Type 1 Nightime Highs - Unsure what is causing them?

Have you tested the high bg with a finger prick?
A Cgm is not as accurate so if I ever get unexplained Cgm reading I check.
Your son's experience is strange so I would be ruling out Cgm problems before changing insulin.

There is something called dawn phenomenon DP, it's a hormone release that almost always occurs before you wake. I have that every night to some degree and off and on it will for some strange reason hit at 2 or 3 in the morning. But it usually doesn't come down on it's own, you usually have to have more insulin. And it commonly wouldn't hit that early.

But I am wondering if it could be some kind of hormone signal? I'm not sure what age your son is, I'm not sure it would matter if I knew anyway, because I don't know what age hormones might play a part? I would post it in the parents forum too, maybe one of them has run across it.

The other possibility is different insulins peak at different times, so it could be the timing of the doses?

On page 12 it compares the curves of some of the different insulins
https://www.jdrf.org/illinois/wp-co.../2017/02/The-Insulin-Curve-JDRF-T1N-FINAL.pdf

I hope someone can help more!

Hi there, There have been posts with similar experiences to you with Tresiba causing overnight highs. The suggestion appears to be to split the dose. I hope you sort this issue out with your consultant soon.

https://www.diabetes.co.uk/forum/threads/high-blood-sugars-on-tresiba-degludec.132023/

Hi @Kayleigh1008,
Thank heaven for cgm when it works!!
The information provided about insulin curves by @Marie 2 could help explain somethings.
Based on past experience as a TID, not as medical opinion or advice:
1) Your son's Novorapid insulin, injected around half 5, effect is running out by half 10 pmish (according to the graphs mentioned by @Maree above).

2) Assuming he is eating his dinner about 6 pmish, you are recording a post meal BSL at 8 pm, 2 hours after food of between 6 and 9 mmol/l

3) as @Knikki points out the type of food eaten at 6 pm might still be causing a rise in BSL at the 2 hours mark and thus BSls have not reached its peak - and maybe this explains at least in part of the continual BSL rise seen at half 9 to 10 pm and after

4) also by 10 pm or so as mentioned in 1) above the Novarapid's effect may have fizzled out so there may not be sufficient insulin available to keep the BSL rise from continuing up.

5) there may be some low level effect of the Tresiba, long-acting insulin working from the injection he had the previous evening but even when the new injection of Tresiba given at 10 pm starts to work there is only a lowish level of insulin available to cope with any BSL.

6) whether this Tresiba insulin given at 10 pm is sufficient to enable the BSL to return to 4 to 6 mmol/l by 4 am (which is often quoted as the usual but not definite time of onset of the Dawn phenomenon)* is unclear. But I imagine you would not wish his BSL to be below 4 mmol/l at night!

7) seeing what his BSL is on waking may give some idea of whether there is an effect of the Dawn Phenomenon* happening.
His doctor could help you with that.

8) the problem with insulin curves is that they tend to show the average onset peak effect etc, NOT the ranges. I could not find figures for Novorapid but the table below shows the variation in onset, peak effect and fizzzle out of another short acting insulin. Of course one cannot make a direct comparison with another insulin but it does show that we can be misled if we stick to the average or usual figures.



9) Also: the peak effect and onset and duration (fizzle out time) of an insulin does depends on the dose given. A child needs less insulin weight than an adult on a scaled up diet. So child's lower doses may not last as long as in an an adults on the same insulin. See the graph below:



I cannot pretend to have explained along with @Marie 2 and @Knikki your son's BSLs but please discuss these things with his doctor to see whether that helps.
Best Wishes.

@Kayleigh1008 some great thoughts above.
I wanted to add one more: what is bed time like for your son? Is it a difficult time?
I ask because stress can cause BG to rise.

Just a thought although I am not sure why his BG would then fall afterwards.

Honestly, getting a pump along with the dex6 may help. (D1) You can program it for special hours of more or less insulin. The tandem pump works well with the dexcom. The readings come straight into the pump, although usually sent first to either the dexcom device or mobile.
I had such lows at 3 am that I just didn’t feel safe going to sleep before then. Like your son, I would get night time highs. So getting a pump where the basal insulin is dropped and easily changed, was ideal, and getting the dexcom meant that I could monitor enough to see exactly when my sugars would drift up (had a broken back and also was told I needed a shoulder replacement; chronic pain always shows up as increased blood sugars)
Yesterday I just had a trial shoulder nerve block with steroids. I couldn’t do that before I had both pump and CRM.
One of my students at uni is also type 1. After talking to me, his folks are about to get a pump etc for him....