Simple Post-Processing of Continuous Glucose Monitoring Measurements Improves Endpoints in Clinical Trials

• Published in: Journal of diabetes science and technology 2020-11, Vol.14 (6), p.1074-1078
• Main Authors: Jensen, Morten Hasselstrøm, Dethlefsen, Claus, Hejlesen, Ole, Vestergaard, Peter
• Format: Article
• Language: English
• Subjects: Original
• ISSN: 1932-2968; 1932-2968; 1932-3107
• DOI: 10.1177/1932296819848721

Background: Continuous glucose monitoring (CGM) is a powerful tool to be considered both in clinical practice and clinical trials. However, CGM has been criticized for being inaccurate for many reasons including a physiological delay. This study sought to investigate the current delay issue and propose a simple post-processing procedure. Method: More than a million hours of the Dexcom G4 CGM from 472 subjects investigated in a state-of-the-art clinical trial were analyzed by time shifting the CGM measurements and comparing them to plasma glucose (PG) measurements. The resultant CGM measurements were then assessed in relation to real-world clinical research endpoints. Results: A CGM time shift of −9 minutes was optimal and reduced mean absolute relative difference (MARD) statistically significantly with 1.0% point. The MARD reduction resulted in better clinical research endpoints of hypoglycemia and postprandial glucose increments. Conclusions: The delay in CGM is still an issue. The delay in this study was identified to be 9 minutes compared to PG. With a simple post-processing approach of time shifting the CGM measurements with −9 minutes, it was possible to obtain a statistically significantly lower MARD and subsequently obtain clinical research endpoints of improved validity.