Steno Diabetes Center North Denmark, Aalborg University Hospital, Aalborg, Denmark.
Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
J Diabetes Sci Technol. 2020 Nov;14(6):1074-1078. doi: 10.1177/1932296819848721. Epub 2019 May 16.
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.
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.
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.
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.
连续血糖监测（CGM）是一种强大的工具，无论是在临床实践还是临床试验中都值得考虑。然而，由于多种原因，包括生理延迟，CGM 一直受到不准确的批评。本研究旨在调查当前的延迟问题并提出一种简单的后处理程序。
通过时间推移 CGM 测量值并将其与血浆葡萄糖（PG）测量值进行比较，对来自一项最先进临床试验的 472 名受试者的超过 100 万小时的 Dexcom G4 CGM 数据进行了分析。然后，根据真实世界的临床研究终点评估了所得 CGM 测量值。
CGM 的时间偏移-9 分钟是最佳的，并且统计学上显著降低了 1.0%的平均绝对相对差异（MARD）。MARD 的降低导致低血糖和餐后血糖增加的临床研究终点更好。
CGM 的延迟仍然是一个问题。与 PG 相比，本研究中 CGM 的延迟被确定为 9 分钟。通过简单的后处理方法，即对 CGM 测量值进行-9 分钟的时间推移，可以获得统计学上显著更低的 MARD，从而获得更有效的临床研究终点。
