For the past couple of months we have been fighting late evening (midnight) lows.
We have been trying many different hypotheses. One that I pursued for a long time was a Lantus activity peak 3 hours after injection – and it is possible that this may have contributed.
I did not think these lows could have anything to do with dinner ICR, because it was so late after dinner, although still within my son’s DIA (which is 5.5 hours): the high activity period of his insulin shuts off about 2 hours and 15 minutes after injection. So I never expected that it could cause sustained lows 4-5 hours after injection (sustained here means needing 15-20 carbs).
Well, for the past week we finally tried changing his dinner ICR by a fairly large percentage, and it looks like his evening low is gone (and he is not running high). We will know for sure in a few weeks. But, based on this, it seems that it is possible to have regular lows caused by the very tail end of insulin DIA.
We have been very focused on activity level for our insulin use. I am thinking this may have blinded us to the risks associated with the late, low-activity phase of an insulin bolus.
For the past several weeks as I’ve been titrating my Tresiba dosage I’ve been having 3:30am lows on a regular basis. I’ve been continually lowering the basal dosage, but the early morning lows persist.
Dinner bolus is usually around 7pm and I’ve never even considered that eight hours later it could drive me low. But after reading your post I’m going to adjust my dinnertime C/I and see what happens.
I have experienced this as well, but later in the afternoon after eating lunch. Similar time frame too - 4-5 hours after eating. It’s a bit odd, so I’m curious to hear more.
I experienced this just last night: timing was off or carb estimate, I spiked after dinner until the bolus kicked in…and then trickled down for the next several hours (beyond the DIA) so that I had to take in a few carbs at 3 a.m. So glad I did not give myself a little more insulin when I first spiked!