Closed-loop Control of Glucose Levels After Meal Intake in Adults With Type 1 Diabetes

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 objective 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. Our primary hypothesis is that meal-announcement strategy (pre-meal CHO-independent bolus) is equivalent to meal-and-carbohydrate-announcement strategy (full CHO-matching bolus) during closed-loop regulation of glucose levels in adults with T1D. Our secondary hypothesis is that closed-loop strategy with meal-announcement strategy (pre-meal CHO-independent bolus) or meal-and-carbohydrate-announcement strategy (full CHO-matching bolus) is better than conventional pump treatment in regulation of glucose levels in adults with T1D.

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 dosages based on the sensor's readings. A dual-hormone closed-loop system would regulate glucose levels through the infusion of two hormone: insulin and glucagon. Each patient will be admitted three times to a clinical research facility. In the meal-and-carbohydrate-announcement visit, patients will eat 3 meals 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 meal-announcement visit, patients will eat the 3 same meals 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. In the control visit, patients will use conventional pump therapy to regulate glucose levels.