Prediabetes: IFG, IGT, Increased A1C
In 1997 and 2003, the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus1,2 recognized an intermediate group of individuals whose glucose levels, although not meeting criteria for diabetes, are nevertheless too high to be considered normal This group was defined as having impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) IFG: fasting plasma glucose (FPG) of 100–125 mg/dL (5.6–6.9 mmol/L)* IGT: 2-hour plasma glucose (2-h PG) in the 75-g oral glucose tolerance test (OGTT) of 140–199 mg/dL (7.8–11.0 mmol/L) Individuals with IFG and/or IGT have been referred to as having prediabetes, indicating a relatively high risk for future development of diabetes IFG and IGT should not be viewed as clinical entities in their own right but rather risk factors for diabetes as well as cardiovascular disease (CVD) IFG and IGT are associated with obesity (especially abdominal or visceral obesity), dyslipidemia with high triglycerides and/or low HDL cholesterol, and hypertension Individuals with an A1C of 5.7–6.4% should be informed of their increased risk for diabetes as well as CVD and counseled about effective strategies to lower their risks (see Section IV. Prevention/Delay of Type 2 Diabetes) *The World Health Organization (WHO) and a number of other diabetes organizations define the cutoff for IFG at 110 mg/dL (6.1 mmol/L)11References Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Diabetes Care 1997;20:1183-1197. Genuth S, Alberti KG, Bennett P, et al., for the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Follow-up report on the diagnosis of diabetes mellitus. Diabetes Care 2003;26:3160-3167. American Diabetes Association. Standards of medical care in diabetes—2013. Diabetes Care 2013;36(suppl 1):S13; Table 3.