Closed-loop 'artificial pancreas' insulin delivery system offers better glucose control, reduced risk of hypoglycaemia

October 3, 2018, Diabetologia

New research presented at this year's annual meeting of the European Association for the Study of Diabetes (EASD) in Berlin, Germany, and published in The Lancet, shows that use of a hybrid day-night closed-loop insulin delivery system is better than sensor-augmented pump therapy for blood sugar control in poorly controlled type 1 diabetes. The study, funded by JDRF, is by Dr. Roman Hovorka, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK, and colleagues.

Sensor-augmented pump therapy combines the technology of an with a continuous glucose monitoring sensor that transmits glucose readings to the person wearing the device. In such systems, the person wearing the device is responsible for making all insulin-dosing decisions.

Closed-loop insulin delivery systems (also known as 'artificial pancreas' systems) take the technology to the next level by integrating continuous glucose monitoring with an insulin pump and an algorithm which automates insulin delivery. Hybrid closed-loop systems are characterised by the coexistence of automated insulin delivery (via the algorithm) and user-initiated insulin delivery, for example, providing mealtime boluses. In 2017, the first hybrid closed-loop system entered clinical use based on a safety non-randomised single-arm pivotal trial.

The study randomly assigned subjects (44 male, 42 female) with type 1 diabetes aged six years and older (oldest patient 65 years) treated with insulin pump and with sub-optimal blood sugar control (glycated haemoglobin HbA1c 7·5% to 10%) to receive either hybrid closed-loop therapy (N=46; patients) or sensor-augmented pump therapy (N=40; control) over 12 weeks of unrestricted living. Training on insulin pump and continuous glucose monitoring took place over a 4-week run-in period during the study.

The proportion of time that glucose was in target range between 3·9 and 10·0mmol/l was significantly higher in the closed-loop group (65%) compared to control group (54%). In the closed-loop group, glycated haemoglobin (HbA1c —a measure of recent average blood glucose control) was reduced from a screening value of 8·3% to 8·0% post-training and 7·4% after the study. In control group these values were 8·2%, 7·8% and 7·7%; reductions in HbA1c levels were significantly greater in closed-loop group compared to control group (mean difference in change 0·36%).

The time spent with glucose levels below 3·9mmol/l (very low blood sugar or hypoglycaemia) was a median of 12 minutes was lower in the closed-loop group; and the time spent above 10·0mmol/L (hyperglycaemia) was a median of 2 hours 24 minutes lower in the closed-loop group. The proportion of time spent in these dangerous conditions overall was 3.5% median at baseline in the closed-loop group which fell to a median of 2.6% following the study. In the sensor-augmented pump group this increased from 3.3% at baseline to 3.9% after the study.

Total daily insulin dose was not different and body weight change did not differ significantly between the groups. No severe hypoglycaemia occurred, however one diabetic ketoacidosis occurred in the closed-loop due to infusion set failure.

The authors conclude: "The use of day-and-night hybrid closed-loop insulin delivery improves glycaemic control while reducing the risk of hypoglycaemia in adults, adolescents and children with type 1 diabetes compared to conventional pump therapy or sensor-augmented pump therapy. Results from our study together with those from previous studies support the adoption of closed-loop technology in clinical practice across all age groups."

"Dr. Hovorka's study is significant in that it adds to the ever-growing body of evidence showing that closed-loop delivery systems improve outcomes and reduce burden for people with type 1 diabetes," said Daniel Finan, Research Director at JDRF, who supported the study. "In particular, this study demonstrates that people with diabetes who have sub-optimal can benefit greatly from such technology."

Rachel Connor, Director of Research Partnerships at JDRF in the UK (who supported the study), said: "These are great results. I congratulate Professor Hovorka on the vital work he is doing. Type 1 diabetes is a challenging condition, but these results take us a step closer to changing the lives of the millions of people that live with the condition across the world."

Explore further: Closed-loop insulin delivery promising in T1DM pregnancy

Related Stories

Closed-loop insulin delivery promising in T1DM pregnancy

March 16, 2018
(HealthDay)—For pregnant women with type 1 diabetes, a closed-loop system is associated with comparable glucose control and significantly less hypoglycemia than sensor-augmented pump (SAP) therapy, according to a study ...

Artificial pancreas may improve overnight control of diabetes in adults

April 15, 2011
Two small randomised trials published in the British Medical Journal today suggest that closed loop insulin delivery (also known as an artificial pancreas) may improve overnight blood glucose control and reduce the risk of ...

Home use of hybrid closed-loop insulin delivery system shown safe and effective

February 13, 2017
A pivotal registration trial to evaluate in-home use of the Medtronic MiniMed 670G hybrid closed-loop insulin delivery system over 3 months showed a significant reduction in HbA1c levels for both adolescents and adults with ...

Is an insulin pump the best therapy for everyone with type 1 diabetes?

May 17, 2016
Insulin pump therapy contributes to better blood glucose control in type 1 diabetes and, as pump technology continues to improve and become part of sensor-controlled feedback and artificial pancreas systems, essentially all ...

Do closed-loop insulin delivery systems improve blood glucose control in type 1 diabetes?

August 25, 2014
In a closed-loop control approach to managing type 1 diabetes, glucose sensors placed under the skin continuously monitor blood sugar levels, triggering the release of insulin from an implantable insulin pump as needed. The ...

First-generation 'artificial pancreas' brings hope for people with type 1 diabetes

July 14, 2017
A new "artificial pancreas" being studied by the University of Melbourne could dramatically transform the lives of people with type 1 diabetes.

Recommended for you

Does diabetes damage brain health?

December 14, 2018
(HealthDay)—Diabetes has been tied to a number of complications such as kidney disease, but new research has found that older people with type 2 diabetes can also have more difficulties with thinking and memory.

Researchers study abnormal blood glucose levels of discharged patients

December 14, 2018
University of Minnesota Medical School researchers decided to delve into an area where little data currently exists. They wanted to know what happens after these patients with abnormal blood glucose measurements are discharged? ...

Researchers zero in on potential therapeutic target for diabetes, associated diseases

December 14, 2018
A recent study led by researchers in Texas A&M University's department of nutrition and food science shows how a novel regulatory mechanism serves as an important biomarker for the development of diabetes, as well as a potential ...

Researchers have found that incidence of heart failure was around two-fold higher in people with diabetes

December 11, 2018
Researchers have found that incidence of heart failure was around two-fold higher in people with diabetes.

Millions of low-risk people with diabetes may be testing their blood sugar too often

December 10, 2018
For people with Type 2 diabetes, the task of testing their blood sugar with a fingertip prick and a drop of blood on a special strip of paper becomes part of everyday life.

Very low calorie diets trialled by NHS to tackle diabetes

December 7, 2018
Hundreds of thousands of people will receive NHS help to battle obesity and type 2 diabetes under radical action set out by Simon Stevens, Chief Executive of NHS England.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.