Clinical Implications of Real-time and Intermittently Scanned Continuous Glucose Monitoring

Two types of continuous glucose monitoring (CGM) systems are now available: real-time CGM (rtCGM) and intermittently scanned (isCGM). Current rtCGM systems automatically transmit a continuous stream of glucose data to the user, provide alerts and active alarms, and transmit glucose data (trend and numerical) in real time to a receiver, smart watch, or smartphone. The current isCGM system provides the same type of glucose data but requires the user to purposely scan the sensor to obtain information, and it does not have alerts and alarms. Both CGM technologies have significant advantages over self-monitoring of blood glucose; however, differences in the features and capabilities of the two approaches must be considered when guiding patient selection of the system that meets their individual needs.