Severe Hyperglycemia due to Calibration Misuse in an Eversense-365 Implantable Continuous Glucose Monitoring System
- 1Division of Diabetes, Endocrinology and Metabolism, Department of Internal Medicine, University of Nebraska Medical Center, Nebraska Medicine, Omaha, Nebraska
Abstract
Background: Continuous glucose monitoring (CGM) systems have transformed diabetes management by improving glycemic outcomes and providing real-time glucose data. Accuracy is commonly assessed by using metrics such as mean absolute relative difference. Implantable CGM systems, including Eversense-365, have demonstrated high accuracy and safety when used in accordance with recommended protocols.
Objective: To describe a case of clinically significant CGM inaccuracy resulting from improper user calibration and to highlight associated safety implications.
Case Report: An adult with a 24-year history of type 1 diabetes complicated by microvascular and macrovascular disease, hypoglycemia unawareness, and mild cognitive impairment was using an implantable CGM system. Initially, sensor readings closely matched capillary glucose values when appropriate fingerstick calibration techniques were followed. However, the patient subsequently used CGM-derived glucose values in place of capillary measurements for calibration. This practice led to progressively inaccurate sensor readings, yielding falsely reassuring glucose values and delaying recognition of clinically significant hyperglycemia.
Discussion: This case highlights a critical safety consideration in implantable CGM systems that rely on user-dependent calibration. Even with otherwise high-performing technology, improper calibration practices can significantly compromise accuracy. As CGM systems become increasingly integrated into automated insulin delivery platforms, user-related factors may introduce risk if proper technique is not consistently followed.
Conclusion: Improper calibration of implantable CGM systems can lead to clinically significant inaccuracies and delayed recognition of hyperglycemia. Reinforcing patient education, adhering to recommended calibration protocols, and selecting patients thoughtfully are essential to ensure the safe and effective use of these devices.
Related
- The hidden pause: Filtering of true prolonged asystole in implantable loop recorder monitoring platform by artificial intelligence.
- Increase in Reimbursement Does Not Necessarily Place a Financial Burden on Patients ― Background Behind the Reimbursement Revision for Remote Monitoring of Cardiac Implantable Electronic Devices in Japan ―
- Changes in Remote Monitoring for Patients With Cardiac Implantable Electronic Devices After a Reimbursement Revision ― An Interrupted Time-Series Analysis ―
- Use of Implantable Loop Recorders: Incidence, Indications for Use, and Pre-implant Rhythm Monitoring Across U.S. Health Systems from 2020-2025
- Temporal drift, calibration monitoring, and adaptive updating of an IVIG resistance prediction model in Kawasaki disease: a multicenter pediatric cohort study
BibTeX
@article{moeller2026severe,
title = {{Severe Hyperglycemia due to Calibration Misuse in an Eversense-365 Implantable Continuous Glucose Monitoring System}},
author = {Jennifer Moeller},
journal = {AACE Endocrinology and Diabetes},
year = {2026},
month = jul,
doi = {10.1016/j.aed.2026.07.007},
url = {https://doi.org/10.1016/j.aed.2026.07.007},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Severe Hyperglycemia due to Calibration Misuse in an Eversense-365 Implantable Continuous Glucose Monitoring System
AU - Jennifer Moeller
PY - 2026
DA - 2026/07/23
JO - AACE Endocrinology and Diabetes
DO - 10.1016/j.aed.2026.07.007
UR - https://doi.org/10.1016/j.aed.2026.07.007
AB - Background: Continuous glucose monitoring (CGM) systems have transformed diabetes management by improving glycemic outcomes and providing real-time glucose data. Accuracy is commonly assessed by using metrics such as mean absolute relative difference. Implantable CGM systems, including Eversense-365, have demonstrated high accuracy and safety when used in accordance with recommended protocols. Objective: To describe a case of clinically significant CGM inaccuracy resulting from improper user calibration and to highlight associated safety implications. Case Report: An adult with a 24-year history of type 1 diabetes complicated by microvascular and macrovascular disease, hypoglycemia unawareness, and mild cognitive impairment was using an implantable CGM system. Initially, sensor readings closely matched capillary glucose values when appropriate fingerstick calibration techniques were followed. However, the patient subsequently used CGM-derived glucose values in place of capillary measurements for calibration. This practice led to progressively inaccurate sensor readings, yielding falsely reassuring glucose values and delaying recognition of clinically significant hyperglycemia. Discussion: This case highlights a critical safety consideration in implantable CGM systems that rely on user-dependent calibration. Even with otherwise high-performing technology, improper calibration practices can significantly compromise accuracy. As CGM systems become increasingly integrated into automated insulin delivery platforms, user-related factors may introduce risk if proper technique is not consistently followed. Conclusion: Improper calibration of implantable CGM systems can lead to clinically significant inaccuracies and delayed recognition of hyperglycemia. Reinforcing patient education, adhering to recommended calibration protocols, and selecting patients thoughtfully are essential to ensure the safe and effective use of these devices.
SN - 3050-9157
ER -