The Impact of Interfering Substances on Continuous Glucose Monitors: Part 2: Marketed CGM Designs, Labeled Interfering Substances, and Design Mitigations

Presented is a series of narrative reviews that summarize published information regarding the effect or potential effect of interfering substances on the accuracy of continuous glucose monitoring (CGM) devices. While drawing together what is currently known regarding this topic, the future direction in this field and clinical implications posed by polypharmacy on CGM performance are considered. This second in a series of review articles introduces the glucose-sensing designs of commercially available continuous glucose monitors (CGMs) and describes those interfering substances currently or historically identified within manufacturer's labeling for a given CGM model. Where known, an overview of the mechanistic effects of labeled interfering substances on the corresponding CGM designs is also described, as are sensor design approaches introduced by leading manufacturers to reduce interference effects. The review also considers: the effect of interferents on market-leading minimally invasive CGMs; design changes made to limit the flux of interfering substances to the sensor's glucose-sensing element; and an appraisal of the minimally invasive implantable Senseonics Eversense system, which employs a unique synthetic glucose-recognition ligand coupled to optical signal generation, which correspondingly gives rise to a unique interference profile.