Abstract:
In New Zealand laboratories the measurement of glycated haemoglobin (HbA1c) for diagnosis of diabetes is now only reported in SI units of mmol/mol. HbA1c is now recommended as the preferred test to diagnose diabetes in most circumstances. The requirement for a second positive test in asymptomatic individuals is retained. An HbA1c ≥50 mmol/mol (repeated on a second occasion in asymptomatic patients) is diagnostic of diabetes and a value ≤40 mmol/mol represents normal glucose tolerance. For patients with an initial HbA1c result of 41–49 mmol/mol, cardiovascular risk assessment and lifestyle interventions are recommended with repeat HbA1c screening in 6–12 months. For patients whose HbA1c is ≤40 mmol/mol, repeat screening (including for CVD risk) at intermittent intervals is recommended as per published guidelines.