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Closing the Loop in Adults With Type 1 Diabetes in the Home Setting

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01440140
Recruitment Status : Completed
First Posted : September 26, 2011
Last Update Posted : January 29, 2014
Diabetes UK
Information provided by (Responsible Party):
Hood Thabit, University of Cambridge

Brief Summary:
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.

Condition or disease Intervention/treatment Phase
Type 1 Diabetes Mellitus Other: Closed-loop Other: Conventional insulin pump delivery Phase 2

Detailed Description:

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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 24 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (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
Study Start Date : December 2012
Actual Primary Completion Date : December 2013
Actual Study Completion Date : January 2014

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Diabetes Type 1

Arm Intervention/treatment
Experimental: Closed loop (algorithm) Other: Closed-loop
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

Primary Outcome Measures :
  1. Percentage of CGM (Continuous glucose monitoring) values in target (3.9 - 8.0 mmol/l). [ Time Frame: 4 weeks ]
    Participants will be assessed overnight (00:00 to 07:00) for 4 weeks in each arm.

Secondary Outcome Measures :
  1. Percentage of CGM values below 3.9 mmol/l. [ Time Frame: 4 weeks ]
    Participants will be assessed overnight (00:00 to 07:00) for 4 weeks in each arm.

  2. 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 ]
    Participants will be assessed overnight (00:00 to 07:00) for 4 weeks in each arm.

  3. Glycaemic control assessed by fructosamine and HbA1c [ Time Frame: 4 weeks ]
    Participants will be assessed for 4 weeks in each arm.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Type 1 diabetes, as defined by WHO for at least 6 months or confirmed C-peptide negative.
  • On insulin pump therapy for at least 3 months

Exclusion Criteria:

  • Non-type 1 diabetes mellitus
  • Any physical/psychological disease likely to interfere with the study
  • Taking medication likely to interfere with interpretation of the results
  • Known/suspected allergy against insulin
  • Patients with clinically significant nephropathy, neuropathy or retinopathy as judged by the investigator
  • Ongoing severe recurrent hypoglycaemia as judged by the investigator.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01440140

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United Kingdom
Addenbrooke's Hospital
Cambridge, United Kingdom, CB2 0QQ
King's College London
London, United Kingdom, SE5 9RJ
Northern General Hospital
Sheffield, United Kingdom, S5 7AU
Sponsors and Collaborators
University of Cambridge
Diabetes UK
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Principal Investigator: Roman Hovorka, PhD, MSc, BSc University of Cambridge
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Hood Thabit, Clinical Investigator, University of Cambridge Identifier: NCT01440140    
Other Study ID Numbers: ANGELA03
First Posted: September 26, 2011    Key Record Dates
Last Update Posted: January 29, 2014
Last Verified: January 2014
Additional relevant MeSH terms:
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Diabetes Mellitus
Diabetes Mellitus, Type 1
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Autoimmune Diseases
Immune System Diseases
Hypoglycemic Agents
Physiological Effects of Drugs