The danger of using inappropriate point-of-care glucose meters in patients on icodextrin dialysis

• Published in: Diabetic medicine Vol. 28; no. 10; pp. 1272 - 1276
• Main Authors: Perera, N. J., Stewart, P. M., Williams, P. F., Chua, E. L., Yue, D. K., Twigg, S. M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-10-2011; Blackwell
• Subjects: Autoanalysis - instrumentation; Biological and medical sciences; Blood Glucose - drug effects; blood glucose measurement; Dialysis Solutions - adverse effects; Endocrinopathies; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; Glucans - adverse effects; Glucans - blood; Glucose - adverse effects; glucose meter; Humans; hypoglycaemia; icodextrin interference; Medical sciences; Peritoneal Dialysis, Continuous Ambulatory; Predictive Value of Tests; Reference Standards; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: endocrinology; Human; Icodextrin; Obesity; Point-of-care testing; Glucometer; Nutrition; hypoglycaemia; Nutrition disorder; Interference; Dextrin; Patient; Metabolic diseases; Hypoglycemia; Point of care testing; Danger; Dialysis; blood glucose measurement; icodextrin interference; Polysaccharide; Endocrinology; Nutritional status; Glycemia; glucose meter
• ISSN: 0742-3071; 1464-5491
• DOI: 10.1111/j.1464-5491.2011.03362.x

Diabet. Med. 28, 1272–1276 (2011)
Aims  Icodextrin is a glucose polymer used to maintain an osmotic gradient in peritoneal dialysis. Metabolites of icodextrin are known to cause overestimation of blood glucose in glucose meters using glucose dehydrogenase/pyrroloquinolinequinone systems. The aim of this study is to determine the extent of icodextrin interference in glucose meters using the newer glucose dehydrogenase/NAD or glucose oxidase systems. This has not been established previously.
Methods  Fasting blood samples (n = 4) were spiked with either one icodextrin metabolite (maltose, maltotriose or maltotetraose) or a combination, at various blood concentrations expected during dialysis. Samples were tested in triplicate on: five glucose‐meters, a Radiometer® (glucose oxidase/hydrogen peroxide) and laboratory (hexokinase) analysers. Each meter was also tested on blood from six patients undergoing dialysis. Accuracy was evaluated as % Bias = [(meter glucose – laboratory glucose)/laboratory glucose] × 100.
Results  A single icodextrin metabolite affected glucose measurements and, in combination, the interferences were additive in the two Accu‐Chek® and Optium® Xceed meters by > 10%. Amongst these meters, the Optium Xceed 5‐s machine was less affected. Meters using glucose oxidase were least affected by interference. A similar trend in interference was observed in vivo.
Conclusion  While meters using glucose dehydrogenase/NAD are less affected by icodextrin metabolites, interference can still be demonstrated. The degree of interference can vary in different glucose meters using this enzyme/cofactor system, as seen in the Optium Xceed machines. Icodextrin is an important source of interference that sometimes even experienced professionals are unaware of and which leads to clinically significant errors in insulin dose adjustment. Awareness of this interference and selection of the most appropriate glucose meters are crucial to minimize this hazard.