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Test Code HBA1C Hemoglobin A1c, Blood

Reporting Name

Hemoglobin A1c, B

Useful For

Evaluating the long-term control of blood glucose concentrations in patients with diabetes

 

Diagnosing diabetes

 

Identifying patients at increased risk for diabetes (prediabetes)

 

This assay is not useful in determining day-to-day glucose control and should not be used to replace daily home testing of blood glucose.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Whole Blood EDTA


Specimen Required


Container/Tube: Lavender top (EDTA)

Specimen Volume: 3 mL

Collection Instructions: Send specimen in original tube. Do not aliquot.


Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole Blood EDTA Refrigerated (preferred) 7 days
  Frozen  7 days
  Ambient  24 hours

Reference Values

4.0-5.6%

<18 years: Hemoglobin A1c criteria for diagnosing diabetes have not been established for patients who are <18 years of age.

≥18 years: Increased risk for diabetes (prediabetes): 5.7-6.4%

Diabetes: ≥6.5%

 

Interpretive information based on Diagnosis and Classification of Diabetes Mellitus, American Diabetes Association.

Day(s) Performed

Monday through Sunday

CPT Code Information

83036

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HBA1C Hemoglobin A1c, B 4548-4

 

Result ID Test Result Name Result LOINC Value
HBA1C Hemoglobin A1c, B 4548-4

Interpretation

Diagnosing diabetes: American Diabetes Association (ADA)

-Hemoglobin A1c (HbA1c): ≥6.5%

 

Therapeutic goals for glycemic control (ADA)

-Adults:

 - Goal of therapy: < 7.0% HbA1c

 - Action suggested: > 8.0% HbA1c

-Pediatric patients:

 - Toddlers and preschoolers: < 8.5% (but >7.5%)

 - School age (6-12 years): < 8%

 - Adolescents and young adults (13-19 years): < 7.5%

 

The ADA recommendations for clinical practice suggest maintaining a HbA1c value closer to normal yields improved microvascular outcomes for diabetics.(1) Target goals of less than 7% may be beneficial in patients such as those with short duration of diabetes, long life expectancy, and no significant cardiovascular disease. However, in patients with significant complications of diabetes, limited life expectancy, or extensive comorbid conditions, targeting a less than 7% goal may not be appropriate.

 

Since the HbA1c assay reflects long-term fluctuations in blood glucose concentration, a patient with diabetes who has come under good control in recent weeks may still have a high concentration of HbA1c. The converse is true for a patient with diabetes previously under good control who is now poorly controlled.

 

HbA1c results less than 4.0% are reported with the comment: "Falsely low HbA1c results may be observed in patients with clinical conditions that shorten erythrocyte life span or decrease mean erythrocyte age. HbA1c may not accurately reflect glycemic control when clinical conditions that affect erythrocyte survival are present. Fructosamine may be used as an alternate measurement of glycemic control."

Report Available

Same day/1 day

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Method Name

Ion-Exchange High-Performance Liquid Chromatography (HPLC)