The world’s first clinical trial to compare three ways of delivering insulin to control glucose levels in patients with type 1 diabetes concludes that two versions of an artificial pancreas can do the job better than conventional pump therapy. The results could have significant implications for the treatment of type 1 diabetes.
The trial was conducted by researchers at the Clinical Research Institute of Montreal and the University of Montreal (IRCM), and the findings are published in The Lancet Diabetes & Endocrinology journal.
Diabetes is a disorder where the body either can’t produce or use insulin – a hormone that it needs to convert glucose from food into energy for cells. Untreated, diabetes leads to high levels of glucose in the blood, which in the long term causes serious damage to organs, including vision loss and kidney failure.
There are two main types of diabetes. Type 1 usually begins in childhood and arises when the immune system destroys insulin-producing cells in the pancreas.
Type 2 diabetes – which accounts for 95% of diabetes – results when the body fails to make use of insulin properly. The pancreas responds by making more and more insulin but eventually this is not enough and glucose levels go up.
People with type 1 diabetes require insulin; people with type 2 diabetes can take oral medication, but may also require insulin.
The purpose of the trial was to compare the effectiveness of two versions of an external artificial pancreas with conventional insulin-pump therapy in helping type 1 diabetes patients control their glucose levels.
The external artificial pancreas is an automated system designed to simulate the normal pancreas by delivering a continuous supply of insulin that adapts to changes in the patient’s glucose levels.
People with type 1 diabetes receiving insulin have to manage their blood glucose carefully, not only to stop it getting too high, but also so it does not get too low. Low glucose is a condition called hypoglycemia, which can lead to confusion, disorientation and, in extreme cases, loss of consciousness, coma and seizure.
The risk of hypoglycemia tends to get higher overnight. This can be a source of great stress and worry – not least for parents of young diabetic children.
In the body, glucose levels are kept stable by two systems: one uses insulin to reduce glucose, and the other uses glucagon to raise it.
The trial tested two configurations of the artificial pancreas: one that delivers insulin alone – the single-hormone artificial pancreas – and another that delivers insulin and glucagon – the dual-hormone artificial pancreas.
Trial leader and endocrinologist Rémi Rabasa-Lhoret, an associate professor in the Department of Nutrition at the University of Montreal, says they tested both the insulin-only and the insulin and glucagon configurations because:
“We wanted to determine the usefulness of glucagon in the artificial pancreas, especially to prevent hypoglycemia, which remains the major barrier to reaching glycemic targets.”
For the randomized crossover trial, the type 1 diabetes patients attended the clinic three times. Each visit lasted 24 hours and tested a different device. Randomized crossover means every participant used all three devices, but in a random order.
The researchers measured how well each device kept the patients’ glucose levels within minimum and maximum limits – the plasma glucose target range – over the 24-hour period. The results showed that:
“The mean proportion of time spent in the plasma glucose target range over 24 h was 62% (SD 18), 63% (18), and 51% (19) with single-hormone artificial pancreas, dual-hormone artificial pancreas, and conventional insulin pump therapy, respectively.”
The team concludes that both versions of the external artificial pancreas improved glucose control and reduced the risk of hypoglycemia compared to conventional pump therapy.
The results also showed that the dual-hormone artificial pancreas was better at reducing hypoglycemia than the single-hormone system. However, the authors note that the single-hormone system “might be sufficient for hypoglycemia-free overnight glycemic control.”
The team believes the trial shows the artificial pancreas has the potential to substantially improve the management of diabetes and the quality of life of patients and their families.
They are now planning further clinical trials to test the artificial pancreas with larger groups of patients for longer periods.
They hope the technology will be on the market in the next 5 to 7 years, with early models aimed at managing overnight glucose control.
The World Health Organization (WHO) estimates that
In October 2014, Medical News Today recently reported another treatment breakthrough for type 1 diabetes where Harvard stem cell researchers got embryonic stem cells to make billions of human insulin cells. The team also transplanted the stem cell-derived pancreatic cells into the kidney of a diabetic mouse that, after 2 weeks, showed no signs of the disease.