CONTINUOUS GLUCOSE MONITORING (CGM)
Continuous Glucose Monitoring (CGM) provides the complete picture by revealing lows and highs that HbA1C and fingerstick testing alone cannot always identify.
The MiniMed™ 640G Insulin Pump is a sensor augmented pump (SAP) - the latest type of insulin pump that includes Continuous Glucose Monitoring (CGM) capabilities.
An insulin pump that is CGM capable means that you can see and track your glucose levels. By wearing a sensor that sends data to your pump 288 times in a 24 hour period (that’s every 5 minutes), your pump can track your glucose levels. With a Medtronic insulin pump it can even alert you to a high or low or switch off insulin delivery before your glucose levels go low!
You will need to wear a small glucose sensor that sits under the skin for up to 6 days at a time. Just like an infusion set cannula, the sensor is easily inserted using an automatic device provided with the system (known as a 'Serter'). The sensor attaches to a small lightweight transmitter* that sends glucose sensor data wirelessly to your insulin pump through advanced radio frequency (RF) wireless technology. The screen on your insulin pump displays the glucose data on screen and plots a trend line of the data so that you can see exactly what your glucose trends are and what may be affecting them.
As well as seeing the on-screen display, you can set Alerts on the insulin pump that will sound or vibrate to warn you when you are likely to reach, are reaching or have reached your glucose target limits. Having this information can help you to avoid hypo- or hyperglycaemic excursions, remain within your target glucose levels and help to reduce your HbA1C and achieve better control.
WHAT ARE THE ADVANTAGES OF CONTINUOUS GLUCOSE MONITORING (CGM)?
The advantages of CGM over traditional fingersticks and HbA1c testing are well-documented. Research has shown that:
- 60% of glucose lows may not be revealed with fingersticks alone1.
- CGM identifies four times as many serious glucose excursions as self-monitoring of blood glucose (SMBG)2.
- Several randomised controlled trials3,4,5 showed that CGM can lead to up to 1% HbA1c reduction without increasing the rate of severe hypoglycaemia and tighter glycaemic control
HOW CAN CGM BENEFIT ME?
The anecdotal and real-life stories from patients using CGM are overwhelming and include:
- Parents are able to relax and no longer feel that they have to check on their child throughout the night
- Sports enthusiasts and students who can concentrate on competing or taking their exams without worrying
- People with busy work lives who can be as busy as they like and get on with their day-to-day activities with less anxiety
- It can help women who are pregnant or thinking of having a baby to achieve the tighter control that they need for the best possible pregnancy
The National Institute for Health and Care Excellence (NICE) has assessed Continuous Glucose Monitoring and in 2015 published criteria and guidelines for its use (within NG17 & NG18).
NG17 Type 1 Diabetes in Adults: Diagnosis and Management
Consider 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.
- Hypoglycaemia (HbA1c level of 75 mmol/litremol [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.
NG18 Diabetes (Type 1 and Type 2) in Children and Young People: Diagnosis and Management
Offer 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).
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 who may be happy to lend you a transmitter and glucose sensor to trial for a few days. 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, 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, but we do offer special promotions to patients.
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’s. 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. You can view this recommendation here.
Continuous Glucose Data or ‘Flash Glucose Monitoring’ like the Abbott Freestyle Libre is different. This 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%. 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 HbA1C and help to prevent your highs and lows from happening. 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.
If you currently managing your diabetes through multiple daily injections or are wearing an insulin pump from a different manufacturer, you may benefit from understanding more about your glucose trends with Medtronic's stand alone CGM device called Guardian™ Connect. Visit the Guardian Connect website for further information.
What makes the MiniMed™ 640G insulin pump special is the power of SmartGuard™. This is completely unique to this insulin pump and is a major step forward for insulin pump technology. When SmartGuard™ is switched on, the insulin pump can actually switch off delivery of insulin to prevent you going too low and switch it back on again once sensor glucose levels are back in range – without you having to do anything. An insulin pump designed to prevent hypos - You can find out more about SmartGuard™ here.
- Pitzer KR, Desai S, Dunn T, et al. Detection of hypoglycemia with the GlucoWatch biographer. Diabetes Care. 2001;24(5):881-885.
- Kaufman FR, et al. Diabetes Care. 2001;24(12):2030-2034
- Bergenstal RM, Tamborlane WV, Ahmann A, et al. Effectiveness of sensor-augmented insulin-pump therapy in type 1 diabetes. N Engl J Med. 2010;363:311–320.)
- Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group. Continuous glucose monitoring and intensive treatment of type 1 diabetes. N Engl J Med. 2008;359(14):1464-1476.
- Raccah D, Sulmont V, Resnik Y,et al. Incremental value of continuous glucose monitoring when starting pump therapy in patients with poorly controlled type 1 diabetes: the RealTrend Study. Diabetes Care. 2009;32(12):2245-2250.
* This data is intended to supplement, not replace, blood glucose information obtained using standard home blood glucose monitoring devices. Fingersticks are required when adjusting insulin delivery and for calibrating the glucose sensor. Values are not intended to be used directly for making therapy adjustments, but rather to provide an indication of when a meter blood glucose measurement may be required. All therapy adjustments should be based on measurements obtained using a home glucose meter and not on CGM system values.
** Internal date on file; Medtronic MiniMed™, Inc
The Guardian™ 2 Link transmitter is only compatible with MiniMed™ 640G insulin pump
The MiniLink™ transmitter is compatible with MiniMed™ Paradigm Veo™ system
Guardian Connect is designed as a stand alone Continuous Glucose Monitoring System and does not integrate or link with any Medtronic insulin pump
FreeStyle, Libre and related brand marks are trademarks of Abbott Diabetes Care Inc.