Performance of the FreeStyle Libre Flash glucose monitoring system in patients with type 1 and 2 diabetes mellitus

• Published in: BMJ open diabetes research & care Vol. 5; no. 1; p. e000320
• Main Authors: Fokkert, M J, van Dijk, P R, Edens, M A, Abbes, S, de Jong, D, Slingerland, R J, Bilo, H J G
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group LTD 01.01.2017; BMJ Publishing Group
• Subjects: Accuracy; Clinical medicine; Diabetes; Emerging Technologies and Therapeutics; Glucose; Hypoglycemia; Laboratories; Measurement techniques; Methods; Patients; Sensors; Studies; Usability; Values; Blood Glucose Self-Monitoring; Continuous Glucose Monitoring; Glucose Control; Endocrinology Diabetes
• ISSN: 2052-4897; 2052-4897
• DOI: 10.1136/bmjdrc-2016-000320

ObjectiveTo evaluate the performance of the FreeStyle Libre Flash continuous glucose monitoring (FSL-CGM) system against established central laboratory methods.Research design and methods20 subjects (8 type 1 diabetes mellitus, 12 type 2 diabetes mellitus) were analyzed. FSL-CGM sensor measurements (inserted in arm and abdomen) were compared with capillary blood glucose results analyzed with StatStrip as semigold standard. The glucose response after a standardized oral glucose load was measured by FSL-CGM and capillary samples analyzed by perchloric acid hexokinase (PCA-HK) method, StatStrip and FSL test strip (FSLC), and a commonly used CGM system (iPro2).ResultsFSL-CGM arm sensor readings showed 85.5% of paired readings falling within Clarke Error Grid (ISO 15197:2013) zone A when compared with StatStrip. For FSL-CGM abdomen and FSLC, these percentages were 64% and 98%, respectively. The overall correlation of FSL-CGM in the arm and the StatStrip indicates a performance with lower results with the FSL-CGM in the arm than expected based on the StatStrip in the lower glucose ranges, and higher results than expected in the higher ranges. Following a standardized glucose load, a slower rise in glucose level was observed for FSL-CGM arm as compared with PCA-HK, StatStrip, FSLC, and iPro2 during the first 45–60 min after glucose load ingestion.ConclusionsCertain matters need attention while using the FSL-CGM in daily life including the observed lower values in the lower ranges, and the underestimation of the effect of a meal on glucose response. These effects of such deviations can partly be overcome by optimizing the available user instructions.Trial registration numberTC5348; results.