The evolution and future of diagnostic criteria for diabetes mellitus

Background: The diagnostic criteria for diabetes mellitus have evolved over time, taking into account new evidence. Here, the author would like to review the evolution of diagnostic criteria for diabetes mellitus, the current diagnostic criteria, and future perspectives.Current Concepts: For the first time, in 1965, the World Health Organization (WHO) recommended that a 2-hour plasma glucose concentration of 130 mg/dL or more after taking a 50-g or 100-g oral glucose bolus may be used to make the diagnosis in people younger than 45 years and that other clinical data might be used to make the diagnosis in people older than 45 years. The 2003 American Diabetes Association Diagnostic Criteria set the threshold for normal fasting glucose at 100 mg/dL. The International Expert Committee (IEC) in 2009, the American Diabetes Association in 2010, and the WHO in 2011 proposed new diagnostic criteria for diabetes: glycated hemoglobin (HbA1c) of 6.5% or higher. More recently, diabetes has been diagnosed via a fasting blood glucose of 126 mg/dL or higher after fasting for at least 8 hours, a 2-hour postprandial blood glucose of 200 mg/dL or higher, glycated hemoglobin of 6.5% or higher, or a random blood glucose of 200 mg/dL or higher with symptoms of hyperglycemia.Discussion and Conclusion: Further research is needed on the accuracy of other markers, such as HbA1c, fructosamine, and 1,5-anhydroglusitol, in the diagnosis of diabetes, and sufficient evidence is required to determine whether it is appropriate to use the same diagnostic criteria for diabetes in aged people and different ethnic groups.