Evaluating the Clinical Accuracy of GlucoMen®Day: A Novel Microdialysis-Based Continuous Glucose Monitor

Abstract

Background: The objective of this work was to determine the clinical accuracy of GlucoMen®Day, a new microdialysis-based continuous glucose monitoring system (CGMS) from A. Menarini Diagnostics (Florence, Italy). Accuracy evaluation was performed using continuous glucose-error grid analysis (CG-EGA), as recommended by the Performance Metrics for Continuous Interstitial Glucose Monitoring; Approved Guideline (POCT05-A). Methods: Two independent clinical trials were carried out on patients with types 1 and 2 diabetes mellitus, the glycemic levels of whom were monitored in an in-home setting for 100-hour periods. A new multiparametric algorithm was developed and used to compensate in real-time the GlucoMen®Day signal. The time lag between continuous glucose monitoring (CGM) and reference data was first estimated using the Poincaré plot method. The entire set of CGM/reference data pairs was then evaluated following the CG-EGA criteria, which allowed an estimation of the combined point and rate accuracy stratified by glycemic ranges. Results: With an estimated time lag of 11 minutes, the linear regression analysis of the CGM/reference glucose values yielded r = 0.92. The mean absolute error (MAE) was 11.4 mg/dl. The calculated mean absolute rate deviation (MARD) was 0.63 mg/dl/min. The data points falling within the A+B zones of CG-EGA were 100% in hypoglycemia, 95.7% in euglycemia, and 95.2% in hyperglycemia. Conclusions: The GlucoMen®Day system provided reliable, real-time measurement of subcutaneous glucose levels in patients with diabetes for up to 100 hours. The device showed the ability to follow rapid glycemic excursions and detect severe hypoglycemic events accurately. Its accuracy parameters fitted the criteria of the state-of-the-art consensus guideline for CGMS, with highly consistent results from two independent studies.

Performance Evaluation of Three Continuous Glucose Monitoring Systems: Comparison of Six Sensors Per Subject in Parallel

“…In 2008, the Clinical and Laboratory Standards Institute published POCT05-A, which provides recommendations for study design and parameters of interest in the performance evaluation of CGM systems. 1 Multiple studies investigating CGM systems were published over the years; [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] only one claimed to use procedures recommended in POCT05-A. 13 A comparison of these studies, however, is difficult due to variations in subject groups 11 and study design, including use of different devices for calibration of CGM systems and for reference measurements, either overall or for different study phases.…”

“…1 Multiple studies investigating CGM systems were published over the years; [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] only one claimed to use procedures recommended in POCT05-A. 13 A comparison of these studies, however, is difficult due to variations in subject groups 11 and study design, including use of different devices for calibration of CGM systems and for reference measurements, either overall or for different study phases. [2][3][4][6][7][8][9][10]12,13,16,17 Given that comparability of different CGM systems is heavily influenced by these factors, it is thus improved when the different CGM systems are worn simultaneously by the same subjects under identical conditions (e.g., in head-to-head comparisons).…”

“…13 A comparison of these studies, however, is difficult due to variations in subject groups 11 and study design, including use of different devices for calibration of CGM systems and for reference measurements, either overall or for different study phases. [2][3][4][6][7][8][9][10]12,13,16,17 Given that comparability of different CGM systems is heavily influenced by these factors, it is thus improved when the different CGM systems are worn simultaneously by the same subjects under identical conditions (e.g., in head-to-head comparisons). There are studies in which different CGM systems were compared under such conditions, 2,7,12 but in these cases, only one sensor per CGM system was worn by the subjects.…”

A Subcutaneous Biochip for Remote Monitoring of Human Metabolism: Packaging and Biocompatibility Assessment

“…ONTINUOUS monitoring of humans is already in the market for glucose [1] and lactate [2], thanks to the electrochemical sensing, and prototypes of fully implantable Manuscript received May 11, 2014; accepted July 7, 2014. Date of publication July 18, 2014; date of current version November 7, 2014.…”

“…A battery-less system for the remote powering of the device [13], and an integrated circuit capable of generating on-board voltage ramps [14], ensure the device autonomy; finally, to promote biostability and biocompatibility, we added a double protection for electrodes and electronic components: enzymes and CNTs were entrapped in a chitosan (CHT) matrix and then sealed behind a porous polycarbonate membrane. Chitosan is a natural polysaccharide with unique biological properties including non-toxicity, physiological inertness, affinity to proteins, hemostatic fungistatic and antitumoral properties, which already found employ in biosensors [15], while polycarbonate membranes are commonly employed as microdialysis filters in commercial biosensors [1]. Corrosion of electronic components and leaking of potentially hazardous substances in the body was prevented by a conformal coating of Parylene C, an inert and biocompatible polymer with widespread industrial use as diffusion barrier.…”