Closing the Loop for 36 Hours in Adolescents With Type 1 Diabetes

2014-08-27 03:15:41 | BioPortfolio


High variability of blood sugar levels and high incidence of night-time hypoglycaemia (low blood sugar) in young people with type 1 diabetes (T1D) make achieving the treatment goals in this population extremely challenging.

Our ongoing research focuses on the development of a closed-loop glucose control in children and adolescents with T1D. The three components of the closed-loop system are a continuous glucose monitor, an insulin pump, and a computer-based algorithm. The studies performed thus far evaluated the efficacy and safety of overnight closed-loop glucose control. The results showed that overnight closed-loop improved control of blood glucose and prevented nocturnal hypoglycaemia, as compared to the conventional insulin pump therapy. The next objective is to evaluate the efficacy and safety of closed-loop insulin delivery over a prolonged time period, including the daytime, when normal living activities occur. This will pave the way for a more comprehensive use of closed loop systems to control glucose levels in T1D.

The present study adopts an open-label, randomised, 2-period cross-over design whereby the safety and efficacy of closed-loop insulin therapy will be compared with the conventional insulin pump therapy in 12 adolescents with T1D. Participants aged 12 to 18 years will be randomised for two 36 hour studies in a clinical research facility, during which glucose levels will be controlled by either the computer-based closed-loop algorithm (intervention arm) or by conventional insulin pump therapy (control arm). During both studies participants will perform normal daily activities, i.e. playing, reading, snacking and physical activity. On both occasions, the Actiheart, a combined heart rate and movement sensor will be used to accurately quantify each subject's individual physical activity energy expenditure during the 36 hour study period and for 36 hours of free living during weekday.


The study is an open-label, randomised, 2-period crossover study comparing the closed-loop insulin therapy with the conventional insulin pump therapy in 12 adolescents with type 1 diabetes.

Subjects who consented to take part in the study will attend the Clinical Research Facility on two occasions, each lasting 36 hours. Approximately 1-3 days prior to each Study Visit, a subcutaneous continuous glucose monitoring (CGM) device will be inserted.

On each Study Visit subjects will arrive between 17:30 and 18:00 and will stay in the clinical research facility for two nights.

Shortly after arrival the subjects will have Actiheart monitor fitted and a cannula inserted into a vein of one arm for blood sampling purposes. Blood sampling for plasma glucose and plasma insulin will start at 18:30 and will be carried out at 30 minutes intervals during the day and at 60min intervals during the night throughout the study period. Plasma glucose measurements will be done in real time every 30min during the day and every 60min during the night except when when plasma glucose < 3.5mmol/L or following treatment for hypoglycaemia, when the measurements will be carried out every 15 minutes.

On Study Visit 1 the subjects will be randomised on arrival to receive either the conventional insulin pump therapy or the closed-loop intervention. At 18:30 subjects will perform 5 to 10 minutes exercise on a bicycle to determine the settings needed to achieve a heart rate of 140 bpm corresponding to an exercise level at 55%60% of peak VO2. In the closed-loop intervention arm the insulin pump therapy will be driven by the computer-based algorithm from 19:30 until the end of the study. The basal insulin infusion rate on the insulin pump will be adjusted manually at 15min intervals following the computer-based algorithm advice. During the control arm, the subject will carry on with their usual insulin pump regimen. In both groups CGM will be continued throughout the whole of the study period. Subjects who completed Study Visit 1 will cross over to the alternative Study Visit schedule after an interval of 1 to 6 weeks.

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Crossover Assignment, Masking: Open Label, Primary Purpose: Treatment


Type 1 Diabetes


Closed-loop insulin delivery, Standard insulin pump treatment


Wellcome Trust Clinical Research Facility, Addenbrooke's Hospital
United Kingdom


Not yet recruiting


University of Cambridge

Results (where available)

View Results


Published on BioPortfolio: 2014-08-27T03:15:41-0400

Clinical Trials [3694 Associated Clinical Trials listed on BioPortfolio]

Effect of Basal-Bolus Closed-Loop Co-Administration of Insulin and Pramlintide on Improving the Glycemic Control in Type 1 Diabetes

The closed-loop delivery system is composed of an insulin pump, a continuous glucose sensor and a dosing algorithm that calculates the insulin dose to infuse based on sensor readings. Pram...

Closed Loop Insulin Pump Therapy After Islet Auto-Transplantation

The purpose of this study is to determine the effectiveness of closed loop insulin pump therapy to control blood sugar following total pancreatectomy and islet auto-transplantation (TPIAT)...

