Impact of Body Composition on the Accuracy of a Medtronic Guardian Continuous Glucose Monitoring System

Continuous glucose monitoring (CGM) systems are used in therapeutic decisions for diabetes management, however, the impact of body composition on CGM accuracy is not known. Body composition variables (body mass index [BMI], midarm circumference, percentage fat, and impedance) were collected in an observational study designed to determine the accuracy of an investigational Medtronic Guardian™ sensor 3. Seven days of sensor glucose data were analyzed from 112 participants >7 years of age with mean BMI Z score 0.48 (<18 years) and BMI 26.7 kg/m2 (≥18 years). The outcome was the absolute relative difference between the sensor and blood glucose readings. Data were analyzed using generalized estimating equations to account for correlation between repeated measures. No statistically significant associations between measures of body composition and device accuracy were found. Body composition does not have a meaningful impact on the accuracy of CGM systems.