Evaluation of Inaccuracies in the Measurement of Glycemia in the Laboratory, by Glucose Meters, and Through Measurement of Hemoglobin A1c

Abstract

IN BRIEF The accurate measurement of glucose is extremely important in the diagnosis of diabetes and pre-diabetes, where the laboratory values are crucial; in the management of diabetes, where glucose meter values are crucial; and in attainment of goals in diabetes, where hemoglobin A1c measurement is crucial. This article reviews pitfalls that may interfere with accuracy of glucose measurement in each of these three areas and how this inaccuracy may be evaluated and managed in the primary care setting. Three case presentations of disparity are discussed.

Glycemic Control and Hemoglobinopathy: When A1C May Not Be Reliable

“…A number of factors, including blood sampling technique and improper meter calibration, may potentially affect reliability of blood glucose meter readings. 18 Questionable reliability of blood glucose records, particularly Evidence-Based Clinical Decision Making the underreporting of high blood glucose values, 32 suggests that downloading of blood glucose meters provides more complete and valid blood glucose monitoring data compared to self-reporting using logbooks. A recent study 33 compared laboratorydetermined venous blood glucose values with simultaneous readings from two modern glucose meters and found high accuracy of meter values.…”

Trends in diabetes and obesity in Samoa over 35 years, 1978–2013

“…In both the present study, and in the published results of the 2003 SFSOD and 2010 GWAS, T2DM was assessed as fasting serum glucose ≥7.0mmol/L and/or on medication for T2DM. Biological studies have shown there are no clinically significant differences between measuring glucose in serum or plasma [17,18], although WHO and IDF recommend that glucose should be measured in venous plasma [10]. In this study serum glucose values were converted to plasma-equivalents using: − 0.137+1.047x , where x is serum glucose (mmol/L) [19].…”

Inhibition of Glycolysis for Glucose Estimation in Plasma: Recent Guidelines and their Implications

“…However, in most laboratory panels, serum is the most suitable sample for all other chemistries performed, and so ''panel'' glucose is usually serum glucose. The requirement that serum samples must be allowed to clot before serum glucose is tested significantly increases turnaround time for glucose results compared with plasma results [11]. There is also some suggestion that clotting consumes glucose [6].…”