Future of CGM Technology Looks Bright

Individuals with diabetes, whether its type 1 or type 2, must check their blood sugar regularly to keep that and their A1c levels monitored and under control.

Some patients test once a day, some more than 6 times a day. Pricking their fingers many times, can present a challenge for patients. Some have issues with compliance and remembering to test, some are scared of the pain from finger pricking, and others have trouble arranging their daily activities and chores around testing their blood sugar levels and managing the disease.

In recent years, many improvements have occurred in terms of testing blood sugars. It started in the 1800s when there were attempts to quantify glucose levels in the urine. This created the basis for testing blood sugars for patients with diabetes. In 1908, for the first time, the Benedict urine glucose copper reagent was developed, becoming the go-to test for next 50 years. In 1945, the Ames Co. developed the Clinitest, which featured a tablet version of the copper reagent. In 1965, Ames developed the first blood glucose test strip, called Dextrostix, following by the first blood glucose meter in 1970, that used Dextrostix. Dextrometer, the first meter with digital display came to market in 1980s. From that moment, self-monitoring of blood glucose (SMBG) became the standard of care, especially for patients with type 1 diabetes.¹

The evolution and progress of home glucose monitoring continued and was revolutionized even more, with the introduction of continuous glucose monitoring (CGM). In 1999, the FDA approved the first CGM in the market, and the first real-time CGM was Glucowatch Biographer, which was worn as a wristwatch. This device used reverse iontophoresis measuring glucose levels. In 2004, Medtronic introduced the Guardian CGM, which was advanced enough to show hyperglycemia and hypoglycemia. Medtronic then introduced the iPro CGM in 2008 and MiniMed 530G Enlite closed loop system in 2013. In 2017, Medtronic’s first hybrid closed-loop device was released using the Guardian Sensor 3. Following Guardian, in the same year, Dexcom introduces its CGM called Short-Term Sensor (STS). This was followed by the release of the FreeStyle Navigator CGM by Abbott in 2008. Dexcom introduced the G4 CGM in 2012 and then the G5 and G6 in 2018. Abbott also introduced the FreeStyle Libre Pro in 2016, the first CGM of its kind that did not require any fingerstick. Abbott then moved on to Libre 10 days, 14 days, and to Libre 2.

Dexcom started with the G4 model, moving to G5 and then G6, as its current version. The G6 model benefits include approval for up to 10 days of use, long-life sensor use, and no calibration required. Another benefit is that the Dexcom G6 sensors prevent clinically significant interference from acetaminophen, which has shown previously to affect blood sugar readings. It has a simple sensor insertion with an auto-applicator, using a 1-button push insertion. It also has an urgent-low-soon alert, which provides 20-minute advance warning of a potential severe hypoglycemic event, as well as 2 alert schedules, which can be customized for 2 periods of time within 24 hours for day and night schedules. The sensor is water-resistant, and with the Dexcom CLARITY data system, patients can view the data, statistics, and trends, and communicate that information to their health care providers.²

Abbott’s libre was available in a 10-day sensor, then a 14-day system called freestyle Libre, and it recently introduced the Libre 2 system. The Libre 14-day system takes the reading after just a 1-hour warmup, with sensor wear time of 14 days, making it the longest-lasting self-applied sensor in the market. The FDA recently cleared the Libre 2 for adults and children ages 4 years and above, which expands the use of the Libre system to many more patients, especially the pediatric population. The Libre 2 comes with real-time glucose alarms that notify patients of highs and lows. It also provides an alert on the loss of a signal between the reader and sensor.³

Medtronic’s Guardian Sensor 3 offers sensor-integrated pump therapy and standalone CGM. It offers up to 7 days of sensor life and a shorter start-up time. It can be worn on either the abdomen or on the back of the arm. This CGM sensor is compatible with the MiniMed 630G and MiniMed 670G insulin pumps. The Guardian Connect CGM system is another standalone CGM system from Medtronic, which allows patients to get alerts for up to 60 minutes in advance for highs and lows, see glucose levels and trends, and connect and share the information with health care providers.⁴

Eversense CGM from Senseonics, is the only 90-day implantable CGM system on the market. Eversense, has an under-the-skin sensor, uses a removable and rechargeable water-resistant smart transmitter, and patients need to charge it just 4 times a year. It also provides on-body vibrations to alert patients to potentially dangerous swings in blood sugar levels, which is helpful when patients are sleeping or do not have access to their phones. The transmitter can be removed and replaced without the sensor change. The 3.5 mm x 18.3 mm penny-size sensor insertion and removal require an incision in a physician’s office.⁵

With all the new CGM technology, the future of testing blood sugars for patients with diabetes looks very bright. Not only are the patients able to use these CGMs and be aware of their blood sugar levels throughout the day, they are able to connect their health care providers to these data and readings. The near future will bring the updated version of the CGMs to market, as well as many new manufactured CGMs that are being introduced.

Saro Arakelians, PharmD, is the general manager and pharmacist in charge at BioScrip Infusion in Burbank, California.

References

• Hirsch IB. Introduction: history of glucose monitoring. In: role of continuous glucose monitoring in diabetes treatment. Arlington (VA); American Diabetes Association: 2018. https://www.ncbi.nlm.nih.gov/books/NBK538968/ doi: 10.2337/db20181-1
• Dexcom. Accessed September 22, 2020. https://www.dexcom.com/g6/features-and-benefits
• Freestyle Libre. Accessed September 22, 2020. https://www.freestylelibre.us/system-overview/freestyle-libre-2.html
• The Guardian Connect System. Medtronic.com. Accessed September 22, 2020. https://www.medtronicdiabetes.com/products/guardian-connect-continuous-glucose-monitoring-system
• Senseonics. Accessed September 22, 2020. https://www.senseonics.com/