Diagnosis of Gestational Diabetes Mellitus Will Be Flawed until We Can Measure Glucose

• Published in: Clinical chemistry (Baltimore, Md.) Vol. 66; no. 2; pp. 265 - 267
• Main Authors: Bruns, David E, Metzger, Boyd E, Sacks, David B
• Format: Journal Article
• Language: English
• Published: England American Association for Clinical Chemistry, Inc 01-02-2020; Oxford University Press
• Subjects: Accuracy; Blood; Blood Glucose; Centrifugation; Dextrose; Diabetes; Diabetes in pregnancy; Diabetes mellitus; Diabetes, Gestational; Diagnosis; Diagnostic systems; Error analysis; Ethylenediaminetetraacetic acid; Female; Fluorides; Gestational diabetes; Glucose; Glucose Tolerance Test; Hemoglobin; Humans; Hyperglycemia; Laboratories; Likelihood ratio; Measurement; Measuring instruments; Point-of-Care Systems; Pregnancy; Prospective Studies; Room temperature; Variability; diagnostic accuracy; preanalytical error; Gestational diabetes mellitus; diagnostic sensitivity and specificity; glycemia; HAPO; citrate-fluoride-EDTA tubes
• ISSN: 0009-9147; 1530-8561
• DOI: 10.1093/clinchem/hvz027

Glucose is lost from whole blood samples at a rate of 5%-7% per hour at room temperature (8). [...]loss of glucose at 1 h exceeds the desirable limit of total analytical error for glucose based on biological variation. [...]variation in time to centrifugation of blood samples introduces variability in glucose results with resultant variability in likelihood of diagnosis of GDM. [...]these authors have evaluated the potential of glucose meters, used at the point of care, to improve the diagnostic accuracy of testing for GDM by minimizing the loss of glucose before analysis (12). [...]they measured glucose in skin-puncture blood at the POC, with samples collected from patients in the fasting state and at 1 and 2 h after a 75-gram oral glucose load. Using a specificity of 95% (rather than 100%), the positive likelihood ratio is >17. [...]a positive result connotes a large, >45%, increase in post-test probability of GDM.