From the Guidelines
The main difference between FreeStyle Libre 2 and Dexcom G7 is that FreeStyle Libre 2 is an intermittently scanned continuous glucose monitoring (isCGM) system, also known as a "flash" glucose monitoring system, which requires scanning to display glucose levels, whereas Dexcom G7 is a real-time continuous glucose monitoring (rtCGM) system that measures and displays glucose levels continuously without the need for scanning 1.
Key Features of Each System
- FreeStyle Libre 2:
- Measures glucose levels continuously but requires scanning for visualization and storage of glucose values
- Does not provide real-time glucose alerts, but some versions may have alarms
- Lower direct costs compared to rtCGM systems
- Factory calibrated and does not require calibration with self-monitoring of blood glucose (SMBG)
- Dexcom G7:
- Measures and displays glucose levels continuously in real-time
- Provides real-time glucose alerts and alarms for high and low glucose levels
- Generally considered more convenient than isCGM systems, but may have higher direct costs
- May be used with automated insulin delivery (AID) systems, such as insulin pumps 1
Clinical Considerations
The choice between FreeStyle Libre 2 and Dexcom G7 should be based on individual circumstances, preferences, and needs 1. For example, individuals who require more frequent glucose monitoring and real-time alerts may prefer Dexcom G7, while those who prioritize lower costs and are willing to scan their device regularly may prefer FreeStyle Libre 2. Ultimately, the decision should be made in consultation with a healthcare provider, taking into account the individual's specific needs and medical history.
From the Research
Overview of FreeStyle Libre 2 and Dexcom G7
- The FreeStyle Libre 2 is a flash glucose monitoring system that measures glucose levels in the interstitial fluid every minute and stores the reading automatically every 15 minutes 2.
- The Dexcom G7 is a continuous glucose monitoring system that provides real-time glucose readings 3.
Key Differences
- The FreeStyle Libre 2 does not require calibration, whereas the Dexcom G7 may require calibration 4, 3.
- The FreeStyle Libre 2 has been shown to be more accurate than the Dexcom G7 in some studies, with a lower mean absolute relative difference (MARD) 3.
- The Dexcom G7 provides real-time glucose readings, whereas the FreeStyle Libre 2 requires the user to scan the sensor to obtain a reading 2.
Comparison of Accuracy
- A study comparing the FreeStyle Libre 3 and Dexcom G7 found that the FreeStyle Libre 3 had a significantly lower MARD than the Dexcom G7 (8.9% vs 13.6%) 3.
- Another study comparing the FreeStyle Libre Pro and iPro2 found that the FreeStyle Libre Pro had a higher MARD than the iPro2 (8.1% vs 5.0%) 5.
- A study comparing the FreeStyle Libre and Dexcom G4 Platinum found that the two sensors had similar accuracy during home use, but the FreeStyle Libre was more accurate during moderate and rapid glucose changes 6.
Clinical Implications
- The choice between the FreeStyle Libre 2 and Dexcom G7 may depend on individual patient needs and preferences, such as the need for real-time glucose readings or the convenience of a calibration-free system 4, 3.
- Both systems have been shown to be effective in improving glycemic control and reducing hypoglycemic events 2, 5.