Closing the Loop in Adults With Type 1 Diabetes

NCT ID: NCT00910767

Last Updated: 2009-09-17

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 12 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2009-02-28
• Study Completion Date: 2009-07-31

Brief Summary

The main objective of this study is to evaluate the feasibility of closed loop insulin pump therapy to improve overnight glucose control in adults with type 1 diabetes.

Detailed Description

People with type 1 diabetes(T1D) need regular insulin injections or continuous delivery of insulin using an insulin pump in order to keep the blood glucose levels normal. We know that keeping blood sugars in the normal range will help prevent long term diabetes related complications involving the eyes, kidneys and heart. However, achieving treatment goals can be very difficult as the tighter we try to control blood glucose levels, the greater the risk of the person developing episodes of low glucose levels (hypoglycaemia). This is a particular problem at night and one solution is to develop a system whereby the amount of insulin injected is very closely matched to the blood sugar levels on a continuous basis. This can be achieved by what is called a "closed loop system" where a small glucose sensor placed under the skin communicates with a computer containing an algorithm that drives an insulin pump. This system is being developed in Cambridge and we have trialed this on 16 children and adolescents with T1D in a clinical setting over the past year. We have found that this system is very effective at preventing hypoglycaemia in this group of patients.

We will recruit 12 adults with T1D on insulin pump therapy, and the studies will be done in a clinical research facility. The subjects will be studied on two nights. On one night they will have their normal insulin pump therapy and on the other night their insulin pump will be varied according to information about blood glucose values from the continuous glucose sensor. This information will be manually typed into the computer every 15 minutes from 8pm until 8am. The algorithm will advise of the insulin infusion rate and this will be manually changed by a trained nurse every 15 minutes throughout the night.

Conditions

Type 1 Diabetes

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Closed loop (algorithm)

Group Type: EXPERIMENTAL

Closed loop

Intervention Type: DEVICE

Subcutaneous delivery of Novorapid insulin, dose calculated by control algorithm, based on continuous glucose sensor readings

Open loop

Group Type: PLACEBO_COMPARATOR

Conventional insulin pump delivery

Intervention Type: DEVICE

Subcutaneous delivery of Novorapid insulin according to usual pump regime

Interventions

Conventional insulin pump delivery

Subcutaneous delivery of Novorapid insulin according to usual pump regime

Intervention Type: DEVICE

Closed loop

Subcutaneous delivery of Novorapid insulin, dose calculated by control algorithm, based on continuous glucose sensor readings

Intervention Type: DEVICE

Eligibility Criteria

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.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Cambridge University Hospitals NHS Foundation Trust

OTHER

Sponsor Role: collaborator

Diabetes UK

OTHER

Sponsor Role: collaborator

University of Cambridge

OTHER

Sponsor Role: lead

Responsible Party

University of Cambridge

Principal Investigators

Mark L Evans, MD FRCP

Role: PRINCIPAL_INVESTIGATOR

University of Cambridge, UK

Roman Hovorka, PhD

Role: STUDY_DIRECTOR

University of Cambridge, UK

Locations

Addenbrooke's Hospital

Cambridge, , United Kingdom

Countries

United Kingdom

References

Hovorka R, Kumareswaran K, Harris J, Allen JM, Elleri D, Xing D, Kollman C, Nodale M, Murphy HR, Dunger DB, Amiel SA, Heller SR, Wilinska ME, Evans ML. Overnight closed loop insulin delivery (artificial pancreas) in adults with type 1 diabetes: crossover randomised controlled studies. BMJ. 2011 Apr 13;342:d1855. doi: 10.1136/bmj.d1855.

Reference Type: DERIVED

PMID: 21493665 (View on PubMed)

Other Identifiers

08/H0308/297

Identifier Type: -

Identifier Source: org_study_id