The hemoglobin A1C test is a test that is commonly used to determine if patients have diabetes. A study last year in February 2017, by the American Medical Association found that this test is less accurate for black people with the sickle cell anemia trait. Read the original article from upi.com here.
With the A1C test, a result of 5.7 or higher means the patient has prediabetes or diabetes. Anything that falls below 5.7 is a normal reading and the patient does not have diabetes according to the American Diabetes Association. The A1C test measures red blood cells for high blood sugar levels.
People with sickle cell anemia trait had A1C test levels that were significantly lower than in people without the trait, which can tell people wrongly that they are not diabetic or pre-diabetic when in fact they are.
Clinicians are being informed about this test. What makes it even harder to predict or control, however, is that the test affects those with sickle cell trait, not those who have the disease. Sickle cell anemia is a disease that is inherited and disturbs the hemoglobin in red blood cells and makes it sickle shaped instead of the normal rounded shape. However, people with the trait often have no symptoms and may not even know they possess the trait at all. Almost 10% of African Americans in the US have the sickle cell trait.
Study and Results
4,000 people were examined in the study on the A1C test last year. The group had their blood sugar measured with the A1C test as well as a fasting blood sugar test and the results saw that 29% of black people with sickle cell anemia trait were diagnosed with prediabetes compared to 49% of study participants who did not have the sickle cell trait. The inaccuracy and under diagnosing of diabetes with the A1C test is apparent!
If the A1C test is inaccurate for black people with sickle cell anemia trait, this means there may be delays in diagnosis of diabetes and consequently delayed treatment.
One doctor said he was not surprised at the findings of the study. Dr. Zonszein a director of a clinical diabetes center in New York knows that the A1C test is not perfect. He explains that although it is a popular test, since patients do not have to fast beforehand, it has its flaws. In fact, a previous study has shown that those with kidney failure, late pregnancy, anemia, and other blood disorders can also have skewed test results with the A1C test.
It is important that patients and health care providers know the sickle cell trait in black people can interfere with the accuracy of the A1C test for diagnosis of diabetes so that they can take proper precautions and prevent wrong diagnosis.