Closing the Loop in Adults With Type 1 Diabetes in the Home Setting
The main study objective is to compare real-time continuous subcutaneous glucose monitoring (CGM) combined with overnight automated closed-loop glucose control, and real-time CGM alone in the home setting.
Type 1 Diabetes Mellitus
Other: Conventional insulin pump delivery
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||An Open-label, Three-centre, Randomised, Two-period, Crossover Study to Assess the Efficacy, Safety and Utility of Real-time Continuous Subcutaneous Glucose Monitoring Combined With Overnight Closed-loop Glucose Control in the Home Setting in Comparison With Real-time Continuous Subcutaneous Glucose Monitoring Alone in Adults With Type 1 Diabetes on Subcutaneous Insulin Infusion Pump Therapy|
- Percentage of CGM (Continuous glucose monitoring) values in target (3.9 - 8.0 mmol/l). [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]Participants will be assessed overnight (00:00 to 07:00) for 4 weeks in each arm.
- Percentage of CGM values below 3.9 mmol/l. [ Time Frame: 4 weeks ] [ Designated as safety issue: Yes ]Participants will be assessed overnight (00:00 to 07:00) for 4 weeks in each arm.
- Time spent with glucose levels below 3.9 mmol/l and above 8.0 mmol/l, as recorded by CGM and other CGM-based metrics [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]Participants will be assessed overnight (00:00 to 07:00) for 4 weeks in each arm.
- Glycaemic control assessed by fructosamine and HbA1c [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]Participants will be assessed for 4 weeks in each arm.
|Study Start Date:||January 2013|
|Estimated Study Completion Date:||December 2013|
|Estimated Primary Completion Date:||December 2013 (Final data collection date for primary outcome measure)|
|Experimental: Closed loop (algorithm)||
Subcutaneous delivery of Novorapid insulin, dose calculated by control algorithm, based on continuous glucose sensor readings.
Other Name: Automated CL
|Placebo Comparator: Open loop||
Other: Conventional insulin pump delivery
Subcutaneous delivery of Novorapid insulin according to usual pump regime
Achievement of tight glycaemic control in type 1 diabetes mellitus (T1D) using intensive insulin regimens, which has been shown to be important for the prevention of long term diabetes-related complications, is limited by a significantly increased risk of hypoglycaemia. The average patient with T1D suffers two symptomatic episodes of hypoglycaemia per week, and one episode of severe hypoglycaemia, defined as an event requiring assistance of another person to administer rescue treatment in the form of carbohydrate and/or glucagon, per year.Despite the rapid advancements in insulin pump technology and the ongoing development of more physiological insulin preparations, the currently available therapeutic regimens are still unable to achieve optimal glycaemic control.The emergence of continuous glucose monitoring (CGM) over the last decade, which enables users to view in real-time estimates of plasma glucose and receive alarms for impending hypo- or hyperglycaemia, thus facilitating appropriate changes in insulin therapy, is a major step towards improved diabetes monitoring.
The desirable goal is the development of an insulin delivery that is glucose responsive and the development of effective real time glucose monitoring should allow this. Glucose responsive insulin delivery should allow achievement of ideal glucose targets with less risk of hypoglycaemia. Closed-loop systems may provide a realistic treatment option for people with T1D. The research we are conducting at the University of Cambridge has been focused on developing a closed-loop system for overnight glucose control in patients with T1D. The studies that have been performed so far employ model predictive control (MPC) - this algorithm estimates patient-specific parameters from CGM measurements taken every 1 to 15 minutes and makes predictions of glucose excursions, which are then used to calculate basal insulin infusion rates. We hypothesize that overnight automated closed-loop glucose control in the home setting will be efficacious and safe compared to CGM alone, in T1D subjects on insulin pump treatment.
|Cambridge, United Kingdom, CB2 0QQ|
|King's College London|
|London, United Kingdom, SE5 9RJ|
|Northern General Hospital|
|Sheffield, United Kingdom, S5 7AU|
|Principal Investigator:||Roman Hovorka, PhD, MSc, BSc||University of Cambridge|