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Blood Sciences

Blood Test Information

(a.k.a Glycated Haemolglobin)
minimum sample volume required ~ 1ml

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Tube type: EDTA

Special instructions
Microvette collection tubes for paediatric samples are also acceptable.
Interfering substances - some haemoglobin variants.
Add on time limit = 3 days

For known diabetes monitoring: 60 days minimum re-test interval.

For diagnosis of asymptomatic diabetes: if HbA1c >47 mmol/mol, repeat within 2 weeks to confirm the diagnosis.

Reference range
See clinical application section below

mmol/mol HbA0

Turnaround Time
2 days

Department: Haematology

Clinical Application
HbA1c may give false indication of glycaemia if rapidly changing or if abnormal red cell turnover e.g. anaemia, chronic liver disease, CKD 4 & 5, haemoglobinopathies .

For monitoring diabetes:
Treatment targets: 48 mmol/mol (53 mmol/mol in type 2
diabetes if on a drug associated with hypoglycaemia) but individualised
treatment advised (NICE NG15 and 28).

For diagnosis of diabetes:
HbA1c <42 mmol/mol: Not consistent with diabetes mellitus.
HbA1c 42-47 mmol/mol: High diabetes risk.
HbA1c >47 mmol/mol: Diagnostic of diabetes mellitus.

For further information, please refer to the guidelines linked below.

» Diagnosis of Diabetes Mellitus guidelines


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