Continuous Glucose Monitoring (CGM) Reduces Risks for Hypo- and Hyperglycemia and Glucose Variability in Diabetes | American Diabetes Association
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Continuous Glucose Monitoring (CGM) Reduces Risks for Hypo- and Hyperglycemia and Glucose Variability in Diabetes Recent studies underscore the Recent studies underscore the importance of controlling blood glucose (BG) variability and its two extremes, hypo- and hyperglycemia. However, BG variability and associated risks are not captured by HbA1c, which is slowly-changing and insensitive to rapid BG variation. By contrast, we hypothesized that CGM may enable patients to rapidly recognize and reduce BG extremes and associated risks, and used risk analysis to affirm this hypothesis.
As previously reported, the risk analysis uses Low, High, and combined BG Risk Indices (LBGI, HBGI, and RISK) to measure the likelihood of future hypo-, hyper-, and extreme glycemic excursions. Each index has established low, moderate and high-risk categories; in previous studies subjects in the high-risk LBGI category had [sim]10-fold the rate of severe hypoglycemia of those at low risk.
Risk analysis was applied to a sample data set from 123 subjects with T1DM or insulin-treated T2DM who used the FreeStyle Navigator[reg] Continuous Glucose Monitoring system for 20 days masked to real-time data; then 20 days unmasked, showing real-time BG and alarms.
The study was split into four 10-day time bins for analysis. There were no significant differences within the masked or unmasked phases of the study. There was a highly significant reduction in risk between the masked and unmasked phases for hypoglycemia LBGI (p[lt]0.001), hyperglycemia HBGI (p[lt]0.005), and extreme glycemic excursions RISK (p[lt]0.001). The % subjects in the high risk category for hypoglycemia was reduced more than 3-fold, from 9.8% during the masked phase to 2.9% when unmasked (p[lt]0.001). Similarly, the % subjects at high risk for extreme BGs was reduced 3-fold from 7.9% to 2.5% (p[lt]0.005).
Overall BG variability (SD) was also reduced (p[lt]0.005) and time in target range (3.9-10mM) increased from 55% to 59% (p[lt]0.001). Average BG did not change throughout the study.
Risk analysis reveals treatment effects inaccessible by standard statistical techniques: a marked reduction in risks for hypo- and hyperglycemia and in glycemic variability taking place during the first 10 days of unmasked use of FreeStyle Navigator system, and sustained afterwards. No change occurred after the first 10 days of masked CGM. Therefore, we surmise that the risk reduction was due to real-time data display and alarms in the unmasked phase. BORIS KOVATCHEV, WILLIAM CLARKE, Charlottesville, VA 0086-OR Clinical Therapeutics/New Technology - Glucose Monitoring and Sensing
67th Scientific Sessions (2007)
Clinical Therapeutics/New Technology - Glucose Monitoring and Sensing