November 23, 2003
Exercise and Sports, Insulin Pumps
Question from Suffolk, Virginia, USA:
I have had diabetes for five years, have been on a insulin pump for four months, and I teach dance four nights per week. I check 7-10 times per day, and I am having high glucose readings after exercise. I am following my meal plan so I am frustrated as to why I’m having these highs when I start out in range. Please help.
Because of the precise nature of basal insulin delivery with an insulin pump, it is not uncommon to observe elevations in blood sugar after certain types of exercise. The rise is a direct result of hormones such as adrenalin and cortisol, which are produced when exercise is of high intensity or is “anaerobic” such as sprinting, power-type activities, or even weight training might be. These hormones cause the release of liver glycogen, the stored source of glucose. Your dancing may be of a high enough intensity to produce the elevations that you are observing.
I am assuming that you are wearing your pump during exercise, and have not reduced or suspended the basal rates. Because of your pump, you do have a number of options available to you to prevent the blood sugar rise, including increasing your basal rates during (or mid) exercise via the use of the temporary basal rate function of your pump. Or you may simply bolus to correct for the highs after exercise, being cautious in your insulin correction factor due to the fact that both insulin sensitivity and energy metabolism remain elevated for a number of hours after exercise. Some insulin pump users also find that a pre-exercise snack and an appropriate or slightly conservative matching insulin bolus provide the right balance of both carbohydrate and circulating insulin to prevent the post exercise rise. Don’t forget to take a look at the meal prior to exercise, for any clues to its influence on your exercise blood sugars. The book, The Diabetic Athlete, by Sheri Colberg and Edward Horton, is an excellent resource as it provides a thorough explanation of the physiology behind diabetes and exercise. It may take some experimentation and continued vigilance in your blood glucose testing to find the right approach for your situation. Discuss these options with your diabetes management team before implementation.