New Glucose Monitoring System May Increase Time in Target Glucose Range for Patients with Type 1 Diabetes

A continuous glucose monitoring system may allow patients with type 1 diabetes to have longer periods in target glucose levels and decrease the risk of complications from hyperglycemia.

Intermittently scanned continuous glucose monitoring with alarms safely decreased high glycated hemoglobin levels in patients with type 1 diabetes, which resulted in patients having a reduced burden of hypoglycemia, according to a study published in The New England Journal of Medicine.

“Among participants with type 1 diabetes and high glycated hemoglobin levels, the use of intermittently scanned continuous glucose monitoring with optional alarms for high and low blood glucose levels resulted in significantly lower glycated hemoglobin levels than levels monitored by fingerstick testing,” the study authors wrote.

People with type 1 diabetes need to constantly check glycated hemoglobin levels (a glycemia marker) to guide their insulin dosage. If glycated hemoglobin levels are frequently too high, it can elevate the risk of major complications. Target levels for glucose blood levels vary between 70 and 180 mg per deciliter.

Traditionally done via fingerstick testing, studies have found that continuous glucose monitoring systems, either intermittently scanned or real-time system, can track glucose levels without the use of a fingerstick.

Researchers identified a knowledge gap in understanding the efficacy of intermittently scanned continuous glucose monitoring with optional alarms for high and low blood glucose levels among patients with type 1 diabetes. Specifically, researchers studied whether the use of this system would reduce glycemia in patients with high glycated hemoglobin levels and increase treatment satisfaction more than fingerstick testing.

The primary end point was glycated hemoglobin level at 24 weeks, results being analyzed according to the intention-to-treat principle. The key secondary end points were sensor data, participant-reported outcome measures, and safety.

The FLASH-UK trial was a 24-week, open-label, parallel-group, multicenter, randomized, and controlled trial that compared the efficacy of intermittently scanned continuous glucose monitoring against the placebo in 156 patients.

The results show that those in the intervention group had target blood glucose levels that lasted 130 minutes longer than those who were not in the intervention group. The intervention group also experienced less time in a hypoglycemic state, in which blood sugar levels are less than 70 mg per deciliter. Time in hypoglycemia was 43 minutes shorter for participants in the intervention group than those in the control.

The current trial found that intermittently scanned continuous glucose monitoring with optional alarms only administered daily insulin doses that were generally small, “which suggests that participants may have been able to use continuous glucose monitoring to adjust their own insulin levels effectively,” the study authors wrote.

Two participants had severe hypoglycemia and there were 6 cases of ketosis, but overall, the risk of severe adverse events was low throughout the trial.

Limitations to the study included a lack of sensitivity to assumptions, a majority White demographic that limited generalization ability, and some participants were virtual due to the COVID-19 pandemic, which caused testing to be done at home and not in the lab. Additionally, severe (or unaware) hypoglycemic participants were excluded.

”The benefit with respect to glycated hemoglobin levels was robust in a range of sensitivityanalyses, …and cost-effectiveness analysis is under way,” the study authors wrote.


Leelarathna, L., Evans, M.L., Neupane, S., et al. Intermittently Scanned Continuous Glucose Monitoring for Type 1 Diabetes. October 5, 2022. The New England Journal of Medicine. DOI: 10.1056/NEJMoa2205650