Routine A1C tests conducted by physicians may help detect type 2 diabetes in people who haven’t been diagnosed, according to researchers from Duke University.
In a cross-sectional, observational study published in the January 2002 issue of the Journal of General Internal Medicine, doctors from the Veterans’ Affairs Medical Center screened 1,253 men ages 45 to 64 for diabetes using an A1C test. They then followed up with a fasting blood-glucose test for those who had an A1C of 6% or higher. Diabetes was defined as having an A1C of 7% or higher or a fasting blood-glucose level of 126 mg/dl or greater. Height, weight, blood pressure, fasting lipids and urine protein levels were also measured.
A total of 4.5 percent of the subjects were diagnosed with type 2
diabetes-consistent with the estimated figure of undiagnosed diabetes in the general population. Factors associated with diabetes were hypertension, obesity and family history of diabetes. Researchers state that having a primary care doctor does not change the risk of having undiagnosed diabetes.
A1C and fasting blood-glucose testing “may be a preferred method” for detecting undiagnosed diabetes, conclude the researchers.
Clinical adviser’s note: Currently in the United States, the laboratory test hemoglobin A1c (A1C) is not approved for use in diagnosing diabetes. An A1C level of 7% compares to an average blood glucose of 150 mg/dl for the previous two to three months. The A1C is the gold standard for monitoring long-term glycemic control of diabetes.