Variation of Interstitial Glucose Measurements Assessed by Continuous Glucose Monitors in Healthy, Nondiabetic Individuals

OBJECTIVE To characterize glucose levels during daily living using continuous glucose monitors (CGMs) in nondiabetic individuals. RESEARCH DESIGN AND METHODS Seventy-four healthy children, adolescents, and adults aged 9-65 years with normal glucose tolerance used a blinded CGM device for 3 to 7 days. RESULTS Sensor glucose concentrations were 71-120 mg/dl for 91% of the day. Sensor values were 140 mg/dl for only 0.2% and 0.4% of the day, respectively. Sensor glucose concentrations were slightly higher in children than adults (P = 0.009) and were slightly lower during the night than day (95 vs. 99 mg/dl, P < 0.001). CONCLUSIONS Glucose values 140 mg/dl, measured with CGM, are uncommon in healthy, nondiabetic individuals. CGM may be useful to evaluate glucose tolerance in nondiabetic individuals over time. Furthermore, these data provide a basis for comparison for studies that use CGM to assess glucose control in subjects with diabetes.