Screening for Diabetes and Pre-Diabetes With Proposed A1C-Based Diagnostic Criteria

• Published in: Diabetes care Vol. 33; no. 10; pp. 2184 - 2189
• Main Authors: Olson, Darin E, Rhee, Mary K, Herrick, Kirsten, Ziemer, David C, Twombly, Jennifer G, Phillips, Lawrence S
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Diabetes Association 01-10-2010
• Subjects: African Americans; Biological and medical sciences; Care and treatment; Clinical medicine; Diabetes; Diabetes Mellitus - diagnosis; Diabetes Mellitus - metabolism; Diabetes. Impaired glucose tolerance; Diabetic retinopathy; Diagnosis; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Female; Glucose Tolerance Test; Glucose tolerance tests; Glycated Hemoglobin A - metabolism; Health economics; Health services; Humans; Male; Medical sciences; Medical screening; Metabolic diseases; Methods; Middle Aged; Miscellaneous; Original Research; Plasma; Prediabetic State - diagnosis; Prediabetic State - metabolism; Public health. Hygiene; Public health. Hygiene-occupational medicine; R&D; Race; Research & development; Studies; United States; Endocrinopathy; Human; Nutrition; Criterion; Hemoglobin A1c; Diabetes mellitus; Metabolic diseases; Diagnosis; Medical screening; Endocrinology
• ISSN: 0149-5992; 1935-5548
• DOI: 10.2337/dc10-0433

OBJECTIVE: An International Expert Committee (IEC) and the American Diabetes Association (ADA) proposed diagnostic criteria for diabetes and pre-diabetes based on A1C levels. We hypothesized that screening for diabetes and pre-diabetes with A1C measurements would differ from using oral glucose tolerance tests (OGTT). RESEARCH DESIGN AND METHODS: We compared pre-diabetes, dysglycemia (diabetes or pre-diabetes), and diabetes identified by the proposed criteria (A1C ≥6.5% for diabetes and 6.0-6.4% [IEC] or 5.7-6.4% [ADA] for high risk/pre-diabetes) with standard OGTT diagnoses in three datasets. Non-Hispanic white or black adults without known diabetes who had A1C and 75-g OGTT measurements were included from the prospective Screening for Impaired Glucose Tolerance study (n = 1,581), and from the National Health and Nutrition Examination Survey (NHANES) III (n = 2014), and NHANES 2005-2006 (n = 1,111). RESULTS: OGTTs revealed pre-diabetes in 35.8% and diabetes in 5.2% of combined study subjects. A1C provided receiver operating characteristic (ROC) curve areas for diabetes of 0.79-0.83, but ROC curve areas were [less-than or equal to]0.70 for dysglycemia or pre-diabetes. The proposed criteria missed 70% of individuals with diabetes, 71-84% with dysglycemia, and 82-94% with pre-diabetes. Compared with the IEC criteria, the ADA criteria for pre-diabetes resulted in fewer false-negative and more false-positive result. There were also racial differences, with false-positive results being more common in black subjects and false-negative results being more common in white subjects. With use of NHANES 2005-2006 data, ~5.9 million non-Hispanic U.S. adults with unrecognized diabetes and 43-52 million with pre-diabetes would be missed by screening with A1C. CONCLUSIONS: The proposed A1C diagnostic criteria are insensitive and racially discrepant for screening, missing most Americans with undiagnosed diabetes and pre-diabetes.