Diagnosing type 2 diabetes and identifying high-risk individuals using the new glycated haemoglobin (HbA1c) criteria

摘要

In the February 2013 issue of the BJGP there are several interesting and useful articles about aspects of diabetes, but I would like to question just one aspect stated in the Clinical Intelligence article by Gholap and colleagues.Basing diagnosis on an HbA1c result has significant advantages, which are outlined in the article. They say that the HbA1 c level reflects average glucose levels over the preceding 6-8 weeks (later giving the clinical situations in which that may not be the case). And they say that in a patient without symptoms any 'diagnostic' level test result needs to be repeated, or supported by another kind of test, to confirm a diagnosis with such important long-term implications. So-far-so-good. But I think it is incorrect to say that you can use an HbA1c level repeated just 2 weeks later. At this point the test result will largely cover exactly the same time period as the first, and thus it will confirm that the first test result was accurate. In order for it truly to be a 'second test' one needs to delay repeating HbA1c for at least 6-8 weeks, so that the result reflects a different time period. This is a disadvantage of relying on HbA1c.