Dear WWood56,
To answer your question, a fasting test is normally conducted first thing in the morning after the body has been resting overnight and the body's blood/glucose level has had time to level off and settle back to what is refered to as the 'Basal' level. Having not eaten anything/drunk anything for approx 12 hours (exception being plain water only) there should be no 'energy' added to the 'Basal' or reference level and this reading will hence show what is the Basal level. The reading will only be for that particular day and time period unlike the HbA1c blood test which gives a result as to what were your mean/average Blood/Glucose levels over the 12 weeks that preceeded the point where the blood test was taken.
These days the NHS is tending to follow the WHO reccomendations,and from the HbA1c result alone it is now possible to say if someone has or has not got diabetes. This will usually be followed up with either the 'Fasting' blood test or sometimes with a OGTT just to confirm the initial diagnosis. The 'Fasting test and HbA1c test though similar are not in effect the same thing.
Where a fasting test has been undertaken, the time when it was taken should also be noted as varients in results by 0.28 mmol/L are know to exist between a morning and afternoon blood test, so that in many cases the Dr will make the necessciary adjustment to the finalised result when it eventually come back in makin the diagnosis.
Also Ladies who had Gestational diabetes during pregnancy run an increased risk of developing diabetes at some later stage.
Hope this information is of some use to you, if you have any other question then please fee free to ask.
With mt best regards - Lazybones
