Accuracy of a flash glucose monitoring system in cats and determination of the time lag between blood glucose and interstitial glucose concentrations

Abstract

Background: The FreeStyle Libre (Abbott Laboratories) is a flash glucose monitoring system (FGMS) that measures interstitial glucose concentration (IG). The system is factory-calibrated, easy to use, inexpensive, and could be useful for monitoring diabetic cats.Objectives: To evaluate the analytical and clinical accuracy of the FGMS in cats and establish the lag-time between IG and blood glucose concentration (BG).Animals: Twenty client-owned diabetic cats and 7 purpose-bred healthy cats.Methods: Prospective study. Blood glucose concentration was measured using a portable glucose meter validated for use in cats that served as a reference method for IG, as measured by FGMS. In diabetic cats, data were collected for sensor wearing time with different methods of application and accuracy across glycemic ranges. Accuracy was determined by fulfillment of ISO15197:2013 criteria. In healthy cats, lag-time between IG and BG was established after IV administration of exogenous glucose.Results: Good agreement between IG and BG was obtained (r = .93). Analytical accuracy was not achieved, whereas clinical accuracy was demonstrated with 100% of the results in zones A + B of the Parkes consensus error grid analysis. In the immediate 30 minutes after an IV bolus of glucose, when BG was increasing rapidly (approximately 2%/min), IG increased slowly, resulting in a difference of as much as 579 mg/ dL, and no positive correlation between BG and IG was found.Conclusions and Clinical Importance: The FGMS did not fulfill ISO requirements but is sufficiently accurate for glucose monitoring in cats, while considering the lag between IG and BG during periods of rapid changes in BG.

Evaluation of the FreeStyle Libre, a flash glucose monitoring system, in client-owned cats with diabetes mellitus

“…Our recommendation would be to use cyanoacrylate to fix the sensors onto the skin. 35,37 We found a very strong positive correlation between IG and BG in the diabetic cats, similar to other studies in dogs and cats. [33][34][35][36][37] The correlation was better if the sensor was located on the thorax (r = 0.91) vs the dorsal neck (r = 0.63).…”

“…We found a very strong positive correlation between IG and BG in the diabetic cats, similar to other studies in dogs and cats. 33 – 37 The correlation was better if the sensor was located on the thorax (r = 0.91) vs the dorsal neck (r = 0.63). This difference has not been described previously.…”

“… 6 , 20 , 22 , 33 – 35 To date, only a few studies have been published regarding the use of the FreeStyle Libre in dogs and cats, 13 , 33 – 41 with only four of them specifically in cats. 13 , 35 , 37 , 40 …”

Feline Comorbidities: Clinical perspective on diabetes mellitus and pancreatitis

“…With motivated owners who have a calm diabetic cat, the use of a continuous (or flash) glucose monitoring system (eg, FreeStyle Libre; Abbott Laboratories), which measures interstitial glucose, can be proposed, and the sensor applied, within the first weeks of treatment (Figure 2). 34 Aiming for normal or near-normal blood glucose concentrations is not recommended, as this increases the risk of hypoglycaemia. Most diabetic cats are considered well controlled if their blood glucose is maintained at between 80 and 200 mg/dl (4.4–11.1 mmol/l).…”

Clinical Use of a 180-Day Implantable Glucose Monitoring System in Dogs with Diabetes Mellitus: A Case Series

“…Continuous glucose monitoring systems (CGMSs) are frequently used in humans with diabetes, and clinical studies have shown they are effective in reducing hypoglycemia and improving glycemic control [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Thanks to their high performance, CGMSs have gained popularity among veterinarians and are increasingly being used in diabetic dogs (DD) and cats [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. CGMSs measure, using a transcutaneous sensor, interstitial glucose (IG) concentration, which reflects the blood glucose (BG) concentration [ 10 , 20 , 21 ].…”