ADA 2021 Expert Perspective: Dr. Diana Isaacs's Top 5 CGM Studies

Ahead of ADA 2021, Endocrinology Network reached out to Diana Isaacs, PharmD, Clinical Pharmacy Specialist and the Remote Monitoring Program Coordinator at the Cleveland Clinic, to take part in our coverage of the annual meeting. Isaacs compiled a list and created a video detailing her top picks for CGM-related data presented at the conference.

Study 1

597-P: Long-Term A1C Outcomes with and without Intermittent CGM Use in Adults with T2D Participating in the Onduo Program

By Jennifer Layne, PhD, et al.

• Virtual Diabetes Clinic offers remote care, including a mobile app, remote lifestyle coaching, video consultations with endocrinologists, to type 2s.
• Patients who are “high risk” are also offered prescriptions for intermittent-use Dexcom G6 CGMs.
• This retrospective analysis included baseline, six-month, and one-year data from 772 participants, of whom 46% (n=354) used CGM and 54% (n=418) did not use CGM.
• Dexcom G6 users saw a 0.7% A1c reduction to 7.2% at one year, a significantly greater improvement relative to those not using CGM, who saw only a 0.2% reduction to 7.4% (p<0.001).
• Even more impressive, CGM users with baseline A1c values >9% saw a 2.8% A1c reduction to 8.0% at one year, a significantly greater improvement relative to a 1.8% reduction to 9.0% among non-CGM users (p=0.006).
• Included people with type 2 diabetes not on insulin.

Study 2

Successful Use of CGM in Primary Care Depends on Patient Support and Workflow-Lessons from the Mobile Study

Presented during a symposium by Thomas Martens, MD

• Effect of CGM on Glycemic Control in Patients with Type 2 Diabetes Treated with Basal Insulin
• RCT in 15 clinical centers throughout US
• Recruited individuals in primary care practices
• Compared rtCGM vs BGM in management of T2D on basal insulin
• Primary outcome: A1C at 8 months
• Enrollment: age >30 years, A1C 708-11.5, basal insulin with any other therapies (no prandial)
• Randomized 175 individuals 2:1 to CGM vs BGM
• Average age 57, 53% minor rate or ethnicity, mean A1c=9.1%
• Dexcom G6
• BGM used: one touch verio flex
• 8-month study
• Advisors reviewed data and forwarded to primary care clinician
• All active diabetes management iremianed in primary care.
• Findings: greater decrease in A1C over 8 months in CGM vs glucose monitors (1.1% vs -0.6%).
• CGM group had significantly better time in range 70-180.
• Strategies for implementing CGM technology: get access to the data, use the data, cadence of titration

Study 3

Accuracy of Dexcom G6 Continuous Glucose Monitoring in Non–Critically Ill Hospitalized Patients With Diabetes

Presented at a Dexcom sponsored section by Guillermo Umpierrez, MD

• Dr. Umpierrez read out the data that showed Dexcom G6 is accurate in hospital settings.
• The newly published retrospective study, which included 205 insulin-treated type 2 diabetes patients wearing Dexcom G6 in general medicine and surgery wards, found that 98.6% of data fell in Zones A and B of a Clarke Error Grid.
• The researchers found no difference in accuracy based on race, BMI, arm vs. abdomen placement, and eGFR.
• However, the MARD was significantly higher in the hypoglycemic range (<70 mg/dl) at ~18%, as compared to ~11%-12% at all other glycemic ranges.
• Dr. Umpierrez noted that this issue may suggest that providers should perform point-of-care testing when CGM readings <80 mg/dl in hospital settings.
• The accuracy also dropped significantly in patients with severe anemia (hemoglobin <7 g/dl) with a MARD of ~17%.
• Looking ahead, Dr. Umpierrez highlighted a G6 intervention study comparing the glycemic control achieved through insulin adjustment by point-of-care testing vs. insulin adjustment by CGM readings in hospitalized insulin-treated type 1s and type 2s. Per Dr. Umpierrez, the study has just completed, and we’ll be keeping an eye out for its publication.

Study 4

600-P: Real-Time CGM Coverage Eligibility Should Include Type 2 Diabetes Patients Treated with Less-Intensive Therapy

By Thomas Grace, MD

• Investigator-initiated, 6-month, prospective, interventional, single-arm study assessed the effects of rtCGM use in T2D patients treated with basal insulin only or non-insulin.
• Clinic visits occurred at baseline and every 3 months per usual care.
• The primary outcomes were changes in A1C and percent of time in range (%TIR), above range (%TAR) and below range (%TBR).
• Largely Caucasian population (97.4%)
• Baseline A1C=10.1%
• 3 months, -2.8% reduction
• 6 months, -3% reduction
• Time in range increased from 57% to 68.4% 3 months) to 72.2% at 6 months
• Expanding insurance coverage to T2D patients treated with less-intensive therapy may help improve glycemic control within the broader diabetes population.

Study 5

136-LB: Budget Impact of Adding Flash Continuous Glucose Monitoring (CGM) to Medicaid Formularies

By Jeffrey Frank, MD, et al.

• The authors compared the cost of increased FreeStyle Libre adoption against the cost savings resulting from reduced severe hypoglycemia and DKA events.
• With nearly 1.1 million people on intensive insulin therapy enrolled in Medicaid (~370,000 type 1s and ~690,000 type 2s), the calculation assumed FreeStyle Libre adoption in this group would grow from a hypothetical 23% to 33% with universal coverage for FreeStyle Libre.
• This would result in an extra $121 million in cost to cover glucose monitoring in this population per year. Using published data, the analysis then assumed rates of DKA and severe hypoglycemia events would be cut by ~50% for those who initiated FreeStyle Libre. This would result in cost savings of $74 million per year.
• Additionally, the calculation assumed FreeStyle Libre would deliver an A1c reduction of ~0.5% for type 1s and ~0.9% for type 2s; this would result in annual cost savings of $66 million.
• Adding things up, the calculation estimates $19 million in annual cost savings for national Medicaid expenditure.