The Current Status of Bolus Calculator Decision-Support Software

Abstract

The purpose of self-monitoring of blood glucose is to take action based on the results of the tests. The three actions that must be taken by insulin-using diabetes patients in response to blood glucose self-testing are, first, to record the blood glucose level, second, to calculate an appropriate dose of insulin, and, third, to administer the dose of insulin. A low-technology solution exists for each of these three actions. In addition, a commonly used high-technology solution exists for the first and third of these three actions (recording the blood glucose level and administering the insulin dose), but no high-technology product is currently approved by the Food and Drug Administration (FDA) for calculating an insulin dose (Figure 1). The currently unavailable high-technology approach to glucose-directed insulin dosing is approved software for calculating a bolus dose of insulin. Figure 1 Technology to apply to blood glucose data for administering an appropriate dose of insulin. In the first article to report a premeal bolus calculator was a system that was intended for use by insulin pump users.1 The bolus formula in that article incorporated five elements: (1) the carbohydrate/insulin ratio (carbo-hydrate bolus dose); (2) the insulin/carbohydrate ratio (correction bolus dose); (3) the target postprandial blood glucose; (4) the current blood glucose level; and (5) the carbohydrate content of the planned meal. The first four of these elements were known in advance and could be preprogrammed. Only the meal content would need to be entered at the time of the meal. Four factors that could affect the dose calculation, but were not accounted for, were as follows: (1) any correction bolus insulin onboard from a recently administered correction bolus insulin dose; (2) any carbohydrate bolus insulin onboard from a recently administered correction bolus insulin dose; (3) exercise either recently since the last dose of insulin or planned soon; or (4) any food onboard since the last dose of insulin. Accounting for these four factors could make for a more accurate bolus calculator to match a lifestyle, food, or physical activity choice with a correct dose.