November 26, 2007
Question from Caldwell, Idaho, US:
Does an average carbohydrate load have an effect on one’s basal dose? For example, if a person eats higher amounts of carbohydrates for a few weeks than is normal for them and their basal need goes up, then lowers when the carbohydrate load goes back to their normal average and their basal need is reduced, is this a coincidence? Or, could carbohydrates really have an effect on amount needed for basal? How/why would that be?
That is an interesting question. There is no doubt that the total insulin for a day includes what we call basal and bolus insulin. There is also no doubt that the two insulins overlap. Some of the basal serves the meals and some of the bolus serves the time between meals. I sometimes remind patients, teens especially, that they do need rapid insulin even when the don’t eat (breakfast especially). They will just skip the morning dose of rapid acing insulin and find themselves high at lunch. Now, one could augment the morning basal (if pumping) but that’s what the bolus does when one “corrects” for the blood sugar.
Likewise, if you increase the total daily carbohydrates for a while, will the total daily dose increase and might some of it be basal? This certainly seems reasonable as you might get into trouble with hypoglycemia if you just give very large doses of rapid acting insulin. Smoothing with the basal would also be needed. When you then eat less, the overnight risk of hypoglycemia might increase if you left the basal alone.
I know we have all this “intellectual” energy over basal and bolus, but it isn’t just that simple, as you have discovered.