Type 2 Question:
Q: How do the pills for diabetes work?
A: The currently available pills (known as oral agents in the medical jargon) in the United States for the treatment of diabetes are all of the same class, Sulfonylureas, and therefore they all work the same.
They act to stimulate the insulin producing cells of the pancreas, the beta cells, to increase its insulin output for any blood sugar level. They do not work for patients with Type I insulin dependent diabetes because these patients have no functioning beta cells left to stimulate. They should not be used during pregnancy as they do cross the placenta and may be harmful to the developing fetus.
There are many different brands of Sulfonylureas, but these differ only in their duration of action-that is, whether they are taken once or twice, or three times a day-and in a few different side effects. If the blood sugar is not responding to one oral agent, it will not respond to a different brand. Although initially reported to have effects other than stimulating insulin secretion from the beta cells, it is now believed that these other “extra-pancreatic effects” are unimportant or do not occur at all.
Insulin & Exercise?
Q: How should I adjust my insulin and food intake during and after heavy exercise?
A: Although seemingly a simple principle-exercise lowers blood sugar-there are many nuances to this that make the actual management of your diabetes with an exercise program difficult. It is true that exercise will lower your blood sugar, provided there is insulin in your system. As a general rule, if your blood sugar is 250 mg/dl or less at the start of exercise, you can assume there is insulin “on board.” Exercise in this situation should lower your blood sugar. However, the rate and the time at which it is lowered depends a great deal on how vigorous the exercise is, when your last insulin injection was, and individual differences in response to exercise that are as yet unexplained.
You can probably count on about a 100 mg/dl drop per hour of exercise if you are starting with a blood sugar of 250 mg/dl or less. Usually this fall in blood sugar commences during the exercise and may continue for several hours afterwards. However, in some patients, the increased adrenaline brought about by the exercise actually counteracts this fall during the exercise period. Therefore, you may not notice a fall in blood sugar starting until two to three hours after your exercise is over. My patients relate just such a scenario to me. They say that their blood sugar is normal at the beginning of exercise, doesn’t change much immediately after exercise, but they become hypoglycemic several hours later when their muscles replete themselves of their spent glucose.
If the blood sugar is greater than 250 mg/dl percent at the start of exercise, you can assume that there is not much insulin “on board.” It is okay to exercise in this situation as long as you take some insulin prior to exercising. The same considerations concerning how quickly and when this blood sugar will fall as discussed above still apply.
You can see, because of all these nuances, things aren’t quite so simple. Self glucose monitoring has made things easier, however. I instruct my patients to measure their blood sugar before, immediately after, and several hours after exercise. They may adjust insulin accordingly. Generally speaking, a lower dose prior to or on the day of exercising, and a bigger snack after exercise is recommended. I have many patients run marathons and even triathlons. I am a firm believer in the benefits of exercise. Therefore, although some of these considerations may seem a bit confusing, they are all easily surmountable.