Diabetes, Exercise and the Brain

For the past two summers I have driven to Ithaca, New York, to take a five-day course at Cornell Adult University. Ithaca is at its best during the summer when the fog and weather do not interfere with the beautiful campus. Last year, I took a Jane Austen literature course. This year, due to the absence of British literature offerings, I took a seminar on "Memory and the Brain." It was taught by a PhD psychologist directed a group of 18 adults through the mazes of memory. Although his subjects were indeed rats (cute ones, actually), much of the material had direct application to humans because both our species share mammalian characteristics.

We spent five days learning about brain anatomy and different types of memory. Among the most striking things we learned was that exercise enables the growth and regeneration (neurogenesis) of certain neurons in the brain. Naturally, I began to wonder if exercise would also play a role in the development of new pancreatic islet cells. (As you know, the islet cells do regenerate, but are continually destroyed by the autoimmune process). Exercise also encourages the formation of new blood vessels (arteriogenesis) and therefore, in theory, probably enables growth and regeneration of other cells in the body as well. The key message is that exercise promotes many beneficial properties for human cells. Having said that, why does the mere mention of strenuous exercise provoke anxiety in many caregivers of children and teens with type 1 diabetes? With the fear of hypoglycemia, many children and teens are unable to participate in overnight camps, sports, and school excursions.

As the last few weeks of the summer vacation comes to a close, I would like to provide some tips to help with hypoglycemia avoidance. The goal is to have diabetes management fit into your activities rather than having your activities arranged around diabetes. It is so much easier said than actually done!

1. All exercise is not equal. Different activities may cause different patterns of blood sugars. Some activities that increase the stress hormones of epinephrine, etc., may actually cause blood sugar to increase at the onset of activity. This response may occur in association with the actual competitive event (football, basketball game, etc.). However, practice sessions may not provoke hyperglycemia initially and hypoglycemia may ensue up to 24 hours later. Therefore, it is important to determine how each individual reacts to different forms of exercise (practice vs. competitive event).
   
2. I would also suggest a "starting" exercise blood sugar goal, somewhere between 150-250 mg/dl depending on your unique response to exercise. It is important to consult with your diabetes team to determine your ideal pre-exercise blood sugar to avoid both initial hyperglycemia and hypoglycemia.
  
3. The type of insulin regimen may determine the method utilized to avoid hypoglycemia.
  
Conventional split mixed insulin with NPH/regular or analog (two or three shots/day):