Type 1 Diabetes
Conditions
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.
Interventions
Subcutaneous delivery of Novorapid insulin according to usual pump regime
DEVICEClosed loop
Subcutaneous delivery of Novorapid insulin, dose calculated by control algorithm, based on continuous glucose sensor readings
Sponsors
Cambridge University Hospitals NHS Foundation Trust
Diabetes UK
University of Cambridge
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
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.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Percentage of plasma glucose values in target (3.9 - 8.0 mmol/L) | 1900 to 0800hr |
Secondary
| Measure | Time frame |
|---|---|
| Percentage of plasma glucose and CGM values in target (3.9-8.0 mmol/L) | 0000 to 0800hr |
| Percentage of plasma glucose and CGM values below 3.9 mmol/L | 1900 to 0800hr |
| Percentage of plasma glucose and CGM values above 8.0 mmol/L | 1900 to 0800hr |
| Average plasma and CGM glucose | 1900 to 0800hr |
| Percentage of CGM (continuous glucose monitoring) values in target (3.9-8.0 mmol/L) | 1900 to 0800hr |
| Total dose of insulin administered | 1900 to 0800hr |
| low blood glucose index (LBGI) score | 1900 to 0800hr |
| high blood glucose index (HBGI) score | 1900 to 0800hr |
| Percentage of plasma glucose and CGM values below 3.0 mmol/L | 1900 to 0800hr |
| Average plasma insulin concentration | 1900 to 0800hr |
Countries
United Kingdom
Outcome results
None listed