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Endocrine Society issues guidance for CGM trend arrow data

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November 20, 2017

Researchers with the Endocrine Society developed two guidelines for pediatric and adult patients using the Dexcom G5 mobile continuous glucose monitor system that include detailed recommendations on insulin dosing employing trend arrow data.

The new guidelines, based on a review of four previously published methods, include an approach to adjusting insulin doses based on both trend arrows and an individual patient’s insulin sensitivity.

The Endocrine Society recommends CGM as the gold standard for managing type 1 diabetes. In December 2016, the FDA approved the Dexcom G5 mobile CGM system for nonadjunctive insulin dosing. Although patients can now dose insulin without confirmatory finger-stick glucose monitoring in most situations, evidence is sparse for how individuals should interpret CGM trend arrow data, the researchers noted.

“Notably, there are four previously published methods for using trend arrow data to adjust insulin doses,” Grazia Aleppo, MD, of the division of endocrinology, metabolism and molecular medicine at Northwestern University Feinberg School of Medicine, and colleagues wrote. “However, each method has various limitations in its complexity, utility and applicability. Our approach focuses on the Dexcom G5 system — the first Food and Drug Administration-approved system for nonadjunctive insulin dosing and the system that we have the most clinical experience using in this manner to date.”

In the recommendations, researchers developed two tables — one for adults and one for children and adolescents — to help patients calculate how CGM trend arrows should influence their insulin dose decisions. The method provides suggested dose adjustments in insulin units to simplify calculations for CGM users.

“This new tool will help individuals maintain better control of their glucose levels while minimizing dangerous glucose fluctuations,” Aleppo said in a press release.

Previous approaches to using the trend arrows required complex calculations, such as knowing precise amounts of food consumed during a meal, then adding a percentage of the dose to account for the rate of change arrows. Other approaches included adding predetermined values to glucose levels and were of limited use to patients using insulin pens.

The Endocrine Society sought to refine existing approaches to address these challenges while accounting for both children and adults with diabetes, displaying a wide range of insulin sensitivities, according to researchers.

“This new method will make it simpler for health care providers to help their patients with diabetes to adjust their insulin doses based upon the trend arrows. In turn, persons with diabetes should receive greater benefit from the CGM and the trend data collected by the device,” Lori M. Laffel, MD, MPH, of the pediatric, adolescent and young adults program at Joslin Diabetes Center and Harvard Medical School, said in the release. “It will help individuals maintain their glucose levels within target range, rather than experience substantial variation between highs and lows.”

The recommendations for adults and children were published online in the Journal of the Endocrine Society.by Regina Schaffer

Disclosures: The work was supported by an unrestricted grant to the Endocrine Society from Dexcom.