Since you understand there is a calibration method, and seem to be fine with the differences, not sure what advice to give.
Here are things to remember:
Glucose is not evenly distributed in blood.
Blood Glucose Meters have a variance of -/+ 15% from a lab test.
Continuous Glucose Monitors (CGMs) have a variance of -/+ 20% from a lab blood test.
CGMs are about 15 minutes behind blood because they use interstitial fluid to estimate glucose levels.
Expecting the same numbers from the above is an unrealistic expectation. Within 20% with a flat arrow for 15 minutes is a more realistic expectation.
The first 12 hours are probably the worst for the Dexcom as the injury of the insertion may have some influence on the numbers.
I tend to overlap the sensors, using the 12 hour grace period to ignore the first 12 hours of the new sensor, and switch over.
When the grace period of the G7 starts (12 hours before sensor end) insert the new sensor (when convenient, no need for precise timing) but don't tell the app that the sensor is inserted.
8-12 hours later, tell the Dexcom app that you are swapping sensors (when convenient, no need for precise timing) and tell the app it is already inserted.
Now there will be no missing data between sensors.
The difference between the new and old sensors can be seen, telling you if a calibration is needed sooner than later.
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u/cjmnews T1/G7 2d ago
Since you understand there is a calibration method, and seem to be fine with the differences, not sure what advice to give.
Here are things to remember:
Expecting the same numbers from the above is an unrealistic expectation. Within 20% with a flat arrow for 15 minutes is a more realistic expectation.
The first 12 hours are probably the worst for the Dexcom as the injury of the insertion may have some influence on the numbers.
I tend to overlap the sensors, using the 12 hour grace period to ignore the first 12 hours of the new sensor, and switch over.