Diabetes and technology meet
Researchers are devising an artificial pancreas that could cut complications for diabetes patients, writes Lynnette Hoffman
FOR 10 months running, Karen Rose woke up hourly through the night to check her son Brendan’s blood sugar levels ‘‘ to ensure he stayed alive’’. Brendan, who suffers from type 1 diabetes, had developed a complication that caused his blood sugar to spike and dip unpredictably several times a day, straining his organs and putting him at greater risk of seizures, unconsciousness and even death in the short term.
In the longer term, he faced complications including heart disease and stroke.
Trying to maintain a stable blood glucose level to minimise those risks is no simple task, as Rose can tell you.
But international researchers are edging closer to technology that could make the battle significantly easier — dramatically cutting down complications such as those above, as well as blindness, renal failure and amputations for patients with type 1 and insulin-dependent type 2 diabetes.
Some 250,000 Australians are affected, and the number is growing. The number of children with type 1 diabetes is increasing at a rate of about 5 per cent a year, according to a report by Australian Institute of Health and Welfare last year. The report also found that death rates for people with insulin-treated diabetes were three times higher than in the general population. The disease shaves an average 15 years off lifespans.
To combat all that, researchers from the Juvenile Diabetes Research Foundation are working to create an ‘‘ artificial pancreas’’. They are using complicated mathematical equations to develop software that links existing technologies — insulin pumps and continuous glucose monitors — so they work like a real pancreas, says Aaron Kowalski, director of JDRF’s international artificial pancreas program.
Everything from hormones to stress levels and from diet to exercise has an impact on glucose levels, so getting the right amount of insulin at the right time is a constant challenge. ‘‘ Fewer than 50 per cent of people with type 1 diabetes achieve target glucose levels,’’ Kowalski says. ‘‘ Even with advanced tools it’s very difficult to get their glucose levels close to (those of) a person who doesn’t have diabetes. Even people monitoring nine times a day spend less than 30 per cent of the day in the target range.’’
The JDRF researchers are developing algorithms that predict changes caused by human behaviour, so that the insulin goes directly where it’s needed in real time.
The way current technology works, there’s a time lag between sensing glucose levels in the blood and actually getting the insulin to where it needs to be.
The longer the delays, the more the complications, says associate professor Fergus Cameron, head of diabetes services at the Royal Children’s Hospital in Melbourne. ‘‘ Glucose changes are happening in a very deep part of the body where the pancreas and the liver are, whereas we’re sensing it in the skin and delivering it in the periphery, miles away from where it’s actually happening,’’ he says.
When glucose levels change in the blood it might take 10 minutes before there is a similar change in the tissue of the skin, and likewise it can take about half an hour for insulin delivered to the skin to actually change glucose levels in the blood.
Previous attempts to improve the system have included inserting glucose sensors close to the heart, but that kind of invasive procedure has complications of its own, leading to renewed focus on a high-tech solution, Cameron says.
Other current research is looking at transplanting the islet cells in the pancreas that create insulin.
Type 1 diabetes is caused by the body’s inability to make insulin, or make enough, because these cells have been destroyed. In type 2 diabetes, insulin is there but cells lose their ability to metabolise glucose in response to the hormone.
Cameron says a technological solution will probably happen before a biological one.
Small-scale studies have already shown that preliminary versions of the artificial pancreas work in controlled hospital settings. But more work needs to be done before it will be available for use in real people in everyday life.
Scientists are still learning what factors impact glucose levels, and in what ways — and that information is essential to developing the algorithms that make the software work, says associate professor Tim Jones, a paediatric diabetes specialist at Princess Margaret Hospital, who is researching exactly that.
‘‘ For example, when you’re asleep your body doesn’t protect blood glucose as well as when you’re awake, so your levels might go lower,’’ Jones says. ‘‘ Or when you exercise during the day, it takes your body 18 hours to replace the energy to the muscles, so your blood glucose would drop overnight and that can result in a seizure,’’ he says.
Different forms of exercise also have different effects. A steady jog lowers blood glucose much more quickly than the sort of stop-start exercise that kids tend to play, while a hard sprint actually makes it go up. THE federal Government announced this month that it will fund subsidies to help people living with insulin-dependent diabetes access insulin pumps. While are still imperfect, they do achieve better results than simply injecting insulin.
Currently fewer than 17 per cent of people with type 1 diabetes who are under age 18 use the pumps, which range in price from $6000 to $8000. The most recent budget allocated $5.5 million over four years to help make them more affordable.
Families with incomes of less than $59,842 will be eligible for the maximum subsidy of $2,500, while those earning between $59,842 and $98,386 will be eligible for a sliding scale of subsidy ranging from $500 to $2,500. A $500 subsidy will be available for families with incomes above that.
‘‘ With research clearly showing the longterm health benefits of good blood glucose control, it makes good economic sense for the Government to subsidise this technology for people that really need it,’’ says Diabetes Australia CEO Matt O’Brien.
On guard: Fergus Cameron with young patient Mitchell, 13. Technology has been harnessed to replace the need for needles.