Comparison of Closed-loop Operation After Morning Meal With and Without Carbohydrate Counting

Overview

Closed-loop strategy is composed of three components: glucose sensor to read glucose levels, insulin pump to infuse insulin and a dosing mathematical algorithm to decide on the required insulin dosage based on the sensor's readings. A dual-hormone closed-loop system would regulate glucose levels through the infusion of two hormones: insulin and glucagon. The main goal of this project is to assess whether a dual-hormone closed-loop strategy would alleviate the burden of carbohydrate counting from patients with type 1 diabetes (T1D) without a significant degradation in post-meal glucose control. Each patient will be admitted twice to a clinical research facility. In one visit, patients will eat a morning meal accompanied with a matching insulin bolus (depending on the carbohydrate content of the meal) and glucose levels will be subsequently regulated using dual-hormone closed-loop system. In the other visit, patients will eat the same meal but will inject only a partial insulin bolus (not depending on carbohydrate content of the meal) and the remaining needed insulin will be delivered based on glucose sensor excursions as part of closed-loop operation. If post-meal glucose levels were indifferent between the two visits, then this would suggest that carbohydrate counting may not be necessary during closed-loop operation as the closed-loop system will give any remaining insulin needed to cover the glucose absorbed from the meal. Twelve subjects will be enrolled in this study.

Conditions