NEWER CONTINUOUS GLUCOSE MONITORING SYSTEMS

ABSTRACT

“Newer Continuous Glucose Monitoring Systems” Satish K. Garg, MD Professor of Medicine and Pediatrics, Director of adult Diabetes program, University of Colorado Denver and Barbara Davis Center for Diabetes, Aurora, Colorado. Over the past decade there have been many advances in diabetes technologies, such as Continuous Glucose Monitoring devices/systems (CGMs), insulin-delivery devices, and hybrid closed-loop systems. There have been significant advances in CGMs in the past decade. In fact, ten years ago very few people use to believe in the use of CGMs, even though they had been available for the past two decades. Many providers used to question who, why, and when will patients ever use CGMs similar to the questions asked about Self-Monitoring of Blood Glucose (SMBG) about four decades ago. At the time of this writing, more than five million people world-wide are using a CGM for their diabetes management, especially those who require insulin (all patients with Type 1 diabetes (T1D) and about 20% of patients with Type 2 diabetes (T2D)). Total sales of all CGMs now exceeds more than $7 billion and the use of SMBG is going down every day. Most of the CGMs have improved their accuracy significantly in the past two decades. I still remember doing studies on the GlucoWatch and earlier versions of Dexcom STS where mean absolute relative difference (MARD) used to be in the range of 15-26%. Now most of the CGMs (Guardian by Medtronic, G6 by Dexcom, and Libre 2 by Abbott) have single-digit MARD. In addition, the majority of the new CGMs do not require calibrations and the newer CGMs last for 10-14 days. An implantable CGM by Senseonics (Eversense®) is approved in the USA for 3 months and a different version is approved in Europe for 6 months. FDA has still not approved the 6-month version of Eversense® implantable sensor in the USA, which also has single-digit accuracy. The newer CGMs that are likely to be launched in the next 3-6 months;hopefully around the ATTD Conference, include 10.5-day Dexcom G7 (60% smaller than the existing G6), 7-day Medtronic Guardian 4, 14-day Libre 3, and 6-month Eversense®. Most of the newer CGM data can be viewed on Android or iOS/iPhone smart devices, and in many instances they have several features like predictive alarms and alerts, easy insertion, automatic initialization (in some instances down to 27 mins, Dexcom G7) with single-digit MARDs. It has also been noticed that arm insertion site might have better accuracy than abdomen or other sites like the buttock for kids. Lag time between YSI and different sensors have been reported differently, sometimes it's down to 2-3 mins;however, in many instances, it's still 15-20 mins. Diabetes effects communities of color disproportionately higher. For example, the highest prevalence of diabetes in the USA is amongst Native Americans (14.7%), which is nearly two times higher than Caucasians. African Americans and Hispanics also have higher prevalence of diabetes in the USA. It's also known that LatinX, African Americans, and Native Americans are much less likely to be offered new technologies like continuous subcutaneous insulin infusion (CSII/insulin pumps) and CGMs. Use of technology, especially CGMs, is expected to remove many of the social barriers and disparities in care for people with diabetes. A large database during the COVID-19 pandemic recently reported better Time-in-Range (TIR) in patients with diabetes irrespective of their ethnic background. However, the baseline TIR was significantly lower for minorities as compared to Caucasians. I believe the future will bring a larger increase in the use of CGMs for people with insulin-requiring diabetes (estimated at more than 100 million people globally) and those with T2D on non-insulin therapies (estimated at more than 400 million people globally). I also envision an increase in the number of pre-diabetes patients (estimated at more than 200 million people globally) using CGMs so that early medical intervention for diabetes management can be entertained. The intermittent or continuou use of CGM would depend upon the clinical needs. Needless to say, healthy individuals without diabetes (who can afford CGMs) might even use these technologies for self-evaluation of their glucose profiles after meals.