Hemoglobin A1c

Test Code

GHBP

Alias/See Also

Glycated Hgb

CPT Codes
83036

Includes

Estimated Average Glucose

Preferred Specimen

WHOLE BLOOD, EDTA

Minimum Volume

250 uL microtainer or 1 mL EDTA

Instructions

NEW EDTA TUBES FOR BLOOD BANK ARE ACCEPTABLE

Transport Container

LAV/1

Transport Temperature

ROOM TEMP. OR 2-8 DEGREES, C

Specimen Stability

24 HOURS AT ROOM TEMP, 7 DAYS WHEN STORED AT 2-8 DEGREES C

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

CLOTTED SAMPLE, FIBRIN STRANDS, SAMPLE TOO OLD

Methodology
Ion-Exchange High-Performance Liquid Chromatography (HPLC)

Setup Schedule

Daily upon Receipt

Report Available

Upon Completion of Analysis

Limitations

PTS WITH HEMOLYTIC ANEMIA, POLYCYTHEMIA, POST SPLENECTOMY

Reference Range

< 6.0% = Non-Diabetic Level

<7.0% = Goal*

>8.0% = Action Suggested**

*high risk of developing long-term complications such as retinopathy, nephropathy, neuropathy and cardiopathy. Action suggested depends on individual patient circumstances.

**Some danger of hypoglycemic reaction in type I diabetics. Some glucose intolerant individuals and 'sub-clinical' diabetics may demonstrate (elevated) A1c in this area.

Clinical Significance

Diabetes mellitus is a condition characterized by hyperglycemia resulting from the body’s inability to use blood glucose for energy. In Type 1 diabetes, the pancreas no longer makes insulin and therefore, blood glucose cannot enter the cells to be used for energy. In Type 2 diabetes, either the pancreas does not make enough insulin or the body is unable to use insulin correctly. The complications of diabetes, involving the eyes, kidneys, nerves and the large blood vessels of the heart, brain and extremities, are common to both forms of the disease. Diabetes mellitus affects more than 5% of the world population.

Therapy for diabetes requires the long-term maintenance of a blood glucose level as close as possible to a normal level, minimizing the risk of long-term vascular consequences. A single fasting blood glucose measurement is an indication of the patient’s immediate past condition (hours), but may not represent the true status of blood glucose regulation. An accurate index of the mean blood glucose concentration may be established by the measurement of hemoglobin A1C (HbA1C) every two to three months. HbA1C, the glycohemoglobin of interest, is formed in two steps by the nonenzymatic glycation of HbA. The first step is the formation of an unstable aldimine (labile A1C, or pre- A1C), a reversible reaction between the carbonyl group of glucose and the N terminal valine of the ß-chain of hemoglobin. Labile A1C formation is directly proportional to the blood glucose concentration. During red blood cell circulation, some of the labile A1C is converted (Amadori rearrangement)to form a stable ketoamine, HbA1C. The level of HbA1C is proportional to both the average glucose concentration and the life span of the red blood cell in the circulation. The measurement of HbA1C has therefore been accepted for the clinical management of diabetes.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.