To evaluate the association between Flash Glucose Monitoring (FLASH) frequency and glycemic parameters during real-life circumstances in the Netherlands. Methods: Obtained glucose readings were de-identified and uploaded to a dedicated database when FLASH reading devices were connected to internet. Data between September 2014 and March 2020, comprising 16,331 analyzable readers (163,762 sensors) were analyzed. Scan rate per reader was determined and each reader was sorted into 20 equally sized rank ordered groups (n = 817 each). Results: Users performed a median of 11.5 ] scans per day. Those in the lowest and highest ventiles scanned on average 3.7 and 40.0 times per day and had an eHbA1c of 8.6% (71 mmol/mol) and 6.9% (52 mmol/mol), respectively. Increasing scan rates were associated with more time in target range (3.9-10 mmol/L), less time in hyperglycemia (>10 mmol/L), and a lower standard deviation of glucose. An eHbA1c of 7.0% (53 mmol/mol) translated in approximately 65% time in target range, 30% time in hyperglycemia and 5% time in hypoglycemia (<3.9 mmol/L). Conclusions: These outcomes among Dutch FLASH users suggest that with higher scan rate glycemic control improves.

Background Real time Continuous Glucose Monitoring (rt-CGM) is used by patients with type 1 diabetes mellitus (T1DM) during various circumstances. Limited data is available concerning the performance of the widely used Dexcom G6 rt-CGM during moderate exercise. Methods Prospective, investigator-initiated study to test the performance of the Dexcom G6 rt-CGM during moderate exercise. Seventeen participants with T1DM went hiking for 6 days, followed by 6 days of normal daily activities (NDA). Capillary glucose measurements were performed with Precision Neo Pro strips; previously verified to be closely comparable with the gold reference method. Results Two persons dropped out of the study and 4 had incomplete data. Consequently 11 participants with a median age of 55 [interquartile range 39-62] years, 91% female and median HbA1c 55 [interquartile range 40-75] mmol/mol were analyzed. During moderate exercise the mean absolute differences and mean absolute relative differences of the Dexcom G6 rt-CGM were 20±17 mg/dl and 16±15%. Overall, the Dexcom G6 rt-CGM reported higher glucose concentrations, compared to capillary measurements, during exercise (154±64 vs. 149±70 mg/dl (p<0.001)). When assessing accuracy during exercise compared to the capillary measurements using Parkes error grids, 98.6% of the comparisons fell within zones A and B. According to the Integrated Continuous Glucose Monitoring Approvals (Class II–510(K)) guidelines, the Dexcom G6 rt-CGM did not reach the agreed upon cut-off levels and were more or less comparable as during NDA. Conclusions Despite limitations, this study demonstrates that during moderate exercise the Dexcom G6 rt-CGM does not meet current benchmark criteria. Trial registration: This study was approved by the Medical Ethical committees in The Netherlands (Isala Hospital; NL70456.075.19/190605) and in Spain (CEIm de las Áreas de Salud de León y del Bierzo; no.1981). Registered at www.trialregister.nl: NL7922.