Glucose: A Simple Molecule That Is Not Simple to Quantify

Small increments in blood glucose substantially increase the risk of developing diabetes mellitus; but preanalytical and analytical variables, such as the absence of harmonization for glucose assays, make it difficult to correctly apply these epidemiological insights to individual patients. Harmonization can be improved if 3 variables are addressed: changing proficiency test grading from consensus based to accuracy based, effectively controlling glycolysis, and taking into account the time of day blood was collected.The continuous and graded quantitative relationship of fasting glucose measurements to the risk of developing diabetes was well documented recently by Tirosh et al.(1). They found an increased risk of type 2 diabetes across quintiles of fasting plasma glucose (FPG) concentrations within the newly defined reference range, <5.55 mmol/L (<100 mg/dL). For example, a person with an FPG between 4.83 and 5.00 mmol/L (87 and 90 mg/dL) has an age-adjusted risk of developing diabetes that is 1.81 times that of a person with an FPG <4.55 mmol/L (82 mg/dL; 95% CI 1.16–2.83). Thus, a difference as small as 0.28 mmol/L (5 mg/dL) nearly doubles the risk. Higher concentrations of FPG …