One of the interesting things that I deal with is a rise in blood glucose overnight. I go to bed with a BG of 84 mg/dL (last night), and wake up with a BG of 104 (this morning)! My last meal was about 12 hours ago so what happened?!
This can be the results of two different processes: Dawn Phenomenon and Somogyi Effect.
The dawn phenomenon is a natural part of our bodies circadian rhythm. The evolutionary process developed this so that our ancestors could get up in the morning after a night of fasting and have enough energy to find food. This is great ability to have when your food can run away ( think woolly mammoth ) but not so great when you just need enough energy to open the refrigerator.
The Somogyi Effect is caused by the bodies response to night time hypoglycemia. When BG drops overnight the body reacts by secreting a hormone, glucagon, which signals the liver to start converting stored glucose (glycogen) into glucose. This of course raises your BG.
I notice that my before breakfast morning BG is always higher (about 20 points higher) than my bedtime BG. I believe it's the dawn phenomenon at work. Have you experienced either the dawn phenomenon or the Somogyi Effect and how have you controlled it?