Continuous Glucose
Monitoring (CGM)


Some people use CGM simply to visualise their glucose patterns and see what their glucose is doing. But the real power is in setting alerts on the reader/insulin pump so that you can be warned of, or before, a high or low glucose level. You can use it to help you manage highs and lows more quickly, and also try to avoid them. Using CGM has been shown to help patients manage their diabetes even more than just using a pump on its own3.

Medtronic has been integrating CGM into their insulin pumps for some time now to minimise the equipment that patients need to wear to help them to manage their diabetes even more effectively.1 SmartGuard®, which is Medtronic’s latest CGM technology, goes a step further than any other CGM. It actually allows the insulin pump to use the CGM readings and switch insulin off and turn it back on again when it predicts that you are going to have a lower sugar level than you would like.

SmartGuard® is unique to Medtronic and only available on the MiniMed™ 640G System. It is revolutionising Type 1 Insulin pump therapy and it is why thousands of patients have chosen to use the MiniMed™ 640G.


How SmartGuard® Works

*The dynamic suspend feature is based on certain criteria: sensor glucose must be within 3.9mmol/L of the low limit and predicted to be 1.1mmol/L above the low limit within 30 minutes AND the pump must not be in the refractory period. **The dynamic resume feature is based on certain preset criteria: sensor glucose must be 1.1mmol/L above the preset low limit and predicted ot be 2.2mmol/L above within 30 minutes AND insulin must have been suspended for at least 30 minutes.

Smartguard Graph

Enlite Glucose Sensor

Is CGM the same as ‘Flash Glucose Monitoring’?

Continuous Glucose Data or ‘Flash Glucose Monitoring’ like the Abbott Freestyle Libre are different. Flash glucose monitoring involves using a glucose sensor and a reader, but it doesn’t allow you to set alerts or control any of your insulin delivery and is also not calibrated for accuracy while you are wearing it. Medtronic glucose sensor accuracy is an impressive MARD 9.1%4. For some people the Freestyle Libre is useful, but it doesn’t offer the same day to day benefits or protection from hypoglycaemia.

The real difference is that you have alerts that you can set with CGM that you can’t with flash-type monitors. With CGM you can actually be warned if your glucose is going high or low – and this is what can actually help to improve your HbA1C5 and help to prevent your highs and lows from happening6. For most people this is the reason that they want to use some sort of glucose monitoring in the first place. Most people want their system to be more than just something extra to wear, and really becoming technology which can take some of the hard work and burden away from you.

How much does CGM Cost?

Medtronic’s CGM is integrated into all of its insulin pumps so the features are already there for you to use. You just need a glucose sensor and transmitter to start using them. The NHS fund these for a lot of people, but some also buy them themselves. CGM is extremely popular these days. Just as you do for an insulin pump, you need to fit certain criteria for the NHS to fund your sensors. You can read more about this for Adults and Children here, and you should discuss your suitability for CGM with your healthcare professional. If you want to buy them yourself then we do sometimes offer special promotions. Please note that the funding guidelines around CGM have changed relatively recently and many hospital teams are still organising their funding streams so this is something to discuss with them.

What does the NHS say?  the National Institute for Health and Care Excellence (NICE) is the independent body that assesses the technologies, drugs and equipment used within the NHS for its clinical and cost-effectiveness. They make recommendations for example about which technologies will deliver effective treatment for particular patients at a cost that the NHS can afford.

NICE published Guidance on CGM funding in 2015 (NG17 and NG18) and Guidance on specific technologies later in 2016 (DG21) which specifically assessed the most modern types of insulin pumps – Sensor Augmented Insulin Pumps. These are insulin pumps with built in CGM capabilities. As an independent body, NICE takes a fair and impartial view on technology and its benefits looking at clinical trials and hard data, not the manufacturing company’s claims. So although other insulin pumps using CGM exist, none of these are recommended. Under NICE DG21 anyone being funded by the NHS for a sensor augmented insulin pump should be offered the Medtronic system.

CGM on the NHS

Am I eligible for Continuous Glucose Monitoring (CGM) Funding under the NHS?

The National Institute for Health and Care Excellence (NICE) has also assessed Continuous Glucose Monitoring and in 2015 published criteria and guidelines for its use (within NG17 & NG18). This document is not a Technology Appraisal but a Nice Guideline and is not so black and white.

NG17 Type1 Diabetes in Adults: Diagnosis and ManagementConsider real-time continuous glucose monitoring for adults with type 1 diabetes who are willing to commit to using it at least 70% of the time and to calibrate it as needed, and who have any of the following despite optimised use of insulin therapy and conventional blood glucose monitoring:

  • More than 1 episode a year of severe hypoglycaemia with no obviously preventable precipitating cause.
  • Complete loss of awareness of hypoglycaemia.
  • Frequent (more than 2 episodes a week) asymptomatic hypoglycaemia that is causing problems with daily activities.
  • Extreme fear of hypoglycaemia.
  • Hyperglycaemia (HbA1c level of 75 mmol/mol [9%] or higher) that persists despite testing at least 10 times a day (see recommendations 47 and 48). Continue real-time continuous glucose monitoring only if HbA1c can be sustained at or below 53 mmol/mol (7%) and/or there has been a fall in HbA1c of 27 mmol/mol (2.5%) or more. 
CGM on the NHS
CGM on the NHS

NG18 Diabetes (Type 1 and Type 2) in Children and Young People: Diagnosis and ManagementOffer ongoing real-time continuous glucose monitoring with alarms to children and young people with type 1 diabetes who have:

  • frequent severe hypoglycaemia or
  • impaired awareness of hypoglycaemia associated with adverse consequences (for example, seizures or anxiety) or
  • inability to recognise, or communicate about, symptoms of hypoglycaemia (for example, because of cognitive or neurological disabilities). 

Again you should discuss these criteria and your own personal situation with your Healthcare Professional to see whether CGM is a suitable treatment option for you to use. Most hospital teams have CGM systems now so you should talk to your Healthcare Professional.

Click here to find out more about Continuous Glucose Monitoring and what is involved

It is worth mentioning that many Hospital teams are still in the process of agreeing their CGM funding policy but it is still worth discussing your funding situation. Likewise, even if you have discussed it on a previous occasion, this guidance is relatively new and may mean that your eligibility could have changed.

You may also buy your own glucose sensors. Costs for this vary depending on how frequently you use the system.

Which System will the NHS Fund?

NICE published some additional Guidance in 2016 (DG21), specifically assessing the most modern types of insulin pumps – Sensor Augmented Insulin Pumps. These are insulin pumps with built in CGM capabilities. Assessing clinical efficacy and cost effectiveness they have only recommended one manufacturer’s insulin pump – Medtronic’sv.

As an independent body, NICE takes a fair and impartial view on technology and its benefits looking at clinical trials and hard data, not the manufacturing company’s claims. So although other insulin pumps using CGM exist, none of these are recommended.