Closing the Loop in Children and Adolescents With Type 1 Diabetes in the Home Setting

Summary

Type 1 diabetes (T1D) is one of the most common chronic childhood diseases requiring lifelong insulin therapy. Children and adolescents with T1D need regular insulin injections or the continuous insulin delivery using an insulin pump in order to keep blood glucose levels normal. We know that keeping blood sugars in the normal range will help prevent longterm 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 to develop symptoms and signs 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 controlled by a computer and is very closely matched to the blood sugar levels on a continuous basis. This can be achieved by what is known as 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. We have been testing such a system in Cambridge over the last five years in children and have found that this system is effective at maintaining tight glucose control and preventing nocturnal hypoglycaemia. More recently the system has been tested in real life conditions in the home setting for three weeks during a pilot single-centre study.

The next step is to extend the evaluation of closed-loop over a prolonged period of three months. In the present study we are planning to study 24 young people aged 6-18 years on insulin pump therapy. During three months glucose will be controlled by the computer and during the other three months the subjects will make their own adjustments to the insulin therapy using real-time continuous glucose monitoring.

We aim to determine the effect of the computer algorithm in keeping glucose levels between 3.9 and 8 mmol/L (normal levels). Safety evaluation comprises assessment of the frequency of severe hypoglycaemic episodes. Participants' response to the use of the system in terms of lifestyle change, daily diabetes management and fear of hypoglycaemia will be assessed. We will also test for longer term glucose control by measuring glycated haemoglobin (HbA1c).

Conditions

• Diabetes Mellitus
• Diabetes Mellitus, Type 1
• Glucose Metabolism Disorders
• Endocrine System Diseases
• Autoimmune Diseases

Interventions

DEVICE

Overnight closed-loop

The closed-loop system is purpose-built and comprises a hand-held computer containing a model predictive control (MPC) based glucose control algorithm and communicating with the CGM device and the insulin pump.

DEVICE

Real-time CGM alone

Subject glucose level controlled by usual insulin pump therapy in conjunction with real time continuous glucose monitoring (CGM)

Sponsors & Collaborators

• Cambridge University Hospitals NHS Foundation Trust

  collaborator OTHER

• University College London Hospitals

  collaborator OTHER

• The Leeds Teaching Hospitals NHS Trust

  collaborator OTHER

• University of Cambridge

  lead OTHER

Principal Investigators

• Roman Hovorka, PhD · University of Cambridge

• David Dunger, MD, FRCPCH · University of Cambridge

• Peter Hindmarsh, MD, FRCPCH · University College London Hospitals

• Fiona Campbell, MD, FRCPCH · Leeds Teaching Hospitals

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

6 Years

Max Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2013-12-31

Primary Completion

2015-03-31

Completion

2015-05-31

Countries

• United Kingdom

Study Locations