Coefficient of Variation(CV)
Definition
A standardized measure of glucose variability calculated as the standard deviation of glucose values divided by the mean glucose, multiplied by 100, expressed as a percentage. A CV below 36% is the internationally recommended target indicating stable glucose control, while values above 36% signal problematic glucose variability that increases the risk of both hyperglycemia and hypoglycemia. CV is considered more reliable than standard deviation alone because it adjusts for differences in mean glucose levels between individuals.
Why “Coefficient of Variation” Matters for Glucose Monitoring
Understanding coefficient of variation is essential for anyone using or evaluating a continuous glucose monitor. This concept directly affects how CGM devices are designed, how glucose data is interpreted, and how clinical decisions about blood sugar management are made. CGM metrics transform thousands of raw glucose readings into actionable numbers that clinicians use to assess glucose control, adjust medications, and set treatment goals.
This term applies broadly across all continuous glucose monitors and is foundational knowledge for interpreting CGM data, whether you are managing diabetes or using a sensor for metabolic wellness.
Related Terms
The magnitude and frequency of blood glucose fluctuations over a defined period.
The percentage of time a person's glucose level remains within a defined target range, typically 70 to 180 mg/dL for most people with diabetes.
A standardized one-page glucose report recommended by the International Diabetes Center that summarizes 14 days of CGM data into a visual profile showing median glucose, interquartile range (25th to 75th percentile), and 10th to 90th percentile bands across a 24-hour period.
Mean Absolute Relative Difference, the gold standard metric used to evaluate CGM sensor accuracy.