My blood sugar levels have been normal for almost three years with just one diabetes pill each evening. Is it possible that I was misdiagnosed? At the time my diabetes was discovered, I was very anemic. Could anemia affect the results of a glycosylated hemoglobin test? If so, by how much?

It sounds like you might have been diagnosed based on a Hemoglobin A1c result. This test should not be used to diagnose diabetes. The American Diabetes Association recommends using a fasting glucose on more than one occasion or an oral glucose tolerance test to make the diagnosis. For more information, see Classification and Diagnosis of Diabetes

JTL

[Editor’s comment: The A1c test does depend on a stable hemoglobin level in the bloodstream. So it is possible that if your anemia and hemoglobin levels were changing, the hemoglobin A1c level might have been influenced, but this usually results in a lowering of the A1c. One exception is fetal hemoglobin that is picked up by some versions of the A1c test, and falsely elevates the reading. This possibility can be verified by doing hemoglobin fraction testing, and using a different method to measure hemoglobin A1c if the need to do so is found. That would double-check if the high value were from out-of-control diabetes or from the abnormal hemoglobin.

WWQ]