My son has had pretty stable blood sugars at home, but, when he started school this year, his lunch time readings are very high (above 240 mg/dl [13.3 mmol/L] every day), and on weekends or days off he is not high. He is on 6 units of Humulin with 2 units of Humalog in the morning which was just raised by one unit, but he is still running high.

He eats a good breakfast according to his meal plan, and I even try to give more protein than carb. Could the protein be taking longer to convert and his short-acting insulin is done? Do you have any idea why he would be so high at school? The school nurse, our diabetes team and I can’t really figure it out.

It sounds as though you have a very good understanding of the various roles of food, insulin, and exercise for your son’s diabetes control. Of course we have no details, but a very good possibility in the difference between the glucose pattern before school started and now may be a subtle change in his activity (sitting at a desk in the morning may be different than his summer routine).

Your thought on his protein intake may be very valid also. Did he have this during the summer? Is there a mid-morning snack? If he takes Humalog with breakfast, he may not need the snack. If he does routinely snack in the morning, you may find that Regular at breakfast would be superior to Humalog. If he is not a snacker, then I think your immediate options are to either decrease the breakfast calories or increase the morning intermediate insulin, which I presume is NPH.

(As an aside, you described the other morning insulin as “Humulin.” Humulin is a brand name, the way “Chevrolet” is a brand name, but there is a big difference between a Chevrolet Suburban and a Chevrolet Corvette. There is a big difference between Humulin NPH and Humulin Regular.)

DS