Hip sensor location for flash interstitial glucose monitoring system provides adequate clinical accuracy in non-diabetic hypoglycemic dogs

Abstract

OBJECTIVE Flash glucose monitoring systems (FGMS) are frequently used for interstitial glucose monitoring in dogs with diabetes mellitus and are typically placed between the scapulae. We aimed to evaluate the variability between glucose measurements from FGMS placed in 2 locations (between the scapulae and over the hip) in non-diabetic dogs during rapidly induced hypoglycemia. ANIMALS 24 apparently healthy colony dogs that were subjects in a teaching laboratory. PROCEDURES Prospective interventional study. FGMS sensors (FreeStyle Libre 14-day system) were placed between the scapulae and over the hip of all dogs. Regular insulin was administered (0.3 u/kg IV) and subsequent hypoglycemia was cor-rected. Before insulin administration and every 10 minutes over 90 minutes, interstitial glucose was recorded from both locations, and blood glucose was measured with a point-of-care blood glucose monitor (AlphaTRAK 2). RESULTS There was a constant bias of 5.6 mg/dL (95% limits of agreement: −26.3 to 37.5 mg/dL) between locations, but the proportional bias was not apparent. There was a correlation between FGMS locations (r = 0.731, P = < .001). Sensor site B was clinically accurate with 100% of paired samples within Parkes error grid zones A (83%) and B (17%) but did not meet the criteria for analytical accuracy. CLINICAL RELEVANCE In this model of induced hypoglycemia in healthy dogs, variation between measurements from FGMS locations was unlikely to have affected the clinical outcome. Placement of FGMS over the hip may be an acceptable alternative to placement between the scapulae, but the utility in hyperglycemic dogs is unknown.