Recommendations for Using Real-Time Continuous Glucose Monitoring (rtCGM) Data for Insulin Adjustments in Type 1 Diabetes

The clinical benefits of real-time continuous glucose monitoring (rtCGM) use have been well demonstrated in individuals treated with continuous subcutaneous insulin infusion (CSII) and multiple daily injections (MDI) in large clinical trials. However, recommendations for patient use of real-time CGM in everyday life situations are lacking. This article provides guidance to clinicians and patients with type 1 diabetes (T1D) in effective use of rtCGM data, including glucose rate of change (ROC) arrows for insulin dosing adjustments and other treatment decisions. The recommendations presented here are based on our own clinical experiences as endocrinologists, our personal experiences living with T1D using rtCGM, and findings from a recent survey of T1D patients who have successfully used real-time continuous glucose monitoring in their type 1 diabetes self-management. It is important that both clinicians and people with diabetes understand the utility and limitations of rtCGM. Maintaining a collaborative clinician-user relationship remains an important factor in safe, successful rtCGM use.

The clinical benefits of real-time CGM use have been well demonstrated in both CSII- and MDI-treated T1D individuals; however, few studies have specifically looked at how individuals utilize rtCGM data. Although CGM management algorithms were established for subjects in clinical trials, recommendations for patient use of rtCGM in everyday life situations are lacking.

The purpose of this article is to provide guidance to clinicians and patients with type 1 diabetes (T1D) in effective use of rtCGM data, including glucose rate of change (ROC) arrows for insulin dosing adjustments and other treatment decisions. The recommendations presented here are based both on our own clinical experiences as endocrinologists and our personal experiences living with T1D using real-time CGM. Our recommendations are also based on findings from a recent survey we conducted to explore how 222 individuals with T1D used real-time continuous glucose monitoring successfully, defined as having a good A1C and minimal hypoglycemia, in their everyday self-management. Findings from the survey will be discussed throughout the article. It is important to note that the recommendations presented here are specific to the Dexcom Platinum G4 and G5 Mobile (Dexcom, Inc., San Diego, Calif., USA), both of which use the Software 505 algorithm. However, these recommendations can be adapted to other types of Dexcom real-time continuous glucose monitoring (rtCGM) systems.

Pettus J, et al. J Diabetes Sci Technol. 2017;11(1):138-47.