Closed-loop Control of Glucose Levels (Artificial Pancreas) for 2 Weeks in Adults With Type 1 Diabetes

Closed-loop strategy is composed of three components: glucose sensor to read glucose levels, insulin pump to infuse insulin and a dosing mathematical algorithm to decide on the required in...

Closed-loop Control of Glucose Levels (Artificial Pancreas) for 2 Weeks in Adolescents and Adults With Type 1 Diabetes

Closed-loop strategy is composed of three components: glucose sensor to read glucose levels, insulin pump to infuse insulin and a dosing mathematical algorithm to decide on the required in...

Assessment of an Automatic Closed-loop Insulin Delivery System

The overall aim of this research proposal is to determine the safety, feasibility and efficacy of an automatic closed-loop insulin delivery system.

PubMed Articles [26303 Associated PubMed Articles listed on BioPortfolio]

Keeping Up with the Diabetes Technology: 2016 Endocrine Society Guidelines of Insulin Pump Therapy and Continuous Glucose Monitor Management of Diabetes.

Decades after the invention of insulin pump, diabetes management has encountered a technology revolution with the introduction of continuous glucose monitoring, sensor-augmented insulin pump therapy a...

A randomized controlled trial-based algorithm for insulin-pump therapy in hyperglycemic patients early after kidney transplantation.

Treating hyperglycemia in previously non-diabetic individuals with exogenous insulin immediately after kidney transplantation reduced the odds of developing Posttransplantation Diabetes Mellitus (PTDM...

Ultrafast glucose-responsive, high loading capacity erythrocyte to self-regulate the release of insulin.

Insulin (INS) delivery system that can mimic normal insulin secretion to maintain the blood glucose level (BGL) in the normal range is an ideal treatment for diabetes. However, most of the existing cl...

Synthetic "smart gel" provides glucose-responsive insulin delivery in diabetic mice.

Although previous studies have attempted to create "electronics-free" insulin delivery systems using glucose oxidase and sugar-binding lectins as a glucose-sensing mechanism, no successful clinical tr...

Serum insulin bioassay reflects insulin sensitivity and requirements in type 1 diabetes.

Insulin resistance could increase insulin requirements in type 1 diabetes (TD1). Current insulin immunoassays do not detect insulin analogues. Kinase Insulin Receptor Activation (KIRA) bioassays speci...

Medical and Biotech [MESH] Definitions

Portable or implantable devices for infusion of insulin. Includes open-loop systems which may be patient-operated or controlled by a pre-set program and are designed for constant delivery of small quantities of insulin, increased during food ingestion, and closed-loop systems which deliver quantities of insulin automatically based on an electronic glucose sensor.

A syndrome with excessively high INSULIN levels in the BLOOD. It may cause HYPOGLYCEMIA. Etiology of hyperinsulinism varies, including hypersecretion of a beta cell tumor (INSULINOMA); autoantibodies against insulin (INSULIN ANTIBODIES); defective insulin receptor (INSULIN RESISTANCE); or overuse of exogenous insulin or HYPOGLYCEMIC AGENTS.

Diminished effectiveness of INSULIN in lowering blood sugar levels: requiring the use of 200 units or more of insulin per day to prevent HYPERGLYCEMIA or KETOSIS. It can be caused by the presence of INSULIN ANTIBODIES or the abnormalities in insulin receptors (RECEPTOR, INSULIN) on target cell surfaces. It is often associated with OBESITY; DIABETIC KETOACIDOSIS; INFECTION; and certain rare conditions. (from Stedman, 25th ed)

An insulin preparation that is designed to provide immediate and long term glycemic control in a single dosage. Biphasic insulin typically contains a mixture of REGULAR INSULIN or SHORT-ACTING INSULIN combined with a LONG-ACTING INSULIN.

Insulin formulation containing substance which delays or retards time period of the absorption of insulin.

More From BioPortfolio on "Closing the Loop for 36 Hours in Adolescents With Type 1 Diabetes"

Quick Search


Relevant Topics

Within medicine, nutrition (the study of food and the effect of its components on the body) has many different roles. Appropriate nutrition can help prevent certain diseases, or treat others. In critically ill patients, artificial feeding by tubes need t...

Diabetes is a lifelong condition that causes a person's blood sugar level to become too high. The two main types of diabetes are: type 1 diabetes type 2 diabetes In the UK, diabetes affects approximately 2.9 million people. There are a...

Pediatrics is the general medicine of childhood. Because of the developmental processes (psychological and physical) of childhood, the involvement of parents, and the social management of conditions at home and at school, pediatrics is a specialty. With ...

Searches Linking to this Trial