Monday, December 5, 2011
Precision: Matching Carbs to Insulin
How can we get more precise control over blood sugar? We've been experimenting with a way that seems obvious but I haven't seen mentioned anywhere: Match the carbs precisely to the insulin dose.
For example, suppose Karl is going to sit down to a lunch of 51 carbs, for which, at 15 carbs per unit of insulin, he's supposed to get 3.4 units of insulin. Well, we can't give him 3.4 units. We can give him 3.0 or 3.5, but not 3.4.
Because giving too much insulin is worse than giving too little (since giving too much leads to low blood sugar and the troubles that it causes, from hunger to fuzzy-mindedness to loss of consciousness), we round down, and Karl would get 3.0 units, which is four-tenths of a unit short of what he needs. We'd expect his blood sugar to end up about 40 points too high because of this.
On the other hand, if he had 52.5 grams of carbs, that would work out to exactly 3.5 units, so we could be right on the money. All we need to do is find 1.5 grams of carbs in a Karl-friendly package. What we use are Ritz Bitz, which come out to about 1.5 grams each. Problem solved!
So now he's getting anywhere between zero and four Ritz Bitz with every meal. It seems to make a real difference when his carbs are just short of the next insulin increment.
If you're using an insulin pen but aren't using one that allows half-unit dosage, you should be! The NovoPen Junior has been working very well for us. If we had to give insulin in one-unit increments, the number of Ritz Bitz we'd give Karl per meal would go as high as nine! He'd like that, but we wouldn't.