Artificial pancreas that helps diabetics sleep safely at night
00:08 GMT, 19 June 2012
Nearly nine years after our son Louis was diagnosed with type 1 diabetes, it’s still painful to recall how it took hold of him.
It was the hot summer of 2003 and the family were on holiday on the Isle of Wight.
Temperatures had been in the 90s for a couple of weeks, so we thought little of the fact that four-year-old Louis seemed to be drinking a lot of water.
Louis Gillit, who suffers from type 1 diabetes, with his father Tim. His symptoms have included blurred vision, slurred speech, drowsiness and occasionally a loss of temper
What made us really concerned was the sudden realisation he’d lost a lot of weight — and that his energy levels were extremely low.
A normally fit, bouncy boy, he could barely summon the energy to walk the few hundred yards to the beach.
He seemed to be perpetually thirsty and also needed to urinate frequently — classic signs of diabetes, though we were totally unaware of that.
As soon as we got home to Cambridge, we took Louis to our GP, who tested his blood sugar.
Suspecting type 1 diabetes, he sent us straight to Addenbrooke’s hospital, where doctors confirmed the diagnosis.
We were terrified. We knew very little about diabetes, and the more we were told the worse we felt.
It was the start of a heartbreaking nine years desperately trying to get Louis’s condition under control — not always successfully.
Fortunately, now there is a miracle treatment that not only helps our son, but also the millions of other sufferers of type 1 diabetes.
But, first, Louis and our family had a difficult journey to go through.
While type 2 diabetes is linked to obesity, type 1 is an auto-immune condition where the pancreas stops producing insulin — the hormone that moves sugar out of the blood and into cells, where it is broken down to produce energy.
The average age of diagnosis is 14 and the incidence of the condition is surging at a rate of 4 per cent a year, but doctors don’t fully understand why.
Louis was needing to go to the loo so often because his body was trying to reduce his blood sugar levels by flushing the excess glucose out in his urine — which explained his constant thirst.
Frighteningly, we were told Louis was also developing ketones — a poisonous acid that is left over when the body is forced to burn its own fat.
This occurs when glucose remains in the blood rather than in the accessible cells — and it can be fatal. While Louis had high glucose levels, it can also affect those with low levels.
Unlike type 2 diabetics, who can control their condition with medication, type 1 diabetics need daily insulin for the rest of their life, which has to be injected or pumped into the body.
Caring for Louis would involve pricking his finger many times every day to test his blood sugar levels and performing a 24-hour balancing act to keep the levels as close to normal as possible.
‘Children with diabetes have to cope with many things that most of us barely consider,’ says Peter Hindmarsh, Professor of Paediatric Endocrinology at University College London.
The average age of diagnosis of type 1 diabetes is 14 and the incidence of the condition is surging at a rate of 4 per cent a year
‘They have to think how much insulin to take to match what they eat, as well as regular checking of blood sugar levels.’
Too much insulin (or not enough food) can lead to hypoglycaemia — ‘a hypo’ or low blood sugar.
This is remedied with sugar — glucose tablets, jelly beans or fruit juice — but if not treated, it can leave the patient in a coma.
High blood sugar levels can cause long-term complications such as heart disease or damage to the kidneys, eyes and nerves — and a reduced life expectancy.
We had to hold down Louis to administer his first few insulin injections. It was heartbreaking. But within days of being on insulin, he was gaining weight and getting back to his old self.
Two years later, his younger brother Victor, who’s now 11, was also diagnosed with type 1 diabetes — it can have a genetic link.
Louis has had hundreds of hypos over the past nine years, with his symptoms including blurred vision, slurred speech, drowsiness and occasionally a loss of temper.
He has benefited from new treatments, including an insulin pump that provides a constant, minute supply of the hormone.
The pump, which is the size of a mobile phone and worn on a belt, is attached to the skin via a tube.
Every time Louis eats, he gives himself an extra dose of insulin. He still needs to test his blood sugar levels regularly, but it is much easier to regulate them.
There is room for improvement, however, particularly at night.
Louis has to guess his overnight insulin dose before he goes to sleep, based on his current levels and how much food he has eaten.
After all Louis, now 13, has gone through, we had mixed feelings when he was asked to take part in trials at Addenbrooke’s this year.
Dr Roman Hovorka and his team are working on an ‘artificial pancreas’, which he believes will improve the lives of diabetics.
It involves continuous glucose monitoring, using a sensor worn under the skin to provide blood sugar readings, and reduce the need for so many finger-prick tests.
As it constantly adjusts insulin levels, it is aimed at reducing the risk of a night-time hypo — our worst nightmare.
The trials centred on a group of teenagers — this age group is more likely to suffer ‘irregularities’ in insulin regimens due to missed doses (they are prone to forgetfulness or stroppiness). The maths involved is complicated.
‘There are huge variables — between people and on a day-to-day basis depending on the amount of exercise they take and what type of food they are eating,’ says Dr Hovorka.
‘There are also variations in the rate of insulin absorption between patients.’
Though I was keen for Louis to take part in the trial, it was up to him.
The organisers were offering 100 to join the trial, and having decided it was an easier way to earn money than his newspaper round, Louis agreed to go ahead.
During his first 24-hour stay at the hospital, he was subjected to glucose checks every 30 minutes during the day and every 15 minutes at night (luckily, he didn’t need to be woken up).
His exercise and food intake were monitored closely — meals were timed to the minute.
For his second stay, Louis returned to the research centre to repeat the process — except that his insulin pump was controlled by Dr Hovorka’s programming rather than by the human hand.
Again, his blood sugar levels were checked, day and night.
Dr Hovorka’s mathematical wizardry certainly did the trick.
Despite the team purposely not giving Louis insulin with his dinner, the sensor soon detected higher blood sugar levels and adjusted the levels of insulin being delivered by the pump.
The next morning when we visited Louis, the team showed us his night-time readings.
Amazingly, they were a steady, safe level throughout the night.
It’s still likely to be at least five years before Dr Hovorka’s system is available, but the thought that diabetics might one day be able to rely on stable overnight blood sugar levels is exciting.
‘However, we have to bear in mind that the artificial pancreas will only be a bridge to a cure,’ says Dr Hovorka.
‘In the long term, the solution to diabetes is a biological cure, but I’m convinced we can make real improvements to diabetes care in the coming years.’
Teenager Louis was remarkably unfazed by the whole experience.
‘The trial was a bit boring because I had to just sit on my bed, and I needed to have a drip in my arm for the whole time I was there,’ he says.
‘But there was an Xbox, which passed the time.’