|Evaluation for type 2 diabetes should be performed within the health care setting. Patients should be screened at 3-year intervals beginning at age 45; testing should be considered at an earlier age or be carried out more frequently if diabetes risk factors are present.||E|
|Diabetes risk factors include a family history of diabetes; overweight defined as BMI ≥25 kg/m2; habitual physical inactivity; belonging to a high-risk ethnic or racial group; previously identified IFG or IGT; hypertension; dyslipidemia; history of GDM or delivery of a baby weighing >9 lbs; and polycystic ovary syndrome.||B|
|The FPG is the recommended screening test. The OGTT may be necessary for the diagnosis of diabetes when the FPG is normal. The FPG is preferred for screenings because it is faster and easier to perform, more convenient, acceptable to patients, and less expensive.||C|
|Diagnostic testing should be performed in any clinical situation in which such testing is warranted; health care providers should not consider whether a person meets screening criteria in such cases.||E|
|Screening outside of health care settings, or community screening, has not been shown to be beneficial and may result in some harm; this type of screening is not recommended.||E|
↵* Scientific evidence was ranked based on the American Diabetes Association’s grading system. The highest ranking (A) was assigned when there is supportive evidence from well-conducted generalizable randomized controlled trials that are adequately powered, including evidence from a meta-analysis that incorporated quality ratings in the analysis. An intermediate ranking (B) was given to supportive evidence from well-conducted cohort studies, registries, or case-control studies. A lower rank (C) was assigned to evidence from uncontrolled or poorly controlled studies or when there is conflicting evidence with the weight of the evidence supporting the recommendation. Expert consensus (E) is indicated, as appropriate. For a detailed description of this grading system, refer to Diabetes Care 25 (Suppl. 1):S1, 2002.