Type 1 diabetes - caused by the immune system turning inward and attacking the healthy pancreas - affects about 400,000 people in the UK. Type 2 diabetes, where not enough insulin is produced to meet demand, affects more than three million people. Risk factors include being overweight and age.
All sufferers of type 1 diabetes, and some with more advanced type 2, take synthetic insulin. The hormone has to get directly into the bloodstream and it is traditionally given as injections. The downside is that patients need to judge how much insulin to self-administer depending on what they have eaten and how active they have been.
If they inject too little, high glucose levels occur, which can lead to long-term complications. Too much leaves the patient at risk of hypoglycaemia - or a 'hypo' - where there is too little blood sugar. This can result in loss of consciousness and convulsions.
Insulin pump therapy is designed to mimic the way in which the pancreas works, providing a constant supply of insulin that can be adjusted according to individual need, compensating for daily activity and food intake and so avoiding the highs associated with meals or the lows from too much insulin. The new pump developed by Welsh company Cellnovo, and approved by the National Institute for Health and Care Excellence (NICE) for the NHS, is about the size of a box of matches. It is attached to the skin with an adhesive patch and secured to a small tube inserted into the body through which insulin is delivered. The battery-powered pump uses a 'wax engine' to propel precise amounts of insulin by using heat to create movement.
Inside the device is a tiny piece of wax. When the device decides insulin is needed, it warms the metal reservoir containing the wax. The wax melts and expands by up to 20 per cent of its solid volume.
As it expands, it pushes on a metal plate, which in turn puts pressure on a piston that drives insulin out and into the cannula, and into the blood stream. After use, the wax solidifies and shrinks, taking the pressure off the piston. The wearer just tops up the reservoir with insulin when requested by the unit.
The technology allows a far greater degree of accuracy than other pumps, which apply mechanical pressure to deliver insulin.
'It's very good news,' says Dr Peter Hammond, consultant in diabetes at Harrogate Hospital.
Chris Lowe, 46, who runs a gardening business in Bishop Thornton, North Yorkshire, is one of the first people to use the device. He says it has cut the number of hypos he suffers from three or more a day to fewer than three a week.
He says: 'It has changed my life. It fits under a shirt and I can wear it while I am working and in the shower. But the really fantastic thing is that it monitors and controls blood glucose just like a healthy pancreas.'
- Daily Mail
