Comparison of Continuous Glucose Monitoring Accuracy Between Abdominal and Upper Arm Insertion Sites.

The aim was to compare the accuracy of the Dexcom G4 Platinum continuous glucose monitor (CGM) sensor inserted on the upper arm and the abdomen in adults. Fourteen adults with type 1 diabetes wore two CGMs, one placed on the upper arm and one placed on the abdomen. Three in-clinic visits of 5 h with YSI (2300 STAT, Yellow Springs Instrument) measurements as comparator were performed. Each visit was followed by 4 days with seven-point self-monitoring of blood glucose (SMBG) in free-living conditions. Accuracy analyses on the paired CGM-YSI and CGM-SMBG measurements of the two CGM sensors were performed. Using YSI as comparator, the overall Mean Absolute Relative Difference (MARD) for the CGM was 12.3% and CGM was 12.0%. The percentage of the CGM measurements in zone A of Clarke error grid analysis for the CGM was 85.6% and CGM was 86.0%. The hypoglycemia sensitivity for the CGM and CGM was 69.3%. Using SMBG as comparator, the overall MARD for the CGM was 12.5% and CGM was 12.0%. The percentage of the CGM measurements in zone A for the CGM was 84.1% and the CGM was 85.0%. The hypoglycemia sensitivity for the CGM was 60.0% and the CGM was 71.1%. All the -values from the comparisons between the accuracy of CGM and CGM were >0.05. The accuracy of a Dexcom G4 Platinum CGM sensor placed on the upper arm was not different from the accuracy of the sensor placed on the abdomen in adults with type 1 diabetes.