My 10-year-old has had type 1 diabetes since April 2007. Her last A1c was 5.8%. She uses an insulin pump, a Paradigm Real Time with Continuous Glucose Sensor. Currently, she uses Humalog, about 17 units per day of basal and about 16 units per day for meal boluses. She weighs about 35 kg (77 pounds). Her glycemic situation is pretty good, with some exceptions. Periodically, in fact, after a few weeks of good glycemic control, there are some periods, like now, when, without much change in lifestyle and diet, her mid-afternoon and late evening blood glucoses suffer a sharp upturn, very strong, even in the presence of a normal blood glucose two hours after a meal. In fact, about three hours after the meal, her blood sugar level begins to rise, more or less abruptly, even reaching values 200 mg/dl [11.1 mmol/L] in less than an hour, unless we give a correction bolus. Of course, in these cases, we adjust the basal insulin with appropriate increases, often very strong. In these two time periods, my daughter needs a very high dose of insulin compared to other times of day (e.g., from 10:30 a.m. to 1 p.m. 0.20 units/hour because she tends to go “low” at lunch; from 1 p.m. to 5:30 p.m. 1.60 units/hour; from 7:30 p.m. to 8:30 p.m. 0.40 units/hour; and from 8:30 p.m. to midnight 1.40 units/hour). In your opinion, what could be the cause of such a phenomenon? Is there an alternative solution? There is a limit beyond which injected insulin becomes “excessive”?

You described the amount of basal insulin that your daughter receives per day; you also relayed the total amount of bolus insulin doses your daughter receives per day. But, you did not describe the ratio of insulin to carbohydrates that she receives for those mealtime boluses (or boli).

The after meal highs that you describe suggest to me that she needs an increase in her ratio of insulin-to-carbohydrates at the lunchtime and/or afternoon snacks. You seem to suggest that you address these higher glucose readings by increasing the basal dose. Did I understand that correctly? I would rather suggest that you give a “correction bolus.” There are other questions on this forum that address this but you should also check with your daughter’s physician as to his/her recommendation about a correction formula.

Another thought is to consider a different type of bolus pattern with your daughter’s pump. The bolus can be given as a “spike” whereby all the dosed insulin is given at once; it can also be given as a more sustained effect, (a “square wave” whereby the increased dosed insulin is given over a longer period of time; a combination or “dual wave” pattern is also available, whereby the bolus dose is given with part as a “spike” and the remainder of the dose as a “square.”) Different types of meals seem to do better with different types of bolus wave patterns. For example, a meal of primarily sweet, sugary items, might be better with a spike; a meal of primarily starchy carbohydrates (like pasta?) or lots of small bites (such as a buffet or even tapas) might be better with more of a square. But, the dual wave might be better for a “mixed meal” with fat. Again, talk to your daughter’s pediatric endocrinologist to determine what you should do.

DS