Flash Glucose Monitoring: The Future Is Here

We cannot believe that it has been more than two decades since we first evaluated real-time continuous glucose monitoring (CGM)—(GlucoWatch ) in patients with type 1 diabetes (T1D). The first real-time CGM (GlucoWatch), which uses a reversed iontophoresis to measure interstitial glucose, was approved to be used for 12 h by the Food and Drug Administration (FDA) in 1999. Since then, several advancements have led to the availability of many CGM systems MiniMed iPro , Enlite 2 , Enlite Enhanced, Enlite 3 (Medtronic, Northridge, CA), DexCom STS (Short Term Sensor), Dexcom 3, 7, Gen 4 and 5 (Dexcom, San Diego, CA), and Navigator (Abbott Diabetes Care, Alameda, CA). All of the CGMs were approved as adjunctive and needed 2–4 calibrations a day. Bailey et al. highlighted the accuracy of CGMs and clinical implications of accuracy in this supplement. Most recently, for the first time, Dexcom Gen 5 was approved as nonadjunctive, and CGM data could be used for insulin dosing decisions, although it still needs 2 calibrations a day. Large, multicenter, randomized clinical trials that showed the utility of using CGM were detailed by Slattery et al. in this supplement. The first major breakaway came with the launch of FreeStyle Libre Pro (professional) or personal—a patch glucose sensor, needing no calibration (factory calibrated) that lasts for 14 days. FreeStyle Libre professional or personal, commonly referred to as ‘‘flash glucose monitoring’’ system, where the data are available on demand at any time during 14 days and needs no calibration during its use. Only FreeStyle Libre Pro is currently approved by FDA for professional use. Wright et al. emphasized the benefits of flash glucose monitoring professional use with real case series in this supplement. The flash glucose monitoring has had a significant uptake in European countries wherever it has been made available. In fact, more recently, I had two of my patients who bought their flash glucose monitoring personal in Europe, and they were very ‘‘impressed’’ with its accuracy, ease of use, and liked that flash glucose monitoring did not need any calibrations. There are many reasons for early success and rapid uptake of flash glucose monitoring. These include the following: Lowest cost of a CGM system (flash glucose monitoring) No calibration needed (I can’t emphasize this enough as it is a big deal for most patients) First 14-day factory-calibrated flash glucose monitoring Reliable and accurate data available on demand throughout its use Similar (lower) MARD (mean absolute relative difference) throughout 14 days of use