Making sense of glucose metrics in diabetes: linkage between postprandial glucose (PPG), time in range (TIR) & hemoglobin A1c (A1C)

Postgrad Med. 2021 Apr;133(3):253-264. doi: 10.1080/00325481.2020.1851946. Epub 2020 Dec 14.

Abstract

While A1C is the standard diagnostic test for evaluating long-term glucose management, additional glucose data, either from fingerstick blood glucose testing, or more recently, continuous glucose monitoring (CGM), is necessary for safe and effective management of diabetes, especially for individuals treated with insulin. CGM technology and retrospective pattern-based management using various CGM reports have the potential to improve glycemic management beyond what is possible with fingerstick blood glucose monitoring. CGM software can provide valuable retrospective data on Time-in-Ranges (above, below, within) metrics, the Ambulatory Glucose Profile (AGP), overlay reports, and daily views for persons with diabetes and their healthcare providers. This data can aid in glycemic pattern identification and evaluation of the impact of lifestyle factors on these patterns. Time-in-Ranges data provide an easy-to-define metric that can facilitate goal setting discussions between clinicians and persons with diabetes to improve glycemic management and can empower persons with diabetes in self-management between clinic consultation visits. Here we discuss multiple real-life scenarios from a primary care clinic for the application of CGM in persons with diabetes. Optimizing the use of the reports generated by CGM software, with attention to time in range, time below range, and postprandial glucose-induced time above range, can improve the safety and efficacy of ongoing glucose management.

Keywords: AGP; CGM; Diabetes; glycemic management; time in range.

MeSH terms

  • Blood Glucose / metabolism*
  • Blood Glucose Self-Monitoring
  • Diabetes Mellitus / blood*
  • Glycated Hemoglobin / analysis*
  • Humans
  • Monitoring, Ambulatory / methods*
  • Postprandial Period / physiology*
  • Primary Health Care / organization & administration*

Substances

  • Blood Glucose
  • Glycated Hemoglobin A