Background: New features of continuous glucose monitoring (CGM) systems may have measurable effects on usage and outcomes. The G5 and G6 CGM systems (Dexcom, Inc.) are comparably accurate and have adjustable low threshold alerts. A principal difference between the systems is that G6 introduces the “Urgent Low Soon” (ULS) alert, which is enabled by default and triggered when an estimated glucose value (EGV) ≤55mg/dL is predicted in the next 20 minutes. We evaluated the impact of the ULS alert by comparing data from patients who transitioned from G5 to G6.
Methods: We examined device settings and EGVs from an anonymized convenience sample of 1424 patients who used G5 and transitioned to G6 between 5/1/18 and 8/31/18. Data from users with the low threshold alert setting of 70mg/dL (n=658) or 80mg/dL (default; n=766) were evaluated separately. Receiver users, those who disabled the ULS alert, or those with less than 30 days of data immediately preceding or following the transition to G6 were excluded.
Results: The ULS alert remained enabled among >97% of G6 users and was triggered less than once daily (Table). Hypoglycemia (<55mg/dL and <70mg/dL) and severe hyperglycemia (>250mg/dL) decreased significantly after transitioning to G6, whether users had a low threshold alert set at 70mg/dL or 80mg/dL. Time in range improved significantly for users with a low threshold alert set at 70mg/dL, but not at 80mg/dL.
Conclusion: The ULS alert of the G6 CGM system may contribute to significant reductions in hypoglycemia and improved glycemic control among CGM- experienced users.