Artificial pancreas hope for children with diabetes

Scientists in Cambridge have shown that an "artificial pancreas" can be used to regulate blood sugar in children with Type 1 diabetes.

A trial found that combining a "real time" sensor measuring glucose levels with a pump that delivers insulin can boost overnight blood sugar control.

The Lancet study showed the device significantly cut the risk of blood sugar levels dropping dangerously low.

Experts said the results were an important "step forward".

Type 1 diabetes is a chronic, life threatening condition, in which the pancreas does not produce insulin - the hormone that regulates blood sugar levels.

In total, 17 children and teenagers with Type 1 diabetes took part in the study over 54 nights in hospital.

Individually, the glucose monitoring system and the insulin pump used in the study are both already widely used and commercially available.

But in order to turn them into a "closed loop" system which monitors the patient's condition and delivers treatment accordingly, the researchers developed a sophisticated algorithm to calculate the appropriate amount of insulin to deliver based on the real-time glucose readings.

They then measured how well the artificial pancreas system controlled glucose levels compared with the children's regular continuous pump, which delivers insulin at preselected rates.

Low blood sugar

Testing was done in different circumstances - for example on nights when the children went to bed after eating a large evening meal, which can lead to 'insulin stacking' or having done early evening exercise - both of which can increase the risk of low blood sugar episodes known as hypoglycaemic attacks or "hypos".

1 - Continuous glucose sensor monitors blood sugar level 2 - Data transmitted for the computer programme to work out insulin dose 3 - Insulin pump delivers the dose

Overall, the results showed the artificial pancreas kept blood glucose levels in the normal range for 60% of the time, compared with 40% for the continuous pump.

And the artificial pancreas halved the time that blood glucose levels fell below 3.9mmol/l - the level considered as mild hypoglycaemia.

It also prevented blood glucose falling below 3.0mmol/l, which is defined as significant hypoglycaemia, compared with nine hypoglycaemia events in the control groups.

Study leader Dr Roman Hovorka said: "This is the first randomised study showing the potential benefit of the artificial pancreas system overnight using commercially-available sensors and pumps.

"Our study provides a stepping stone for testing the system at home."

Karen Addington, chief executive of Juvenile Diabetes Research Foundation, who funded the research said the study provided "proof of principle" of an artificial pancreas.

"We need to redouble our efforts to move the artificial pancreas from a concept in the clinic to a reality in the home of children and adults with type 1 diabetes."

Dr Victoria King, research manager at leading health charity Diabetes UK, said: "This is an important step forward in managing overnight blood glucose levels as well as in the eventual development of a full 'artificial pancreas' which could vastly improve the quality of life for people with type 1 diabetes and reduce the risk of the associated complications."

Diabetes sugar 'can go too low'

Intense treatment to lower blood sugar in patients with diabetes could prove nearly as harmful as allowing glucose levels to remain high, a study says.

Cardiff researchers looked at nearly 50,000 patients with type 2 diabetes and found the lowest glucose levels linked to a heightened risk of death.

Significant differences in death rates between patients on insulin and those taking tablets are also flagged up.

But there could be various explanations for this, experts noted.

Patients taking insulin-based treatments have been urged not to stop taking their medication as a result of the Cardiff University study, which is published in The Lancet.

Changing treatments

Using data from GPs, the team identified 27,965 patients with type 2 diabetes whose treatment had been intensified to include two oral blood glucose lowering agents - metformin and sulphonylurea.

A further 20,005 patients who had been moved on to treatment which included insulin were added to the study.

Patients whose HbA1c levels - the proportion of red blood cells with glucose attached to them - were around 7.5%, ran the lowest risk of dying from any cause.

For both groups this risk went up by more than half if levels dropped to 6.4%, the lowest levels recorded. For those with the highest levels the risk of death increased by nearly 80%.

But the risks appeared to be particularly pronounced among those on the insulin-based regimen than those on the combined treatment.

Irrespective of whether their HbA1c levels were low or high, there were 2,834 deaths in the insulin-taking group between 1986 and 2008, nearly 50% more than in the combined group.

'Don't stop'

The authors acknowledged there could be various factors associated with this, such as these being older patients with more health problems, who perhaps had had diabetes for a longer period of time. They also make reference to a possible link between use of insulin and cancer progression that had been reported in a different study.

"Whether intensification of glucose control with insulin therapy alone further heightens risk of death in patients with diabetes needs further investigation and assessment of the overall risk balance," wrote lead author Dr Craig Currie.

"Low and high mean HbA1c values were associated with increased all-cause mortality and cardiac events. If confirmed, diabetes guidelines might need revision to include a minimum HbA1c value."

Dr Iain Frame, head of research at Diabetes UK, described the study as "potentially important" but stressed it had limitations.

"It is not clear what the causes of death were from the results reported. Furthermore, when it comes to the suggestion made in this research that insulin could increase the risk of death, we must consider important factors such as age, the duration of their diabetes and how the participants managed their condition.

"It is crucial to remember that blood glucose targets should always be agreed by the person with diabetes and their healthcare team according to individual needs and not according to a blanket set of rules."

While people would be able to manage their condition for a period with diet, exercise and even tablets, many would eventually have to move on to insulin, he noted.

"We would advise people with type 2 diabetes who use insulin not to stop taking their medication. However, if they are worried about blood glucose targets, they should discuss this with their healthcare team."