The ADA's updated 2018 guidelines include recommendations for screening and criteria for the diagnosis of diabetes.
The ADA recommends using any of these four criteria for diabetes diagnosis (four testing options):
- Hemoglobin A1C ≥6.5%* - Perform in laboratory using National Glycohemoglobin Standardization Program (NGSP)-certified method and standardized to the Diabetes Control and Complications Trial (DCCT) assay.
- Fasting plasma glucose (FPG) ≥126 mg/dL (7.0 mmol/L)* - Fasting defined as no caloric intake for ≥8 hours.
- 2-hour plasma glucose (PG) ≥200 mg/dL (11.1 mmol/L) during oral glucose tolerance test (OGTT) (75-g)* - Performed as described by the World Health Organization (WHO), using glucose load containing the equivalent of 75 g anhydrous glucose dissolved in water.
- Random plasma glucose (PG) ≥200 mg/dL (11.1 mmol/L) - In persons with symptoms of hyperglycemia or hyperglycemic crisis.
* In the absence of unequivocal hyperglycemia results should be confirmed using repeat testing.
* Unless clinical diagnosis is clear, same test to be repeated using a new blood sample for confirmation.
* Two discordant results? Result above cut point should be repeated.
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