Continuous glucose monitoring metrics (Mean Glucose, time above range and time in range) are superior to glycated haemoglobin for assessment of therapeutic efficacy. Issue 2 (1st December 2022)

• Record Type: Journal Article
• Authors: Rodbard, David
• Is Part Of: Diabetes, obesity & metabolism. Volume 25:Issue 2(2023)
• Page Start: 596
• Page End: 601
• Publication Date: 2022-12-01
• Subjects: Mean Glucose -- %TAR -- %TIR -- HbA1c -- efficacy -- quality of glycemic control -- type 1 diabetes (T1D) -- type 2 diabetes (T2D) -- glycemic variability; Diabetes -- Periodicals; Obesity -- Periodicals; Metabolism -- Disorders -- Periodicals; Clinical pharmacology -- Periodicals; 616.462
• DOI: 10.1111/dom.14906
• Languages: English
• ISSNs: 1462-8902

Abstract

Abstract: Aim: To evaluate continuous glucose monitoring (CGM) metrics for use as alternatives to glycated haemoglobin (HbA1c ) to evaluate therapeutic efficacy. Methods: We re‐analysed correlations among CGM metrics from studies involving 545 people with type 1 diabetes (T1D), 5910 people with type 2 diabetes (T2D) and 98 people with T1D during pregnancy and the postpartum period. Results: Three CGM metrics, interstitial fluid Mean Glucose level, proportion of time above range ( %TAR ) and proportion of time in range ( %TIR ), were correlated with HbA1c and provided metrics that can be used to evaluate therapeutic efficacy. Mean Glucose showed the highest correlation with %TAR ( r = 0.98 in T1D, 0.97 in T2D) but weaker correlations with %TIR ( r = −0.92 in T1D, −0.83 in T2D) or with HbA1c ( r = 0.78 in T1D). %TAR and %TIR were highly correlated ( r = −0.96 in T1D, −0.91 in T2D). After 6 months of use of real‐time CGM by people with T1D, changes in Mean Glucose level were more highly correlated with changes in %TAR ( r = 0.95) than with changes in %TIR ( r = −0.85) or with changes in HbA1c level ( r = 0.52). These metrics can be combined with metrics of hypoglycaemia and/or glycaemic variability to provide a more comprehensive assessment of overall quality of glycaemic control. Conclusion: The CGM metrics %TAR and %TIR show much higher correlations with Mean Glucose than with HbA1c and provide sensitive indicators of efficacy. Mean glucose may be the best metric and shows consistently higher correlations with %TAR than with %TIR .