Assessment of postprandial hyperglycemia and circadian fluctuation of glucose concentrations in diabetic dogs using a flash glucose monitoring system

Abstract

Background: Postprandial hyperglycemia (PPH) and circadian glucose concentration fluctuations recorded in the home environment of dogs with naturally occurring diabetes mellitus (DM) have not been reported. Objectives: To determine if a flash glucose monitoring system (FGMS; FreeStyle Libre) can detect PPH and circadian fluctuations in glucose concentrations in dogs with variably controlled DM. Animals: Fourteen client-owned dogs with DM. Methods: Prospective observational study. Interstitial glucose (IG) concentrations measured by the FGMS during a 13-day study period were analyzed. Results: A total of 17, 446 FGMS IG concentrations were analyzed. For all dogs analyzed together, median IG concentration measured within 30 (288 mg/dL), 60 (286 mg/dL), 90 (285 mg/dL), and 120 (285 mg/dL) minutes of meals was each significantly higher than the median IG concentration at all other times (260 mg/dL, 259 mg/dL, 258 mg/dL, and 257 mg/dL, respectively; range, 40-500 mg/dL; P < .001 for each). Median night-time IG concentration measured from all dogs on 3,547 samples recorded between 1:00 am and 6:00 am (268 mg/dL; range, 40-500 mg/dL) was significantly higher than median IG measured on 13, 899 samples at all other time points (259 mg/dL; range, 40-500 mg/dL; P < .001). Conclusions and Clinical Importance: The FGMS can be used for future studies of PPH and circadian fluctuations of glucose concentrations in dogs with DM in their home environment.

Validation of a flash glucose monitoring system in outpatient diabetic cats

“…Shea) as previously described. 21 Briefly, an approximately 5 × 5 cm square area of skin on the dorsal neck was clipped and cleaned with dilute chlorhexidine followed by alcohol, and the area was allowed to dry fully for at least 1 minute. The sensor was placed according to the manufacturer's guidelines, with the addition of 3 to 4 drops of tissue glue on the adherent side of the sensor.…”

“…Data collection also was performed as previously described. 21 For each cat on day 0, the first blood sample was collected after a 1‐hour FGMS calibration period. A maximum of 2 mL was obtained from a peripheral or jugular vein for measurement of PCV, total protein concentration, point‐of‐care blood glucometer reading (POCG; Accu‐Chek Performa, Roche Diagnostics Corp, Indianapolis, Indiana), and blood glucose concentration measurement on the automated biochemistry analyzer (ABA; Vitros 4600 Chemistry System, Ortho‐Clinical Diagnostics, Rochester, New York).…”

“…Lin's concordance correlation coefficient ( ρ c ) was used to compare the gold standard ABA to FGMS and POCG glucose concentrations, as previously reported. 21 Bland‐Altman plots were generated to visually evaluate the correlations. A multivariable linear regression model was used to evaluate the effects of ABA, PCV, TP, hemolysis, lipemia, and icterus on FGMS glucose concentration measurements.…”

“…Two mixed effects models were fitted to the data to account for glucose variability among cats, as previously reported in dogs. 21 Interstitial glucose concentration was modeled as a function of blood glucose concentration as follows: with β 0 + β 1* (ABA measured blood glucose concentration) serving as the fixed effects of the model, the random effect occurring at the cat level, and an error term that is a function of undetermined factors such as within cat variability, sleep time, or mealtime. For the purpose of comparison, POCG glucose concentration measurements were similarly modeled as a function of blood glucose concentration as follows: …”

“…The FGMS has been validated in dogs with DM treated on an outpatient basis as well as in dogs hospitalized for diabetic ketoacidosis. 18 , 19 , 20 , 21 , 22 One study also has validated the FGMS in hospitalized diabetic cats. 23 In this study, the investigators used 8 sutures to attach the sensor to mostly nonsedated cats, a technique that could be unacceptable to some veterinarians and owners.…”