Evaluation of the Accuracy of FreeStyle Libre 2 for Glucose Monitoring in White New Zealand Rabbits

ABSTRACT Background Studies are currently being conducted on rabbits requiring serial glucose monitoring. The FreeStyle Libre 2 (FSL2), a serial glucose monitoring device, has been validated in humans, dogs and cats, but not in rabbits. Objectives This study aimed to evaluate the accuracy of the FSL2 in rabbits. Methods Six healthy rabbits were used in this study. Interstitial glucose (IG) was measured using the FSL2, and blood glucose (BG) was measured using a portable blood glucose meter (PBGM); their results were compared with those from a clinical chemistry analyser. For the first 3 h, IG and BG were measured at 1‐h intervals. Subsequently, they were measured every 8 h over a 48‐h period. Regular insulin 0.2 U/kg was then administered to the rabbits, and IG and BG were measured every 15 min over a 90‐min period. Results Before insulin treatment, no measurements fell within the hypoglycaemic range (BG < 100 mg/dL). In the euglycaemic range (BG ≥ 100 mg/dL), the PBGM and FSL2 showed 85.7% and 23.8% accuracies, respectively. After insulin treatment, the PBGM showed 95.5% and 81.3% accuracies in the hypoglycaemic and euglycaemic ranges, respectively. The FSL2 showed 68.1% and 37.5% accuracies in the hypoglycaemic and euglycaemic ranges, respectively. Parkes consensus error grid analysis showed that the PBGM and FSL2 had 100% agreement for Zones A (no effect on clinical action) and B (altered clinical action unlikely to affect outcome) in rabbits with and without insulin treatment. Conclusions There was limited agreement between the FSL2 and reference standard BG measurements. However, the FSL2 allows clinically acceptable identification of hypoglycaemic states in rabbits.