Nocturnal Seizures in an Adolescent With Type 1 Diabetes and Cross-Country
A 15-year-old with type 1 diabetes for 6 years has HbA1c 7.2% on insulin glargine 20 units at bedtime and insulin aspart with meals. He recently joined cross-country and practices from 5 to 7 pm. He eats dinner at 6 pm, then practices, and has had two nighttime seizures in the past month. CGM shows glucose 55 mg/dL at 2 am on practice days and 110 mg/dL on nonpractice days. He uses a sensor but not an automated pump. He wants to continue sports and asks whether he should stop insulin before exercise. His parents are afraid to let him sleep.
1. Explain the likely causes of nocturnal hypoglycemia on practice days. What regimen changes would you make?
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The timing strongly suggests exercise-related hypoglycemia. Cross-country practice from 5 to 7 pm increases insulin sensitivity for many hours, and a 6 pm dinner with a mealtime aspart dose followed by exercise can produce a delayed fall at 2 am. The bedtime glargine dose may also be too high on practice days. I would not stop insulin before exercise. Instead, I would reduce the pre-exercise aspart dose or give extra carbohydrate before and during practice, check glucose at bedtime, and consider a 10–20% reduction in bedtime glargine on practice days. A snack at bedtime may be needed if bedtime glucose is below target. The 2 am CGM value of 55 mg/dL is a true warning, so I would set a sensor alarm and review the glucose trend after practice. Changes should be made one at a time and reviewed with the family.
2. What safety education and monitoring plan would you provide?
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I would teach the family to check glucose before, during, and after exercise, and to check at bedtime and at 2–3 am on practice days. They should keep fast-acting carbohydrate and glucagon available, and the coach should know about the diabetes and glucagon use. I would review hypoglycemia symptoms and the possibility of impaired awareness after repeated lows. The teen should not sleep alone without a sensor alarm and a plan for a parent to check if the alarm sounds. I would emphasize that insulin should never be stopped completely, because that risks ketosis. I would also review driving safety and sports hydration. A follow-up in 2–4 weeks with CGM review would let us see whether the changes reduce nocturnal lows without causing daytime hyperglycemia.
3. When would you consider pump therapy or automated insulin delivery?
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I would consider pump therapy or automated insulin delivery if he continues to have nocturnal hypoglycemia despite regimen adjustment, if his family is willing and able to manage the technology, and if he wants more flexibility around sports. Automated insulin delivery can reduce nocturnal lows by adjusting basal insulin, but it does not replace carbohydrate intake or pre-exercise planning. Before starting, he needs a clear understanding of sensor use, set changes, and ketone monitoring. I would also address adherence and the family’s fear, because anxiety can lead to over-treatment of lows and rebound hyperglycemia. The decision should be shared with the teen, since he is old enough to participate in his own care.