A closed-loop system is a pump and a continuous glucose monitor that are able to “talk to each other”.

Sometimes, these are referred to as an “artificial pancreas”. Although they can help people manage their diabetes, people on closed-loop systems still have to carbohydrate count accurately and tell the pump when and how much insulin to inject around meals or snacks.

There are two main sorts of closed-loop systems:

The glucose sensor tells the pump when the blood glucose is going low and the pump then stops the insulin infusion until the glucose begins to rise again.

The sensor communicates all changes in blood glucose to the pump which then automatically adjusts the basal rate of insulin infusion.

Closed-loop technology is evolving very rapidly with increasing numbers of systems appearing on the market.

Who is eligible for a closed-loop system?

Availability on the NHS varies across the UK. NICE has published the outcome of their appraisal for hybrid closed-loop systems. They recommend that over the next five years, hundreds of thousands of people living with type 1 diabetes should be offered this next-generation technology to help them manage their condition.

The details of which systems will be funded and how the funding will be made available to individual areas have not yet been decided. To start with, there is likely to be more demand than areas can cope with. Therefore, the rollout to all eligible people will take time.

What are the benefits of a “closed-loop” system?

  • Improved blood sugar control
  • Reduced hypoglycaemia
  • Improved quality of life

What are the disadvantages of a “closed-loop” system?

  • Availability varies across the UK
  • Expensive if funding it yourself
  • You will need to learn a slightly different way of running the pump
  • You still need to carbohydrate count and tell the pump to do boluses
  • You need to be aware of things that will cause rapid and significant changes in blood sugar, such as exercise, as the closed-loop system will not respond quickly enough
  • You need to wear a sensor and pump all the time