My blood sugar reading is lower when I go to bed than after an all night fast. Is this normal? What can be causing this?

The phenomenon you describe is very common. Low blood sugar after eating generally results from too a large dose of insulin for that given meal (i.e., dinner) while the next fasting blood sugar is sustained mainly on the liver’s of glucose during the night. This is called the dawn phenomenon. It’s caused by counterregulatory hormones (cortisol, growth hormone) released over the early period of the night (from about 12:00 midnight to 3:00 am) that subsequently activate the hepatic gluconeogenesis (de novo production of sugar by liver). If you go to bed with too a low blood sugar this will often potentiate the dawn increase in blood sugar. Try to go to bed with a little bit higher blood sugar and see whether this stabilizes your fasting blood sugar.

MS