Bionic pancreas out performs gold-standard diabetes treatment

Two separate studies have shown that diabetics using a bionic pancreas are able to maintain their glucose levels better than with current gold-standard insulin therapy.

An artificial pancreas is a system comprising of a glucose sensor under the skin that transmits blood glucose levels to a device worn outside the body, which then uses special software to autonomously adjust the amount of insulin – the hormone that regulates blood sugar levels – administered by an insulin pump.

A study funded by Diabetes UK and carried out by researchers in Cambridge, London and Sheffield showed that a group of 24 adults with type 1 diabetes using an artificial pancreas each night for four weeks in their own homes improved the amount of time they spent overnight with blood sugar in the ideal range by 13.5 per cent.

The study was announced at the American Diabetes Association’s 74th Scientific Sessions in San Francisco yesterday, where US researchers at Boston University and Massachusetts General Hospital also released a study suggesting that bionic pancreas users were more likely to have blood glucose levels consistently within the normal range, with fewer dangerous lows or highs.

The researchers found about 37 per cent fewer interventions for hypoglycaemia – severely low blood glucose – and a more than twofold reduction in the time in hypoglycemia in adults using an artificial pancreas rather than a manual pump and monitoring kit.

For adolescents, the results showed more than a twofold reduction in the need for interventions for hypoglycaemia and both groups had significant improvements in glucose levels with the bionic pancreas, particularly during the night.

Dr Roman Hovorka was the lead author of the study at the University of Cambridge – published in The Lancet Diabetes and Endocrinology journal – which was the first in the world where adults have used such a device for more than a couple of days without medical supervision, a key test of the technologies real-world applicability.

“The advantage of a ‘closed-loop’ system like this one is the ability to fine tune insulin delivery to account for variations in overnight insulin needs,” he said.

“The system was able to adapt and safely cope with these variations to achieve more consistent glucose control. Now that we’ve tested the system at multiple centres, we can see that its benefits apply to a wide range of individuals.

“A large-scale clinical trial of the artificial pancreas will now be the next step in helping to translate these exciting findings into an end product that will help to transform the management of type 1 diabetes by achieving consistent glucose levels and reducing the risk of blood glucose levels falling dangerously low during the night. Such a product may be viable with existing technology.”

The participants switched on the device after their evening meal and turned it off again before breakfast the next morning. Every 12 minutes during the night, the software would draw on real-time feedback from the sensor to adjust the amount of insulin administered by the pump.

As well as spending longer in the ideal range, patients also had lower average overnight blood glucose levels without increasing the time they spent with their blood glucose level falling too low. The benefits even carried over into the daytime, with the system seeming to lower average glucose levels even when participants were not using it.

In the US study, published in the New England Journal of Medicine, scientists investigated two scenarios using a bi-hormonal bionic pancreas, which provides the counteracting hormone glucagon as well as insulin, via two automatic pumps.

In the first scenario, 20 adults wore the device combined with a cell phone-sized wireless monitor around Boston for five days, unrestricted in their activities. In the other, 32 youth wore the device combination for five days at a camp for children with type 1 diabetes. Both groups were also monitored for five days wearing their own conventional pumps that deliver insulin.

"The bionic pancreas system reduced the average blood glucose to levels that have been shown to dramatically reduce the risk of diabetic complications," said co-first author Dr Steven Russell, assistant professor of medicine at Massachusetts General Hospital. "This is tremendously difficult with currently available technology, and so most people with diabetes are unable to achieve these levels."

"The performance of our system in both adults and adolescents exceeded our expectations under very challenging real-world conditions," said Dr Ed Damiano, the paper's senior author, an associate professor of biomedical engineering at Boston University and the parent of a son with type 1 diabetes.

"A cure is always the end goal," he said. "As that goal remains elusive, a truly automated technology, which can consistently and relentlessly keep people healthy and safe from harm of hypoglycemia, would lift an enormous emotional and practical burden from the shoulders of people with type 1 diabetes, including my child and so many others."

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