The A1c test misses many cases of diabetes

The use of a hemoglobin A1c blood test to diagnose diabetes tends to underestimate the prevalence of the disease, according to a new study to be presented Saturday, March 23 at the ENDO 2019, the annual meeting of the Endocrine Society in New Orleans, La

"Based on our findings, A1c should not be used solely to determine the prevalence of diabetes," said lead researcher Maria Mercedes Chang Villacreses, City of the Institute of Diabetes and Metabolism Research. Hope in Duarte, California. in conjunction with the oral glucose test for increased accuracy. "

Hemoglobin A1c is a test that shows the average level of sugar in the blood during the last two to three months. People with diabetes usually undergo this test to determine if their blood sugar level stays within the set limits. This test is also used to diagnose type 1 and type 2 diabetes. It is often used to diagnose diabetes because no fasting or preparation is necessary.

A glucose tolerance test, also called oral glucose tolerance test, measures the body's response to sugar (glucose). In this test, a person's blood is taken after a night fast, then two hours after drinking a sweet drink. The glucose tolerance test can be used to screen for type 2 diabetes.

The new study involved 9,000 adults without a diagnosis of diabetes. Participants had both an A1c test and an oral glucose tolerance test, and the researchers compared the results. The researchers found that the A1c test did not detect 73% of diabetes cases detected by the oral glucose test. "The A1c test showed that these people had normal blood sugar levels, whereas they did not have any," said Chang Villacreses.

The researchers also found that race and ethnicity had a significant impact on the accuracy of A1c. He was more likely to detect abnormal glucose levels in non-Hispanic whites than in non-Hispanic blacks or Hispanics.

"Our results indicate that the prevalence of diabetes and normal glucose tolerance defined only by A1c is very unreliable, with a significant tendency to underestimate the prevalence of diabetes and overestimate normal glucose tolerance" , said Chang Villacreses.

Provided by
The endocrine society