22 February 2012
Sense from Consensus
After months of often tedious discussion, the use of HbA1C as a diagnostic tool has taken a final step towards universal acceptance with the publishing of the findings of an “expert consensus group” on whether we, in the UK should follow the guidance of the World Health Organisation (WHO) or pursue a little diagnostic furrow of our own.
The group comprised what appear to be almost all the great and the good from the world of Diabetes in the UK, and so what they say should be worthy of attention. It is.
They have pronounced on various contentious issues and appear in every case to have got it right.
For instance, they do not rule out point-of-care testing providing the users have adequate training and the quality control is adequate.
They also detail the situations where HbA1C should not be used for diagnosis. These mainly reflect the point that HbA1C effectively gives an average blood glucose estimation for the previous 2-3 months. Hence in diabetes of acute onset, for instance in children, HbA1C should not be used because it may remain within normal limits for some weeks after the onset of symptoms until the new higher levels of blood glucose glycosylate hæmoglobin at a new higher rate.
They even offer simple guidance on what to do when the test is within normal limits using the relatively new term of “high risk of diabetes” which was formally known as Impaired Glucose Tolerance or Pre-Diabetes.
This guidance is so important that we make no excuse for publishing the full summary, which can be found in the Resources section of our website.
The guidance has been published in many places, one of these being the magazine Practical Diabetes. Further on in the magazine can be found what one hopes will be the last stand of the Luddites. They claim that HbA1C diagnosis has a high misclassification rate of nearly 50%. This sounds alarming until it is realised that they have selected a group for their research that is specifically excluded by the consensus group from HbA1C diagnosis; namely “patients at high risk of diabetes who are acutely ill”. They used as their sample patients with possible acute coronary syndrome; a group noted for their tendency to high blood glucose levels and where the HbA1C has not yet had time to change.
This paper should be ignored.
Find out more on our Diabetes Management distance learning course, which is always up to date with the very latest developments in the field.