In people without diabetes, pancreatic islet cells detect glucose in the blood, and release insulin or glycogen to keep the glucose level in a safe range.
All people with type 1 diabetes use a treatment ‘loop’ to mimic this function the best we can – at present this involves:
- a pump or insulin pen (for insulin delivery)
- a blood glucose monitor and maybe CGM (for glucose level assessment), and
- our brains and fingers to calculate the dose required and deliver it to complete the loop.
‘Closing the loop’ means making it happen automatically. This means a calculator or ‘algorithm’ is needed to replace our brains and fingers. The glucose assessment needs to be communicated to the algorithm, which then decides how much insulin is required and sends a message to a pump to deliver the dose. This is also called an artificial pancreas.
Research by JDRF has identified 6 key steps:
- an insulin pump with low glucose suspend when CGM detects hypoglycaemia
- predictive low glucose suspend when CGM detects glucose is falling towards hypoglycaemia
- predictive low & high glucose minimiser
- hybrid closed loop – basal rate is automated but meal-time boluses must be manually bolused
- fully automated closed loop with insulin only – needs no programming by the user
- fully automated closed loop with insulin and glucagon
Where are we now?
Step 2 is now available, with Medtronic 640G and Enlite sensors. This is known as sensor-augmented pump therapy.
(Step 5 is currently in limited in-home research trials here in the UK and around the world.)
Sensor-augmented pump therapy combines an insulin pump and a continuous glucose monitor which work together. Usually the CGM reading can be viewed on the pump’s screen.
Systems available in the UK:
- Animas Vibe + Dexcom sensors
- Medtronic Veo + Enlite sensors with low glucose suspend
- Medtronic 640G + Enlite sensors with predictive low glucose suspend
Pictures and descriptions of the Animas Vibe and Medtronic Veo can be found in the Diabetes UK Meds & Kits guide 2015 (published before the Medtronic 640G was launched).
Low glucose suspend will turn off the delivery of insulin for 2 hours if the sensor detects a hypo and the user does not respond to the alarms, for example if they are asleep.
Predictive low glucose suspend will turn off the delivery of insulin for up to 2 hours when the sensor detects that the glucose level is likely to dip into a hypo, therefore preventing the hypo from happening.
INPUT welcomes the release of NICE DG21 on integrated sensor-augmented pump therapy systems for managing blood glucose levels in type 1 diabetes (the MiniMed Paradigm Veo system and the Vibe and G4 PLATINUM CGM system)
This is NICE’s positive first guidance on the use of sensor augmented pump (SAP) therapy. INPUT believes that the appropriate use of sensor augmented pump therapy is a vital step on the path towards the eventual availability of artificial pancreas systems.
The MiniMed Paradigm Veo system is recommended as an option for managing blood glucose levels in people with type 1 diabetes only if:
– they have episodes of disabling hypoglycaemia despite optimal management with continuous subcutaneous insulin infusion and
– the company arranges to collect, analyse and publish data on the use of the MiniMed Paradigm Veo system (see section 7.1).
1.2 The MiniMed Paradigm Veo system should be used under the supervision of a trained multidisciplinary team who are experienced in continuous subcutaneous insulin infusion and continuous glucose monitoring for managing type 1 diabetes only if the person or their carer:
– agrees to use the sensors for at least 70% of the time
– understands how to use it and is physically able to use the system and
– agrees to use the system while having a structured education programme on diet and lifestyle, and counselling.
1.3 People who start to use the MiniMed Paradigm Veo system should only continue to use it if they have a decrease in the number of hypoglycaemic episodes that is sustained. Appropriate targets for such improvements should be set.
1.4 The Vibe and G4 PLATINUM CGM system shows promise but there is currently insufficient evidence to support its routine adoption in the NHS for managing blood glucose levels in people with type 1 diabetes. Robust evidence is needed to show the clinical effectiveness of using the technology in practice.
1.5 People with type 1 diabetes who are currently provided with the MiniMed Paradigm Veo system or the Vibe and G4 PLATINUM CGM system by the NHS for clinical indications that are not recommended in this NICE guidance should be able to continue using them until they and their NHS clinician consider it
appropriate to stop.
Note that DG21 applies to:
- MiniMed Paradigm Veo System, used with Medtronic Enlite CGM sensors
- Animas Vibe, used with Dexcom G4 PLATINUM CGM sensors
Please see this INPUT news item for comments and clarification of some points of confusion following the release of this guidance.
NICE were keen to point out that this guidance does not cover Medtronic 640G, but they have written this descriptive document about it:
NICE Medtech Innovation Briefings (MIBs) are designed to support NHS and social care commissioners and staff who are considering using new medical devices and other medical or diagnostic technologies.
The information provided includes a description of the technology, how it’s used and its potential role in the treatment pathway.
A MIB also includes a review of relevant published evidence and the likely costs of using the technologies. They are designed to be fast, flexible and responsive to the need for information on innovative technologies.
Also in development
23 June 2015 Insulin Nation article about Bigfoot Biomedical
Imperial College Hospital b.iap (bio inspired artificial pancreas)
Addenbrooke’s Hospital, Cambridge (Dr Roman Hovorka)