CGM Alarm Fatigue in Youth?

Marcus A. Banks

June 26, 2023

Teenagers with diabetes who use a continuous glucose monitor (CGM) employ a wide variety of alarm settings to alert them when their blood sugar may be too high or too low. But sometimes those thresholds generate too many alarms — which in turn might lead patients to ignore the devices, according to a study presented at the 2023 annual meeting of the Endocrine Society.

Victoria Ochs, BS

"These alarms alert people with diabetes and their caregivers of pending glycemic changes. However, little work has been done studying CGM alarm settings in pediatric clinical populations," said Victoria Ochs, BS, a medical student at the Indiana University School of Medicine, Indianapolis, who helped conduct the study.

Ochs and colleagues analyzed 2 weeks of real-time CGM alarm settings from 150 children with diabetes treated at Indiana. Their average age was 14 years; 47% were female, 89% of were White, 9.5% were Black, and 1.5% were Asian. Approximately half the patients used insulin pumps (51%) in addition to the monitoring devices.  

For both alarms that indicated blood sugar was too low or too high, settings among the children often varied widely from thresholds recommended by the University of Colorado’s Barbara Davis Center for Diabetes, Aurora. Those thresholds are 70 mg/dL of glucose for low and 180 mg/dL for high glucose. At Indiana, the median alert level for low was set to 74 mg/dL (range: 60-100), while the median for high was 242 mg/dL (range: 120-400). 

"If we have it set at 100, what exactly is the purpose of that? Is it just to make you more anxious that you’re going to drop low at some point?" asked Cari Berget, MPH, RN, CDE, who specializes in pediatric diabetes at the University of Colorado, speaking of the low blood sugar alarm. Setting this alarm at 70 md/dL instead could lead to concrete action when it does go off — such as consuming carbohydrates to boost blood sugar, she said. 

"Alarms should result in action most of the time," said Berget, who is also the associate director of Colorado’s PANTHER program, which established the alarm thresholds used in the Indiana study. Alarm setting is not one-size-fits-all, Berget noted: Some people might want 70 mg/dL to warn of low blood sugar, whereas others prefer 75 or 80 mg/dL. 

As for alerts about hyperglycemia, Berget said patients often exceed the high range of 180 mg/dL immediately after a meal. Ideally these sugars will subside on their own within 3 hours, a process aided by insulin shots or pumps. Setting a threshold for high blood sugar too low, such as 120 mg/dL, could result in ceaseless alarms even if the person is not at risk for harm.

"If you receive an alarm and there’s no action for you to take, then we need to change how we’re setting these alarms," Berget said. She advised parents and children to be thoughtful about setting their CGM alarm thresholds to be most useful to them.

Ochs said in some cases families have CGM devices shipped directly to their home and never consult with anyone about optimal alarm settings.

"It would be useful to talk to families about what baseline information they had," Ochs told Medscape Medical News. "It would be nice to talk to diabetes educators, and I think it would be nice to talk to physicians."

Ochs reports no relevant financial relationships. Berget has consulted for Dexcom and Insulet.

2023 Endocrine Society. Presented June 15, 2023.

Marcus A. Banks, MA, is a journalist based in New York City who covers health news with a focus on new cancer research. His work appears in Medscape, Cancer Today, The Scientist, Gastroenterology & Endoscopy News, Slate, TCTMD, and Spectrum.

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