A new, safe, and practical approach for using trend arrow data from a real-time continuous glucose monitoring system helps adult patients with diabetes to adjust insulin dosing to improve glucose control, according to an article published in the Journal of the Endocrine Society.1
Researchers used the newly approved Dexcom G5 Mobile CGM system (Dexcom G5, Dexcom, Inc., San Diego, California) for nonadjunctive insulin dosing to develop their approach based on a review of 4 previously published methods using trend arrow dosing to adjust insulin doses.1-5 Rather than using a measurement from a static point in time, this device’s trend arrow data allows users to anticipate future glucose levels and proactively adjust their insulin dose accordingly.1
In general, upward trend arrows indicate rising glucose levels — which may require additional insulin — while downward trend arrows indicate falling glucose levels — which may require less insulin or corrective action with carbohydrate intake to prevent hypoglycemia. Using the trend arrow approach does not replace, but rather adds to, standard calculations using the insulin-to-carbohydrate ratio and correction factor to determine insulin doses.
It is important to note that using trend arrow data focuses on adjusting the insulin dose pre-meal and making corrections at least 4 hours post-meal.1 For the 4 hours following a meal, the researchers recommend using the REPLACE-BG study approach to minimize hypo- and hyperglycemia.1,6 The researchers also provide recommendations for adjusting for the trend arrow data on sick days, in elderly and frail adults, when exercising or during physical activity, and environmental factors to consider.
The investigators concluded, “We believe this simplified approach reduces numeracy requirements and the number of calculations, which will help patients improve glucose control and increase glucose time in range without hypoglycemia, while promoting clinical discussion.”
This publication was supported by an unrestricted educational grant from Dexcom, Inc., San Diego, California, the manufacturer of Dexcom G5 CGM.
- Aleppo G, Laffel LM, Ahmann AJ, et al. A practical approach to using trend arrows on the Dexcom G5 CGM system for the management of adults with diabetes [published online November 20, 2017]. J Endocr Soc. doi:10.1210/js.2017-00388
- Buckingham B, Xing D, Weinzimer S, et al; Diabetes Research In Children Network (DirecNet) Study Group. Use of the DirecNet Applied Treatment Algorithm (DATA) for diabetes management with a real-time continuous glucose monitor (the FreeStyle Navigator). Pediatr Diabetes. 2008;9(2):142-147.
- Scheiner G. Practical CGM: Improving Patient Outcomes Through Continuous Glucose Monitoring. 4th ed. Alexandria, VA: American Diabetes Association; 2015.
- Pettus J, Edelman SV. Recommendations for using real-time continuous glucose monitoring (rtCGM) data for insulin adjustments in type 1 diabetes. J Diabetes Sci Technol. 2017;11(1):138-147.
- Klonoff DC, Kerr D. A simplified approach using rate of change arrows to adjust insulin with real-time continuous glucose monitoring. J Diabetes Sci Technol. 2017;11(6):1063-1069.
- Aleppo G, Ruedy KJ, Riddlesworth TD, et al; REPLACE-BG Study Group. REPLACE-BG: a randomized trial comparing continuous glucose monitoring with and without routine blood glucose monitoring in adults with well-controlled type 1 diabetes. Diabetes Care. 2017;40(4):538-545.