We’re Saying the Same Thing But Using Different Words: CGM Version

Here we go again! I’m continuing my series on bringing together “layman’s” terms and medical jargon into one neat package. This time with a focus on continuous glucose monitor devices! One thing to note, when discussing CGMs, we no longer use the term “blood sugars,” instead we use “glucose levels” or “sugar levels.” Find out why in my first bullet point below!

Continuous glucose monitor terms

Continuous glucose monitor (CGM)*: A diabetes device that continuously measures the glucose levels in your interstitial fluid. This is different than a glucometer which measures the level of glucose in your bloodstream. Other descriptions: glucose monitor, continuous monitor, “measures my glucose 24-7,” also may be referred to by CGM brand names: Libre, Eversense, Dexcom, Medtronic. *Flash glucose systems, which require you to scan to see your glucose levels or trends, are functionally different than CGMs. However, they are usually referred to as CGMs.

Interstitial fluid: The fluid in between the cells of your body. Glucose typically shifts from the bloodstream, into the interstitial fluid, and eventually (with the aid of insulin) into the cells of your body.

Sensor: A tiny wire that sits under your skin in your interstitial fluid to measure your glucose levels. Other descriptions: sensor wire, sensor patch.

Inserter: A device used to insert the sensor.

Transmitter: A device that sits on top of the sensor and sends glucose levels from the sensor to a receiver. The transmitter may come attached to the sensor already or as a separate piece. Other descriptions:  transmitter device.

Receiver: A device that receives signals from the transmitter. This is the device where you see your glucose levels, trend lines, and/or trend arrows. Receivers may be anything from a smartwatch to a smartphone or an insulin pump. It can also be a receiver that comes with your specific system. Other descriptions: reader, reader device, receiver, scanner.

Trend arrows: Refer to the arrows that are found next to the current glucose level on the receiver screen. These arrows can be pointing upwards, downwards, or horizontally and indicate which direction your glucose level is heading. Other descriptions: rise rates, fall rates, glucose trends, trends, falling, rising.

Alerts/alarms: Signals your CGM system gives you (either by sound or vibration) which lets you know your CGM system or glucose levels need your attention. Examples: a glucose level that’s too low, a lost signal between your transmitter and receiver, etc. Other descriptions: warning, signal.

Target Range: The upper and lower thresholds for which all glucose levels in-between are considered to be healthy. The most common target range used is 70-180 mg/dl, but this varies based on personalized factors like health and age. Other descriptions: target glucose levels, healthy range, safe range.

Time-in-range (TIR): The amount of time your glucose levels spend in the target range. A standard goal is to have 70% of your blood sugars in the target range, but this varies based on personalized factors like health and age. Other descriptions: percent in range.

Glycemic management indicator (GMI)*: An estimation of where your next A1c level may be based on the average glucose levels measured from your CGM system. It is reported as a percentage, similar to your A1c. Other descriptions: average glucose, glucose trends, estimated A1c. *Many may refer to GMI as an A1c, but your A1c may be different based on your red blood cell health and regeneration patterns.

Coefficient of variation (CV): An indicator of your glucose variability, or how much and how often your blood sugars are rising and falling. Usually reported as a percentage, a lower percentage (meaning less variability) is the goal! Other descriptions: variability, glucose variability, rise and fall, liable, liability. Standard deviation (SD) may be used instead of CV to help determine the variability and the other descriptions above may be used to describe SD.