Severe Hyperglycemia due to Calibration Misuse in an Eversense-365 Implantable Continuous Glucose Monitoring System
Year: 2026
Type: article
Study design: Case Report
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.
Source: AACE Endocrinology and Diabetes
Author: Jennifer Moeller
Language: English
Subfield: Endocrinology, Diabetes and Metabolism
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
OpenAlex ID: W7170162822