Question from Mississauga, Ontario, Canada:

My child with type 1 takes exactly the same amount of rapid acting insulin (2 units of NovoRapid) before breakfast, lunch and supper which is 8 a.m., 12 p.m., and 6 p.m. Her blood sugar test before lunch is mostly good (6 to 8 mmol/dl [108 to 144 mg/dl]), before bedtime check (9 p.m.) is also good, but her before supper test (6 p.m.) is always high (about 12 mmol/L [216 mg/dl]). We suspected that the before lunch insulin was not enough, so we tried to increase it, but it didn’t help. Then, by chance, what we found actually was that her blood sugar was dropping to about 4 mmol/L [72 mg/dl] at 3 p.m. and then quickly rising to about 12 mmol/L [216 mg/dl] by 6, so it looks like to be a bounce after being low. But, I don’t understand why this low then high doesn’t happen after breakfast and after supper. The amount of insulin and carbohydrates from food are almost exactly the same; the only thing different after lunch is that my child sleeps from 1 p.m. to 3 p.m. every day. Will this impact blood sugar level?

In addition to NovoRapid before all meals, my daughter gets 1.5 units of Lantus in the morning. I considered splitting her Lantus dose but I was concerned about the higher blood sugars my daughter experiences at 9 p.m. (5 to 8 mmol/L [90 to 144 mg/dl]) and at 1 a.m. (around 15 mmol/L [270 mg/dl], but sometimes as high as 20 mmol/L [360 mg/dl]) followed by a drop to around 5 mmol/L [90 mg/dl] when she wakes at 7 a.m. On occasion, she is between 3 and 4 mmol/L [55 and 72 mg/dl] so we give her juice or milk right away. Are the roller coaster blood sugars because she is only 16 months old? She was just diagnosed three months ago.