I’ve had some issues with my blood sugars lately and it’s really starting to not make sense. While I was training for my first marathon (which I completed!!!) I purposely kept my blood sugars a bit higher before and during runs, but now they don’t seem to want to come down - ever. I just got back from three weeks in Europe, and as soon as I got back I took measures to really try and get blood sugars back to normal, but to no avail. And I don’t get it because when I take insulin for meals like my breakfast, which never changes, and which I know the exact carb ratio for, my BG still goes up a few mg. I usually have a granola bar mid morning, where again I know the carb count for and where before they never used to be an issue, but now they too shoot my BG up. And I think because I’m now stressing about it, that’s not helping either. Does anyone have any suggestions?
Have you tried a new batch of insulin? Perhaps it did not travel well.
also if you have reduced the amount of exercise you are doing this can have an effect on how well your body processes insulin. When you do more your body is able to use the insulin more effectively so you use less. If you have dropped some of that then maybe you need to increase your insulin amounts to cover the same amount of carbs. Also could be a change in temperature or altitude (and yes stress will have an effect too). If you really can’t work it out make an appointment with your health care professional 
Have you done any basal testing to make sure that is right? You might need more basal since you aren’t doing as much running. If your basals are off, your IC ratio could be off also. Like Heather mentioned, the cooler weather can cause problems also.
Congratulations on the completely your first marathon. I just my first half recently. Sherri Colberg has a book for diabetic athletes that you might find helpful. I agree with Heather that reducing the amount of exercise both per day and per week can change your insulin requirements. When you exercise a lot it increases your insulin sensitivity and over time even on days where you don’t exercise, but if there is a sustained break your lose that sensitivity over time (timing varies per person). The other issue which Dr. Colberg talks about is that as your body becomes more habituated and efficient at an exercise (running in your case) you can also scale back on some of the sensitivity you might have had when you first started. Like if you been running and then switched to/added kickboxing, you’d initially find that that kickboxing made you more sensitive to insulin than with running, but over time, it may not be as dramatic.
That’s all just exercise related but it seems like anything can cause a change in insulin needs over time including stress and hormones. Hope you can figure this out though
I agree with Heather, it could just be a decrease in training. While I’m most insulin sensitive immediately following a run, I will overall be more insulin sensitive for 24-48 hours after a run than when I take a few days off. The more I train, the more sensitive I become and my basal needs can change anywhere from 5-20% during the day.
Congrats on the Marathon! Wonderful goal!
Thanks everyone for your responses. I’m still fairly new in understanding the whole pump thing (even though I’ve had it already for 10 months) and when everything’s going perfectly for so long and then all of a sudden it gets turned upside down, it’s a little frustrating to say the least. But your responses were very helpful and gratefully appreciate them all.