Glucose Detection and Concentration Estimation in Feline Urine Samples with the Bayer Multistix and Purina Glucotest

Abstract

The Bayer Multistix are commonly used for detection and estimation of feline glucosuria by veterinarians and cat owners. A newer product, the Purina Glucotest, utilizes the same enzymatic technology for detection of glucose, but has been designed for home use as a litter additive that allows interpretation of glucosuria over an 8-h period. The objectives of this study were to assess the sensitivity, specificity, and accuracy of the Glucotest and Multistix, and to assess the 8-h color stability of the Glucotest. Overall, the Glucotest had greater sensitivity and specificity than the Multistix, and more accurately estimated urine glucose concentration if evaluated at least 30 min after exposure to urine. A significant lack of agreement between the results obtained immediately after exposure to urine vs after 30 min and 8 h contradicts the 8-h color stability claim, but the change in urine glucose concentration estimation over time resulted in improved test accuracy at the 30 and 480 min time points.

Basal glucosuria in cats

“…Blood samples had been stored for up to 5 hr and although cooled, had neither been separated from blood cells nor fluorinated. In contrast to urinary glucose, which is stable for at least 5 days if stored at 4°C (Fletcher, Behrend, Welles, Lee, & Hosgood, ), blood glucose may drop by as much as 7% per hour if no anti‐glycolytic agents are added (van den Berg, Thelen, Salden, van Thiel, & Boonen, ). Non‐standardized preanalytical specimen handling was also the reason why fractional glucose excretion was not calculated.…”

Feline Diabetes Mellitus

“…The Glucotest was read immediately after exposure to urine and at different time points thereafter over the course of 8 hours. At the initial reading, the test was inaccurate in 22 % of samples (21% overestimation, 1% underestimation); the inaccuracy decreased to 10% and 3% when the test was read at 30 minutes and 8 hours, respectively (Fletcher et al, 2011).…”

Semiquantitative Glukosemessungen in Katzenharnproben und in mit Harn verklumpter Einstreu

“…Obwohl die Verwendung automatischer Teststreifen-Analysegeräte auch in dieser Studie die Ergebnisse wahrscheinlich optimiert hätte [6](6), wurde im Hinblick auf den Einsatz der Teststreifen zuhause durch den Besitzer darauf verzichtet. Mit 0,759 deutlich schlechter war die Spezifität von Multistix in der Studie von Fletcher et al [8] (8). Die Autoren schlussfolgerten, dass Multistix die tatsächliche Glukosekonzentration regelmäßig überschätzt und der Einsatz dieser Teststreifen zu problematischen Therapieentscheidungen führen würde.…”

“…Studien bei der Katze stehen aus. Da bei nicht azotämischen, euthyreoten, normoglykämischen Katzen eine Harnglukosekonzentration von 1,48 mmol/l (26,675 mg/dl) nur ausnahmsweise überschritten wird [28], sprechen positive Glukosebefunde bei Verwendung der derzeit für die Katze validierten Harnteststreifen Multistix (Bayer [8]), Aution 10PA und 10EA (Arkray [6]) sowie Combur9 Test ® (Roche [12]) für eine Hyperglykämie oder renale Glukosurie. Betont werden muss, dass auch eine stressassoziierte Hyperglykämie zu positiven Harnglukosebefunden führen kann.…”