Common Diabetes Test Has New Advantage

The hemoglobin A1c blood test (HbA1c) most commonly used to monitor glucose levels in patients already diagnosed with diabetes may have additional detection capabilities. A consensus statement published in the July issue of the Journal of Clinical Endocrinology and Metabolism indicates that the HbA1c test could be used to identify millions of people with undiagnosed diabetes.

The test, originally used to monitor long-term glucose control, is now being identified as a useful screening and diagnosis tool. A national panel comprised of diabetologists, pathologists, and internists met to review the relevant studies and tests. They recommended that patients scoring at least 6% on the HbA1c test “may have or be at risk for diabetes,” and that their doctor schedule additional plasma glucose (PG)-specific tests to confirm a diagnosis. The panel also outlined that patients scoring a 6.5% or above should be considered diabetic and undergo further PG-specific tests.

Christopher Saudek, MD, professor of endocrinology and metabolism at Johns Hopkins, director of the Johns Hopkins Comprehensive Diabetes Center, and lead author of the consensus statement, noted the many advantages of the HbA1c test, which allow for it to be a valuable screening tool. The test does not require the patient to fast before their blood is drawn, and the results are not affected by other short-term changes in diet or exercise. Because patients often modify their behavior before health screenings, the test’s resistance to these changes makes it particularly useful in identifying diabetes patients, in particular high-risk patients.

It is estimated that six million people have undiagnosed diabetes—one-third of all diabetes patients are unaware they have it—and these patients may go an average of seven years between onset and diagnosis. This poses serious health risks to a significant percentage of the population. The HbA1c test’s ability to prevent serious consequences is certainly needed.

As diabetes continues to be an issue of growing concern, does the heavier burden fall on the patient or the physician? Someone else? Who takes responsibility for the undiagnosed cases, and what else must be done to see that patients no longer go undiagnosed?