We have always seen a lot of variability in both Correction Factor (CF) and Insulin to Carb Ratio (ICR) when my son’s basal needs change. Possibly because we are looking at it so carefully, we are now noticing significant changes in both CF and ICR without basal changes.
For once, my son’s basal needs have been fairly stable for the past 3 weeks, even with changes in training regimen. But we have seen, over the past two weeks, a radical change in CF and ICR. His CF has decreased by a factor of two: he needs half the insulin he needed before for an average peak correction. Because these corrections are normally very large, the difference is quite significant. For something that may have needed 15 units 2 weeks ago he may only need 7-8 units or less right now.
Similarly, the ICR has changed, in the same direction, but nowhere near in the same ratio. If he was 1:13 at dinner, he may now be at 1:17.
We are trying to link this change to something concrete. His exercise level has gone up a bit, and is a bit more regular. It is possible that this may be the reason. But the difference is not major, so we are not sure.
The most unusual part of it, for us, is that this change did not come with a change in basal. We checked to make sure that it is not simply a tolerance in the basal insulin levels. When we decrease basal insulin by 10%, he does trend high, and when we increase basal insulin by 10%, he does trend low. So his basal need is truly unchanged.