Test Code HbA1c Glycated Haemoglobin A1c (HbA1c)
Laboratory Code
LAB90
Specimen Requirements
Specimen Type: Whole Blood (EDTA)
Container/Tube: Lavender Top
Volume: 3.0 mL
Minimum Volume: 2.0 mL
Specimen Stability
| Specimen Type | Whole blood (EDTA) |
|---|---|
| Ambient | 1 day |
| Refrigerate | 14 days (preferred) |
| Frozen | Reject |
Methodology
High Performance Liquid Chromatography (HPLC)
Days and Times Performed
Monday through Friday, TAT 1 - 3 days
Specimen Condition
| Haemolysis | OK |
|---|---|
| Icterus | OK |
| Lipaemia | OK |
| Others: Frozen specimens | Reject |
Reference Interval
| HbA1c (NGSP) | (IFCC) |
|---|---|
| 4.0 – 6.0% | 20 – 42 mmol/mol |
HbA1c may be used as an initial screening test for Diabetes Mellitus (DM)
| HbA1c (NGSP) | (IFCC) | Interpretation |
|---|---|---|
| ≤ 6.0% | ≤ 42 mmol/mol | suggests a low probability of DM |
| 6.1 – 6.9% | 43 – 52 mmol/mol | to consider further testing of fasting plasma glucose (FPG) or oral glucose tolerance test (OGTT) |
| ≥ 7.0% | ≥ 53 mmol/mol | indicates a high probability of DM |
HbA1c used for monitoring of DM should have individualised targets based on the patient's health status. In general, a target of ≤ 7.0% provides a reasonable balance between reduction of microvascular complications and risk of hypoglycemia.
Source: MOH Guidelines Circular 08/2019; ACE Clinical Guidelines (ACG) 2023
Testing Laboratory
National University Hospital
Clinical Chemistry, 67724399
Useful For
Long term monitoring of glucose control in diabetes
Service Code
31939
LOINC Code Information
| HbA1c (%) | 17856-6 |
|---|---|
| HbA1c (mmol/mol) (NUHS) | 59261-8 |
Alias
GHB
Update
Last updated 27/01/2026