Closed-Loop System with Glucagon, Exercise and Mixed Meals
Research type
Research Study
Full title
Clinical Assessment of a Closed-loop System with Glucagon, Exercise and Mixed Meals
IRAS ID
156090
Contact name
Nick Oliver
Contact email
Sponsor organisation
Imperial College Healthcare NHS Trust
Research summary
The objective of the study is to assess the safety and effectiveness of a closed-loop system for type 1 diabetes which uses insulin and glucagon and comparing it standard insulin pump therapy (open-loop system). The closed-loop system will be assessed during and after an exercise challenge and different types of meals.
Glucagon is a hormone that has the opposite action to insulin and is used in the treatment of severe hypoglycaemia (low blood glucose). The closed-loop system using insulin alone has already been tested in 20 people with type 1 diabetes demonstrating safety. Adding glucagon allows the closed-loop system to safely set a lower blood glucose target without increasing the risk of hypoglycaemia.
The closed-loop system for this study consists of a continuous glucose sensor, a controller and two pumps (one for insulin and the second for glucagon). The system automatically adjust insulin/glucagon infusion rates to keep glucose concentrations as close as possible to the normal range without hypoglycaemia.
The glucose sensor that will be used throughout the clinical validation studies is a commercially available subcutaneous sensor which sits just under the skin and samples glucose concentrations every 5 minutes. The sensor is calibrated against capillary blood glucose (fingerprick tests) a minimum of 12 hourly.
The controller is a handheld unit which adjusts insulin and glucagon infusion rates. It is based on experiments which have demonstrated how the cells in the pancreas produce insulin and glucagon in people without diabetes.
The primary outcome of the study is percentage time spent in the glucose target range (3.9-10 mmol/L)and secondary outcomes include percentage time spent in hypoglycaemia (low glucose, <3.9mmol/L)and hyperglycaemia (high glucose,>10mmol/L).
REC name
London - Dulwich Research Ethics Committee
REC reference
14/LO/1187
Date of REC Opinion
27 Aug 2014
REC opinion
Further Information Favourable Opinion