Cambridge scientists have successfully tested an artificial pancreas for patients with type 2 diabetes. The device – powered by an algorithm developed at the University of Cambridge – doubled the amount of time patients were in range target for glucose compared to standard treatment and cut the time spent feeling elevated glucose levels in half.
It is estimated that approximately 415 million people worldwide live with type 2 diabetes, costing approximately $760 billion in annual global healthcare expenditure. According to Diabetes UK, in the UK alone, more than 4.9 million people have diabetes, 90% of them with type 2 diabetes, costing the NHS £10 billion a year.
Type 2 diabetes causes glucose (blood sugar) levels to get too high. Usually, blood sugar is controlled by the release of insulin, but in type 2 diabetes, insulin production is disrupted. Over time, this can cause serious problems, including eye, kidney and nerve damage and heart disease.
The disease is usually managed by a combination of lifestyle changes – improved diet and more exercise, for example – and medication, in an effort to keep glucose levels low.
Researchers at the University of Cambridge’s Wellcome-MRC Institute of Metabolic Science have developed an artificial pancreas that can help maintain healthy glucose levels. The device combines a plug-and-play glucose monitor and insulin pump with a team-developed app known as CamAPS HX. This app is driven by an algorithm that predicts the amount of insulin needed to keep glucose levels within the target range.
Researchers have previously shown that an artificial pancreas run by a similar algorithm is effective for patients with type 1 diabetes, from adults to very young children. They also successfully tested the device in patients with type 2 diabetes requiring kidney dialysis.
Today in natural medicine, the team reports the first trial of the device in a wider population living with type 2 diabetes (not requiring kidney dialysis). Unlike the artificial pancreas used for type 1 diabetes, this new version is a fully closed-loop system — where patients with type 1 diabetes must tell their artificial pancreas that they are regarding to eat to allow insulin adjustment, for example, with this version they can let the device work fully automatically.
The researchers recruited 26 patients from the Wolfson Diabetes and Endocrine Clinic at Addenbrooke’s Hospital, part of Cambridge University Hospitals NHS Foundation Trust, and a local group of medical practices. Patients were randomly assigned to one of two groups – the first group would test the artificial pancreas for eight weeks, then switch to the standard treatment of multiple daily insulin injections; the second group would first follow this control therapy and then switch to the artificial pancreas following eight weeks.
The team used several measures to assess the effectiveness of the artificial pancreas. The first was the proportion of time patients spent with their blood sugar levels within a target range of 3.9 to 10.0 mmol/L. On average, patients using the artificial pancreas spent two-thirds (66%) of their time in the target range – double that during the control (32%).
A second measure was the proportion of time spent with glucose levels above 10.0 mmol/L. Over time, high glucose levels increase the risk of potentially serious complications. Patients taking the controller treatment spent two-thirds (67%) of their time with elevated glucose levels – this figure was halved to 33% when using the artificial pancreas.
Average glucose levels fell – from 12.6 mmol/L when taking the control treatment to 9.2 mmol/L when using the artificial pancreas.
The app also reduced levels of a molecule known as glycated hemoglobin or HbA1c. Glycated hemoglobin develops when hemoglobin, a protein in red blood cells that carries oxygen throughout the body, joins with glucose in the blood, becoming “glycated”. By measuring HbA1c, clinicians are able to get an overall picture of a person’s average blood sugar over a period of weeks or months. For people with diabetes, the higher the HbA1c, the higher the risk of developing diabetes-related complications. After the control therapy, the average HbA1c levels were 8.7%, whereas following the use of the artificial pancreas they were 7.3%.
No patient experienced dangerously low blood sugar levels (hypoglycaemia) during the study. A patient was hospitalized while using the artificial pancreas, due to an abscess at the cannula of the pump.
Dr Charlotte Boughton from the University of Cambridge’s Wellcome-MRC Institute of Metabolic Science, who co-led the study, said: “Many people with type 2 diabetes find it difficult to manage their blood sugar using currently available treatments, such as insulin. The artificial pancreas can provide a safe and effective approach to helping them, and the technology is simple to use and can be implemented safely at home.
Dr Aideen Daly, also from the Wellcome-MRC Institute of Metabolic Science, said: “One of the barriers to the widespread use of insulin therapy has been concern over the risk of severe ‘hypos’ – dangerously low blood sugar levels. But we found that none of the patients in our trial experienced this and the patients spent very little time with blood sugar levels below target levels.”
Participant feedback suggested participants were happy that their blood sugar was automatically controlled by the system, and nine in ten (89%) said they spent less time managing their diabetes overall. Users highlighted the elimination of the need for injections or finger prick tests, and increased confidence in blood sugar management as key benefits. Disadvantages included increased anxiety regarding the risk of hypoglycemia, which researchers believe may reflect increased awareness and monitoring of glucose levels, and practical inconveniences associated with wearing devices.
The team now plans to conduct a much larger multicenter study to build on their findings and has submitted the device for regulatory approval with a view to making it commercially available for outpatients with type 2 diabetes.
The research was supported by the Cambridge Biomedical Research Center of the National Institute for Health and Care Research (NIHR).
