A1C ≥6.5%. The test should be performed in a laboratory using a method that is NGSP certified and standardized to the Diabetes Control and Complications Trial (DCCT) assay; or

fasting plasma glucose (FPG) ≥126 mg/dL (7.0 mmol/L). Fasting is defined as no caloric intake for at least 8 h; or

2-h plasma glucose ≥200 mg/dL (11.1 mmol/L) during an oral glucose tolerance test (OGTT). The test should be performed as described by the World Health Organization, using a glucose load containing the equivalent of 75 g anhydrous glucose dissolved in water; or

in a patient with classic symptoms of hyperglycemia or hyperglycemic crisis, a random plasma glucose ≥200 mg/dL (11.1 mmol/L);

in the absence of unequivocal hyperglycemia, result should be confirmed by repeat testing.

Testing to detect type 2 diabetes and prediabetes in asymptomatic people should be considered in adults of any age who are overweight or obese (BMI ≥25 kg/m²) and who have one or more additional risk factors for diabetes (see Table 4 of the “Standards of Medical Care in Diabetes—2013”). In those without these risk factors, testing should begin at age 45 years. (B)

If tests are normal, repeat testing at least at 3-year intervals is reasonable. (E)

To test for diabetes or prediabetes, the A1C, FPG, or 75-g 2-h OGTT are appropriate. (B)

In those identified with prediabetes, identify and, if appropriate, treat other cardiovascular disease (CVD) risk factors. (B)

Testing to detect type 2 diabetes and prediabetes should be considered in children and adolescents who are overweight and who have two or more additional risk factors for diabetes (see Table 5 of the “Standards of Medical Care in Diabetes—2013”). (E)

Consider referring relatives of those with type 1 diabetes for antibody testing for risk assessment in the setting of a clinical research study. (E) …