The following guidance is provided for the diagnosis of diabetes:
Normal - Fasting plasma glucose (FPG) <6 mmol/l. HbA1c <42 mmol/mol. 2-h PG <7.8 mmol/l
Diabetes mellitus - A1C ≥ 48 mmol/mol (6.5%), FPG 7.0 mmol/l, 2-h PG >11.1 mmol/l; randomPG >11.1 mmol/l
In the absence of unequivocal symptomatic hyperglycaemia, the diagnosis of diabetes must be confirmed on a subsequent day (no delay) by repeat measurement, repeating the same test for confirmation. If two tests don't agree then repeat the one that suggests diabetes.
NB: Please click on the ppt presentation to view situations when HbA1c is not reliable for diagnosis and for guidance on diabetes risk identification.