Glucose Differences Between Continuous Glucose Monitor Brands and Application Sites

Abstract

Switching between continuous glucose monitoring (CGM) device brands and application sites is common in clinical practice. We hypothesized that the differences between CGM device measurements are significant enough to impact glycemic control interpretation. Current evidence has identified a trend of clinically meaningful differences between right- and left-arm CGM readings in one CGM device. We also hypothesized that application sites can affect glycemic control interpretation. A case study in which two adult males each wore three Dexcom G6 (right arm, left arm, abdomen) and two FreeStyle Libre Pro (right arm, left arm) CGM devices simultaneously for 10 days was conducted to explore performance differences between CGM devices and application sites. Our case report was consistent with both hypotheses as clinically meaningful differences were observed between time-matched, same-arm Dexcom G6 versus FreeStyle Libre Pro glucose readings and between time-matched FreeStyle Libre Pro right-arm versus left-arm glucose readings. Glycemic control was not significantly impacted by the three Dexcom G6 application sites.