Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus

Publication Date: July 20, 2023
Last Updated: July 24, 2023

GLUCOSE

  • Fasting glucose should be measured in venous plasma when used to establish the diagnosis of diabetes, with a value ≥7.0 mmol/L (≥126 mg/dL) diagnostic of diabetes.
    • A (high)
  • Screening by hemoglobin A1c (Hb A1c), FPG or 2-h OGTT is recommended for individuals who are at high risk of diabetes. If Hb A1c is <5.7% (<39 mmol/mol), FPG is <5.6 mmol/L (<100 mg/dL), and/or 2-h plasma glucose is <7.8 mmol/L (<140 mg/dL), testing should be repeated at 3-year intervals.
    • B (moderate)
  • Glucose should be measured in venous plasma when used for screening of high-risk individuals.
    • B (moderate)
  • Plasma glucose should be measured in an accredited laboratory when used for diagnosis of or screening for diabetes.
    • GPP (good practice point)
  • Blood for fasting plasma glucose analysis should be drawn in the morning after the subject has fasted overnight (at least 8 h).
    • B (low)
  • To minimize glycolysis, a tube containing a rapidly effective glycolytic inhibitor such as granulated citrate buffer should be used for collecting the sample. If this cannot be achieved, the sample tube should immediately be placed in an ice-water slurry and subjected to centrifugation to remove the cells within 15 to 30 min. Tubes with only enolase inhibitors such as sodium fluoride should not be relied on to prevent glycolysis.
    • B (moderate)
  • Based on biological variation, glucose measurement should have analytical imprecision ≤2.4%, bias ≤2.1% and total error ≤6.1%. To avoid misclassification of individuals, the goal for glucose analysis should be to minimize total analytical error and methods should be without measurable bias.
    • B (moderate)

GLUCOSE METERS

  • Portable glucose meters should not be used in the diagnosis of diabetes, including gestational diabetes.
    • B (moderate)
  • Frequent blood glucose monitoring (BGM) is recommended for all people with diabetes who use intensive insulin regimens (with multiple daily injections or insulin pump therapy) and who are not using continuous glucose monitoring (CGM).
    • A (high)
  • Routine use of BGM is not recommended for people with type 2 diabetes treated with diet and/or oral agents alone.
    • A (high)
  • Individuals with diabetes should be instructed in the correct use of glucose meters, including technique of sample collection and use of quality control.
    • GPP
  • Glucose meters should report the glucose concentrations in plasma rather than in whole blood to facilitate comparison with plasma results of assays performed in accredited laboratories.
    • GPP
  • Glucose meters should meet relevant accuracy standards of the FDA in the US or comparable analytical performance specifications in other locations.
    • GPP
  • In hospitals and acute-care facilities, point-of-care testing personnel, including nurses, should use glucose meters that are intended for professional use.
    • GPP
  • When testing newborns, personnel should use only meters that are intended for use in newborns.
    • GPP
  • Unless CGM is used, people using multiple daily injections of insulin should be encouraged to perform BGM at a frequency appropriate for their insulin dosage regimen, typically at least 4 times per day.
    • B (moderate)
  • Manufacturers should continue to improve the analytical performance of meters.
    • GPP

Overview

Title

Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus

Authoring Organizations