Improved Quality of Glycemic Control and Reduced Glycemic Variability with Use of Continuous Glucose Monitoring

OBJECTIVE: We evaluated effects of unmasking of continuous display of continuous glucose monitoring (CGM) on quality of glycemic control and glycemic variability. METHODS: We reanalyzed CGM data from 85 patients using a 7-day glucose sensor. Glucose values were "masked" during the first week but "unmasked" during the next 2 weeks. We evaluated 48 criteria for quality of glycemic control, including mean glucose, SD, percentage of values within-, above- or below- specified ranges, Schlichtkrull's M(100) index, mean amplitude of glycemic excursion (MAGE), mean of daily differences (MODD), the J index, "Index of Glycemic Control" (IGC), Hyperglycemia Index, Hypoglycemia Index, High Blood Glucose Index (HBGI), Low Blood Glucose Index (LBGI), average daily risk range (ADRR), GRADE scores, and CONGA(n). We calculated SD values between daily means, between days-within time points, within days, between time points (for the average glucose profile for several days), and within series for time segments of arbitrary length. RESULTS: Unmasking CGM displays resulted in rapid, highly statistically significant improvement in 29 indices, including percentage within, percentage above, and percentage below target range, mean glucose, SD, SD of daily means, MODD, M(100), IGC, GRADE, HBGI, and J index. Both hyperglycemia and hypoglycemia improved during the first week after unmasking; further improvement in hypoglycemia was seen during the following week. Results obtained using multiple criteria were consistent and highly correlated. CONCLUSIONS: Continuous access to display of CGM sensors dramatically improved 29 indices of glycemic control and glycemic variability.