Introduction to CGM Interference Profiles

Continuous glucose monitoring (CGM) systems are prone to interference from various sources, primarily driven by the sensor's transduction method. This comparison aims to provide an overview of the interference profiles of different CGM systems, highlighting the key differences between electrochemical and optical transduction methods.

Electrochemical CGM Systems

Electrochemical CGM systems, utilized by manufacturers such as Dexcom, Abbott, and Medtronic, are susceptible to interference from certain drugs that oxidize at the electrode, resulting in false hyperglycemia readings. The main interferents for these systems include:

• Acetaminophen: High doses of acetaminophen can cause interference in Dexcom G6/G7 and Libre sensors, although the use of permselective membranes has mitigated this issue [1].
• Ascorbic Acid (Vitamin C): Ascorbic acid is a major interferent for Abbott FreeStyle Libre sensors, causing false highs at doses exceeding 500mg/day [2].
• Hydroxyurea: Hydroxyurea is a critical contraindication for Dexcom and Medtronic CGM systems, as it can cause massive false highs [3].

Optical CGM Systems (Eversense)

Optical CGM systems, such as the Eversense sensor, use fluorescence quenching and are immune to electrochemical noise from substances like Tylenol and Vitamin C. However, they have unique vulnerabilities:

• Tetracyclines: Tetracyclines can cause false lows due to fluorescence quenching [4].
• Mannitol: Mannitol can cause false highs due to competitive binding [5].

Oxygen Interference

Oxygen levels can also interfere with CGM readings. Abbott's \