnight between 12:00-2:00am (she goes to bed at 10). We have a CGM and have confirmed these drops with carefully timed night-time checks. I didn't initially believe it given how sudden the drops (and subsequent rises) were.
In the above screen shot, you can see how the pump suspended the basal automatically when it detected the hypo. Also, the tiny blue notch in the bottom half shows a bolus about 1 hr earlier of 0.3U. We have noticed this affect with no bolus or food for many hours before. However, 0.3U out of a TDD of about 25U shouldn't cause this?
Finally, in an effort to stop these hypos I've cut S's basal almost in half from 11:30pm until 2pm but it hasn't fixed the problem.
S is generally very variable and despite huge efforts we can't get much in the way of control. Any help would be very much appreciated.
If you want to affect the basal between the period of Midnight and 2AM, you have to change the doses earlier - say between 10 and 12 as it is about 2 hours ahead. I can't really explain why that is, but if you read Pumping Insulin it will explain it better. This is the formula with which I alter my own basals, always changing the rate two hours ahead of when I am having the problem and it works pretty well.
Zoe, thanks but I try to keep the basal reduction to as small a window as possible. In this case, I dropped to about 60% about 1hr 30m beforehand. If I make that window of reduced basal any longer, I get big rises for the rest of the night. J
Was S perhaps very active that day? Children can have what is called Post Exercise Late Onset Hypoglycemia (PEL), also called Late-Onset Hypoglycemia. It apparently is fairly common in kids. A good presentation on the topic is here.
ps. I have similar drops, about two hours after exercise, but have been able to stop them by eating a good meal after exercise.
bsc, thanks for the help and you may be onto something. S did exercise that day but about 12 hours beforehand. After that exercise, she had two meals. Could it really carry over till that much later? J
Oh, and suspending the basal when a hypo occurs is 1-2 hours too late. But take heart, suspending the basal probably won't help. PEL happens anyway, basically with almost no insulin. And PEL can occur at any time from 1-36 hours after exercise. In my case it happens 2 hours after exercise, but I am old and decrepit. In kids, it often occurs overnight.
bsc, thanks, that slideshow is good quality and I'll be re-reading it. You're right about the basal taking way too long to matter in those instances. It's useful to at least identify a likely culprit in this case but what might we do to avoid it? It's interesting to note that we found S didn't need much carbs to sustain her through the exercise earlier that day. Might it be the case that we need to set a very low basal for the first few hours of deep sleep to compensate for PEL on those 'exercise' days? Thanks for help J
We actually decided to use a pump basically just for this reason. We were finding that my son was going low during the night after having practice earlier in the evening. When my son (14 yrs old) has basketball practice we reduce his basal by 30% for 6 hours. Each type of activity requires a different reduction in basal depending on his level of exercise. We have also found that when he plays video games (he jumps up and down while playing them) we reduce his basal by 20% for 4 hours. Good luck!
