DID YOU KNOW: A1c Fails to Diagnose 50% of Diabetes and Prediabetes in Arabs
Race and ethnicity may influence A1c results and, therefore, the diagnostic accuracy of the test. Researchers examined the sensitivity and specificity of A1c as a diagnostic test for diabetes and prediabetes in 482 non-pregnant Arab adults.
A1c levels were 5.9% in 52 individuals with undiagnosed diabetes, 5.2% in 223 individuals with prediabetes, and 5.0% in 207 individuals with normal glucose tolerance.
Using the most accurate A1c cut-points of 6.2% for diabetes and 5.1% for prediabetes still failed to diagnose 73% of those with diabetes and 31% of those with prediabetes.
A1c results alone correctly identified 5% of individuals with diabetes identified by OGTT, 13% by fasting plasma glucose, and 41% by both criteria.
Similarly, A1c results alone correctly identified 14% of individuals with impaired glucose tolerance, 9% with impaired fasting glucose, and 33% with both abnormalities.
“In summary,” the investigators conclude, “measurement of A1C alone in Arabs results in a high proportion of false-negative test results for both diabetes and prediabetes, which may lead to delayed diagnosis and potential progression of diabetes-related complications.
J Clin Endocrinol Metab 2011 online August 17