(267) Real-World Continuous Glucose Monitoring in Adults with Type 1 and Type 2 Diabetes

Saturday, August 27, 2022

8:00 AM – 6:00 PM CEST

Location: Hall C

Publication Number: 941

Presenting Author(s)

Devin Abrahami, PhD
– Research Fellow, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States

Co-Author(s)

Sonia Hernandez-Diaz, MD, MPH, FISPE
– Professor of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, United States
Elisabetta Patorno
– Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA, United States

Background: Monitoring blood glucose in patients with diabetes is crucial to optimize glucose control and minimize the risk of diabetic complications, particularly hypoglycemia. Continuous glucose monitoring (CGM) systems automatically track blood glucose levels, which may help patients make more informed decisions regarding their glucose control. Most of the evidence on the effectiveness of CGM systems is in patients with type 1 diabetes (T1D). However, the indications and guidelines for CGM systems are evolving, with some experts recommending their use in all patients who use insulin, regardless of diabetes type. Thus, it is important to characterize the utilization of CGM systems and their impact on the rate of hypoglycemia in the real-world setting.

Objectives: The objective of this ecological study was to assess temporal trends in CGM system use and evaluate whether these trends correlate with trends in hypoglycemia and HbA1c levels in insulin users with T1D and type 2 diabetes (T2D), separately.

Methods: From January 1, 2016, through January 1, 2021, we created a series of 11 cohorts (one for every six months of calendar time) of patients with a diagnosis of T1D and a recent history of insulin use. Within each cohort, we assessed the prevalence of CGM system use and the rate of hypoglycemia in the six months after cohort entry. In the subset of patients with a recorded HbA1c during baseline, we measured the mean HbA1c during follow-up as an alternate measure of glycemic control. All analyses were repeated in cohorts of patients with T2D and recent insulin use.

Results: The prevalence of CGM use increased from 6.4% to 27.0% among patients with T1D from 2016 to 2021. However, the rate of diagnosed hypoglycemia slightly increased in patients with T1D from 2016 (11.2/1000 person-years) to 2021 (18.9/1000 person-years). In patients with a recorded HbA1c level at baseline, there was a decrease in the percentage of patients with severe hyperglycemia (HbA1c > 8.0%) during the study period, from 53.5% in 2016 to 40.8% in 2021. In contrast, the prevalence of CGM use was much lower in patients with T2D, though it increased from 0.6% in 2016 to 3.8% in 2021. Similarly to T1D, the rate of diagnosed hypoglycemia in T2D slightly increased from 30.6/1000 person-years in 2016 to 39.1/1000 person-years in 2021. However, the percentage of patients with severe hyperglycemia was relatively consistent in patients with T2D (33.4% in 2016 to 28.8% in 2021).

Conclusions: The results of this study suggest that the increase in the use of CGM systems in insulin users with T1D and T2D does not correlate with a reduction in the rate of hypoglycemia at the population level, but does correlate with a reduction in the rate of hyperglycemia in patients with T1D. More careful selection of patients who might most benefit most from CGM use is warranted.