Real-world outcomes of continuous glucose monitoring in adults with diabetes mellitus attending an Irish tertiary hospital

Abstract

Backgrounds and aims: The American Diabetes Association/European Association for the Study of Diabetes recently recommend the preferential use of continuous glucose monitoring(CGM) over self-monitoring of blood glucose for the management of type 1 diabetes (T1DM). For most adults with T1DM, the recommended target time in range is > 70% with < 4% time below range. In Ireland, CGM use has become increasingly popular since 2021. We aimed to audit adult CGM use and analyse CGM metrics in our cohort of adults with diabetes attending a tertiary diabetes centre. Methods: People with diabetes who were using DEXCOM G6 CGM devices, and sharing their data with the healthcare team on the DEXCOM CLARITY for healthcare professionals platform were included in the audit. Clinical information, glycated haemoglobin (HbA1c) and CGM metrics were gathered retrospectively from medical records and the DEXCOM CLARITY platform. Results: Data were available for 119 CGM users, 96.9% with T1DM, median age 36 years (IQR = 20) and median diabetes duration 17 years (IQR = 20). Fifty-three per cent of the cohort was male. Mean time in range was 56.2% (SD = 19.2) and mean time below range was 2.3% (SD = 2.6). Mean HbA1c in CGM users was 56.7 mmol/mol (SD = 13.1). This represented a decrease of 6.7 mmol/mol compared to the last HbA1c measurements available pre-commencement of CGM (p ≤ 0.0001, CI 4.4–8.9). The percentage of people in this cohort with a HbA1c < 53 mmol/mol was 40.6% (n = 39/96), compared to 17.5% (n = 18/103) pre-commencement of CGM. Conclusions: Our study highlights the challenges in optimising the use of CGM. Our team aims to focus on providing additional education to CGM users, more frequent touch-base virtual reviews and increasing access to hybrid closed-loop insulin pump therapy.