180-day implantable CGM found safe and effective for managing blood sugar: Study

Diabetes has emerged as a major global health concern over the past few decades. It is a chronic condition that affects the way the body processes blood sugar.

Diabetic patients either don't produce enough insulin, or the body resists insulin. In such patients, regular monitoring of glucose levels is essential. Keeping this in mind Garg's research team conducted the PROMISE study across eight clinical research sites, specifically testing two different sensors used with the CGM system. The study was put forth during the virtual American Diabetes Association (ADA) Scientific Sessions.

It included 181 participants, with an average age of 49. The cohort was split between men and women and more than 90% of the cohort was white. The average duration of diabetes was 22 years. Average baseline HbA1c was 7.6%, and 70% had type 1 diabetes.

The participants had a primary sensor implanted into one arm; one half had an identical sensor placed into the other arm, while the other half had a different sensor placed into the second arm -- a Sacrificial Boronic Acid (SBA) sensor -- which has a specific chemical makeup aimed at reducing oxidation of the glucose-binding indicator chemistry.

Participants were seen at 10 clinic visits that took place during the 180 days of use, each visit lasting up to 10 hours. At these visits, participants underwent hyperglycemic and hypoglycemic challenges to test the full 40-400 mg/dL blood glucose range. CGM readings were compared with a reference glucose reading from a Yellow Springs Instruments (YSI) 2300 glucose analyzer.

Garg and team reported the following findings:

• Average HbA1c improved across the cohort, dropping from 7.6% to 7.3% at day 180.
• only 65% of the primary sensors survived up to the full 180 days of implantation. Nearly all survived to day 90 (98%), 90% were still working by day 120, and only 74% survived to day 150.
• The SBA sensor performed far better, as 90% lasted the entire 180-day wear
• They also were slightly more accurate in regard to hypoglycemia, with a 7.5% and 7.7% mean absolute difference at ranges of 40-60 mg/dL and 61-80 mg/dL
• The SBA sensors also performed better in alerting the patient to hypoglycemia (glucose of 60 mg/dL), with a true alert rate of 73% versus 68% with the primary sensor.

"These CGM are accurate, safe for use up till 180 days and show no serious adverse events with respect to insertion or removal of the devices," the team concluded.

Garg additionally remarked, "Clearly, this biochemical change that has been made in the SBA sensor is probably the future way to go. The majority of the patients can have 6 months of data available to them with one particular implant."

Primary Source

American Diabetes Association

Source Reference: Garg SK, et al "Evaluation of the next generation 180-day long-term implantable Eversense CGM system: PROMISE study" ADA 2021; Abstract 149-OR.