Flash Glucose Monitoring Can Improve Glycemic Control, Time in Range in Type 1 Diabetes

Lalantha Leelarathna, MBBS, MRCP, MSc, PhD

Data from the FLASH-UK trial is providing new insights into the benefits of flash glucose monitoring for improving glycemic control in people with type 1 diabetes.

A randomized controlled trial comparing intermittently scanned glucose monitoring with the FreeStyle Libre 2 flash glucose monitor against usual care, results of the trial suggest use of the flash glucose monitoring was associated with significant reductions in HbA1c levels at 24 weeks and improvements in time in target glucose range.

"Continuous glucose monitoring has been a critical tool for people living with diabetes, both to avoid painful fingersticks and to help manage glucose levels," said lead investigator Lalantha Leelarathna, MBBS, MRCP, MSc, PhD, from the University of Manchester NHS Foundation Trust, in a statement from Abbott. "This data adds to the growing body of evidence that demonstrates the technology helps bring HbA1c levels closer to the target range, which ultimately decreases risks of further complications."

As continuous glucose monitoring (CGM) technology continues to advance, interest has grown surrounding the potential benefits of these systems on glycemic control and other outcomes among people with diabetes. Born out of a desire to further explore the benefits of CGM in type 1 diabetes, the FLASH-UK trial was designed as a parallel-group, multicenter, randomized, controlled trial and randomized 156 people with type 1 diabetes in a 1:1 ratio to intermittently scanned glucose monitoring with the FreeStyle Libre 2 system or usual care, which called for self-monitoring using traditional finger sticks.

People enrolled in the study were at least 16 years of age, had type 1 diabetes for at least 1 year, and an HbA1c of 7.5-11% while receiving either continuous subcutaneous insulin infusion or multiple daily injections. The 156 patients who underwent randomization were recruited from 7 diabetes specialist clinics and a single primary care center in the United Kingdom.

The primary outcome of interest for the study was HbA1c level at 24 weeks. The study also included multiple secondary outcomes, including time per day in target glucose range, time spent in a hypoglycemic state, and multiple safety end points. Investigators noted the primary outcome was assessed in intention-to-treat analyses.

Of the 156 individuals who underwent randomization, 78 were randomized to intermittently scanned continuous glucose monitoring and 78 were randomized to usual care. At baseline, the overall study cohort had a mean age of 44±15 years, a mean duration of diabetes of 21±13 years, and 44% were women.

At baseline, the mean HbA1c was 8.7±0.9% among the intervention arm and 8.3±0.9% among the usual care arm. At 24 weeks, this figure was decreased to 7.9±0.8% and 8.3±0.9% among the intervention and usual care arm, respectively (adjusted mean between-group difference, -0.5 [95% CI, -0.7 to -0.3]; P <.001).

Further analysis indicated time per day spent I target glucose range was 9.0 percentage points (95% CI, 4.7 to 13.3) higher or 130 minutes (95% CI, 68 to 192) longer in the intervention group than in the usual care group, and the time spent in a hypoglycemic state, which was defined as a blood glucose level below 70 mg/dL, was 3.0 percentage points (95% CI, 1.4 to 4.5) lower or 43 minutes (95% CI, 20 to 65) shorter in the intervention group.

"This randomized study clearly illustrates the importance of continuous glucose monitoring for adults with Type 1 diabetes," said Mahmood Kazemi, chief medical officer for Abbott's diabetes care business. "This clinically-significant change in HbA1c levels shows FreeStyle Libre technology empowers people to make lifestyle decisions that improve their glucose control and, ultimately, may result in a reduction in diabetes-related health problems down the line."

This study, “Intermittently Scanned Continuous Glucose Monitoring for Type 1 Diabetes,” was published in the New England Journal of Medicine.