Glucose Sensor Accuracy After Subcutaneous Glucagon Injections Near to Sensor Site

Area of Science:

• Endocrinology and Metabolism
• Biomedical Engineering
• Diabetes Technology

Background:

• Integrated hormone delivery and glucose sensing systems are crucial for diabetes management.
• Glucose sensor performance may be compromised by pharmacological interferences, such as glucagon administration.

Purpose of the Study:

• To evaluate the accuracy of continuous glucose monitors (CGM) following subcutaneous (s.c.) administration of low-dose glucagon near the sensor site.
• To compare sensor performance when glucagon is administered proximally versus remotely from the sensor.

Main Methods:

• Twelve adults with type 1 diabetes on insulin pump therapy participated.
• Two continuous glucose monitors (CGM) were worn on the abdomen; one near (CGM_glucagon) and one remote (CGM_control) from s.c. glucagon injections.
• Sensor accuracy was assessed using Yellow Spring Instrument (YSI) measurements and self-monitoring of blood glucose (SMBG), analyzed by MARD and Clarke error grid.

Main Results:

• No significant difference in Median Absolute Relative Difference (MARD) was observed between CGM_glucagon and CGM_control when compared to YSI (15.7% vs. 13.4%, P=0.195) or SMBG (11.0% vs. 6.2%, P=0.148).
• Clarke error grid analysis showed no significant differences in accuracy (Zone A+B: 93.9% vs. 91.1% for YSI, P=0.250; 97.3% vs. 95.0% for SMBG, P=0.375).
• The precision absolute relative deviation between sensors was 13.7%.

Conclusions:

• Subcutaneous administration of low-dose glucagon near a continuous glucose monitor sensor does not significantly affect its accuracy.
• These findings support the feasibility of integrated systems combining glucagon delivery and continuous glucose monitoring without compromising sensor reliability.