5 Myths about CGM
March 1, 2017
by Bonnie Goldberg, MA, RD, CDE
Bonnie is a Registered Dietitian with a Masters Degree in Health Education from Columbia University. She specializes in diabetes care and has spent her career educating and empowering people with diabetes. She is proud to currently work for Medtronic.
When first thinking about insulin pump therapy or continuous glucose monitoring (CGM), did you have questions or thoughts of what it might be like and how it would work? Maybe you were concerned about what taking the next step would be like? Or, you may have used CGM in the past, but with so many advancements over the last couple of years there may be other things you could learn. Today, we address a few misconceptions or myths people associate with CGM, and tell you the real answers.
Myth 1: If I go on CGM, it will replace my fingerstick tests.
Reality: While this is the goal for the therapy in the future, today’s CGM devices do not completely replace fingerstick testing. Since sensor readings are taken from your interstitial fluid and not your blood, you still need to test using a BG meter. This is required to calibrate the sensor throughout the day, to make sure the glucose sensor maintains accuracy over time and always when deciding whether or not to make a treatment decision.
Myth 2: CGM devices are not accurate.
Reality: An oldie but goodie. It is important to note that sensor glucose readings are taken from your interstitial fluid (fluid surrounding the cells in your tissue), whereas fingerstick tests are taken directly from your blood. Because the readings are from two different places, there is a natural lag between glucose levels in the interstitial fluid and glucose levels in the blood. Therefore, it’s normal, and should be expected, for your sensor glucose readings and BG readings to be different but for the most part they should be close. Learn more here.
One thing to keep in mind is that when you check your BG other CGMs automatically change the sensor number to match the BG number. This does not necessarily mean it’s more accurate. Often, it doesn’t make sense to just match the BG since the sensor is measuring glucose from interstitial fluid, a different part of the tissue (not the blood). Our sensors take into account multiple factors in the calibration to provide an accurate glucose sensor reading.
Myth 3: CGM is only about knowing your glucose levels at all times.
Reality: Actually, CGM is a lot more than just readings every five minutes. Yes, sensor glucose readings and threshold alerts let you know where you are at in any given moment or where you’ve been – but more advanced CGM systems can mimic some of the functions of a healthy pancreas by stopping insulin when your sensor glucose level reaches or goes below a preset limit. With SmartGuard™ technology, exclusive to Medtronic devices, CGM can now do more than just alert you, it takes action to reduce lows* without increasing A1C levels** 1 . Learn more here.
In addition, the newly approved MiniMed ® 670G system, the world’s first hybrid closed loop system, comes with a brand new sensor. The Guardian ® Sensor 3 is our most advanced sensor with enhanced accuracy and performance and a 7-day life. It’s the first and only sensor approved by the FDA to control a hybrid closed loop system and it incorporates diagnostic technology that continuously monitors sensor health.
Myth 4: Wearing CGM will give me information overload.
Reality: With alerts, graphs, and sensor glucose readings occurring every 5 minutes, it may seem like your CGM devices give a lot of information at first, but with the right product training and an explanation of how to use the information, you will have the tools to help you take control of your glucose management. To help you ease into it, you may want to turn off the alerts for the first few weeks. We recommend working closely with your diabetes healthcare team to make sure you have the right settings in place, and over time you will gain the expertise to use the more advanced features like predictive alerts or rate of change. Take it at your own pace so you can get the most out of the therapy and ultimately help fine tune your glucose management.
Myth 5: Data from CGM can only be viewed on my pump screen or monitor.
Reality: Your CGM data can be viewed by your healthcare provider and care network in a variety of ways. One option is therapy management software, which for Medtronic is called CareLink ® software. CareLink software creates reports that can help you and your doctor discover trends and patterns, so that you may adjust your personal treatment plan.
Did we answer your questions? Ready to get started on CGM? Click here to learn more about the world’s first hybrid closed loop insulin delivery system, the MiniMed® 670G system.
* Measured as sensor glucose values.
** Based upon limited sample size and duration of ASPIRE In-Home study
1 Bergenstal RM, Klonoff DC, Garg SK, et al. Threshold-based insulin-pump interruption for reduction of hypoglycemia. N Engl J Med. 2013;369(3):224–232.
Important Safety Information: MiniMed® 670G System
The Medtronic MiniMed 670G system is intended for continuous delivery of basal insulin (at user selectable rates) and administration of insulin boluses (in user selectable amounts) for the management of type 1 diabetes mellitus in persons, fourteen years of age and older, requiring insulin as well as for the continuous monitoring and trending of glucose levels in the fluid under the skin. The MiniMed 670G system includes SmartGuard technology, which can be programmed to automatically adjust delivery of basal insulin based on continuous glucose monitor sensor glucose values, and can suspend delivery of insulin when the sensor glucose value falls below or is predicted to fall below predefined threshold values. The system requires a prescription. The Guardian Sensor (3) glucose values are not intended to be used directly for making therapy adjustments, but rather to provide an indication of when a fingerstick may be required. A confirmatory finger stick test via the CONTOUR®NEXT LINK 2.4 blood glucose meter is required prior to making adjustments to diabetes therapy. All therapy adjustments should be based on measurements obtained using the CONTOUR®NEXT LINK 2.4 blood glucose meter and not on values provided by the Guardian Sensor (3). Always check the pump display to ensure the glucose result shown agrees with the glucose results shown on the CONTOUR®NEXT LINK 2.4 blood glucose meter. Do not calibrate your CGM device or calculate a bolus using a blood glucose meter result taken from an alternative site (palm) or from a control solution test. Do not calibrate your CGM device when sensor or blood glucose values are changing rapidly, e.g., following a meal or physical exercise. If a control solution test is out of range, please note that the result may be transmitted to your pump when in the “Always” send mode. WARNING: Medtronic performed an evaluation of the MiniMed 670G system and determined that it may not be safe for use in children under the age of 7 because of the way that the system is designed and the daily insulin requirements. Therefore this device should not be used in anyone under the age of 7 years old. This device should also not be used in patients who require less than a total daily insulin dose of 8 units per day because the device requires a minimum of 8 units per day to operate safely. Only use rapid acting U100 insulin with this system. Pump therapy is not recommended for people whose vision or hearing does not allow recognition of pump signals and alarms. Pump therapy is not recommended for people who are unwilling or unable to maintain contact with their healthcare professional. The safety of the MiniMed 670G system has not been studied in pregnant women. For complete details, including product and important safety information concerning the system and its components, please consult http://www.medtronicdiabetes.com/important-safety-information#minimed-670g and the appropriate user guide at http://www.medtronicdiabetes.com/download-library.
MiniMed is a registered trademark and SmartGuard is a trademark of Medtronic, MiniMed Inc.
Ascensia, the Ascensia Diabetes Care logo and Contour are trademarks and/or registered trademarks of Ascensia Diabetes Care.
MiniMed Connect is intended to provide a secondary display of CGM and insulin pump information on a suitable consumer electronic device to care partners and users of a MiniMed 530G system or Paradigm REAL-Time Revel system for the purposes of passive monitoring.
MiniMed Connect is not intended to replace the primary display of continuous glucose monitoring and insulin pump information on the primary display device. All therapy decisions should be based on blood glucose measurements obtained from a blood glucose meter. MiniMed Connect is not intended to receive information directly from the sensor or transmitter of the sensor-augmented pump system.
Please visit www.medtronicdiabetes.com/importantsafetyinformation for more details.