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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Hemoglobin A1C

Test Code(s): A1C / HA1C

CPT Code(s): 83036

Test Description: Test Component:

A1C is measured and reported along with the estimated Average Glucose (eAG).

Methodology: Ion Exchange Chromatography/Spectrometry

Clinical Significance: Hemoglobin A1C is the major subfraction of glycated hemoglobin. Glycated hemoglobin is the combination of glucose with hemoglobin in a nonenzymatic reaction, which is continuous during the lifespan of the erythrocyte. The concentration of HbA1C provides an index of the adequacy of long term blood glucose control in patients with diabetes. The HbA1C level indicates the glucose control over the previous 8 to 10 weeks, whereas blood glucose reflects the metabolic control for only the previous 24 hours. Intravenous glucose therapy does not typically affect the HbA1C level.

Conditions that affect erythrocyte turnover (hemolysis, blood loss) and hemoglobin variants must be considered, particularly when the A1c result does not correlate with the patient's clinical presentation.

Days Performed: Daily.

Turnaround Time: Stat: Not available stat.
Routine: Next working day.

Specimen Requirements

Specimen: Blood

Collection Container: Preferred: Lavender top

Collection Volume: Preferred: 4 mL
Pediatrics: 1 mL

Sample Analyzed: Whole Blood

Volume Required: Preferred: 2.5 mL
Pediatrics: 0.5 mL

Specimen Processing: Refrigerate specimen.

Specimen Transport: Transport specimen to UWHC Core Laboratory (B4/220). Transport with coolant pack if coming from outreach location.

Stability: Ambient: 24 hours
Refrigerated: 7 days
Frozen: Not acceptable



Reference interval:   

         4.3-6.0 %

  6 years and up
Interpretive guideline:   
   Level of control

             < 7.1 %


          7.1-8.0 %


          8.1-9.0 %


             > 9.0 %




Test Limitations:

Hemoglobin A1C requests more frequent than 60 days will automatically be cancelled by the laboratory as a duplicate request.

Additional Information:

The NGSP has certified this method and its reagents as having documented traceability to the Diabetes Control and Complications Trial Reference Method.


An estimated Average Glucose (eAG) is provided with the A1C result. 


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