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HEMOGLOBIN A1C(GLYCOSYLATED HEMOGLOBIN)

Item Value
Available Stat? No
Test code HA1C
Performed by? Chemistry
Sendout? no
Price range $$
In House Availability Daily, Mon - Fri
Principle Ion exchange high performance liquid chromatography (HPLC) for separation of hemoglobin A1c (HbA1c) from hemoglobins A1a, A1b, Ao, S, C and F. The hemoglobin A1c fractions are measured by absorption of light at 415 nm.

Interpretation Goals for HbA1c management recommended by American Diabetes Association (ADA) Standards of Medical Care in Diabetes (Diabetes Care, Volume 33, Supplement 1, January 2010) are as follows:

When using this assay, the ADA recommended goal for A1c control for adult diabetic patients in general is < 7% although use of an A1c goal as close to normal as possible without causing significant hypoglycemia may be appropriate for individual patients. In pregnant patients with diabetes, the ADA recommends aiming for the range < 6% if it can be achieved without excessive hypoglycemia.

The ADA recommended goals for other age groups are:

0-6 years old 7.6% - 8.4%
6-12 years old < 8%
13-19 years old < 7.5%
> 19 years < 7%


The American Diabetes Association recommends the following HbA1c cutoffs when assessing increased risk for diabetes and when diagnosing diabetes:

5.7% - 6.4% Increased risk for diabetes
> 6.4% Consistent with diabetes


Receiver operating curve analyses of nationally representative U.S. data (NHANES 2005–2006) indicate that among the nondiabetic adult population, an A1C value of 5.7%, compared with other cutoff points, has the best combination of sensitivity (39%) and specificity (91%) to identify cases of impaired fasting glucose (FPG ≥ 100 mg/dL [5.6 mmol/L]). Note that individuals with an A1c < 5.7% may still be at risk, depending on the level of A1c and presence of other risk factors, such as obesity and family history. Individuals with an A1c > 6% should be considered at very high risk for diabetes.

This method has been certified by the NGSP as having documented traceability to the Diabetes Control and Complication Trial (DCCT).
Container type EDTA (lavender top) tube
Amount to Collect 4 mL
Sample type Whole blood
Min. Volume 1.0 mL
Normal range < 5.7%
Synonyms Glycosylated Hemoglobin;
Stability 24 hours at room temperature, 7 days at 2-8°C.
Interferences Hemoglobin F > 25 % causes falsely lowered hemoglobin A1c values. Patients with hemolytic disease have lower than normal hemoglobin A1c values due to shortened life span of the red blood cells.

Turn around times 24 hours
References 1. Gestational Diabetes Mellitus. American Diabetes Association: Clinical Practice Recommendations 2001. Diabetes Care. Volume 24; Supplement 1, 2001.

2. Goldstein DE, et al: Clinical Application of Glycosylated Hemoglobin Measurements. Diabetes, 31:3, June 1982.

3. Instruction Manual for Variant(TM) II Hemoglobin A1c Program. 702:001-6. Nov 2001. BioRad Laboratories, Hercules, CA.

4. Nathan, D.M. et al. "The Clinical Information Value of the Glycosylated Hemoglobin Assay", N. Eng. J. Med. 1984, 310, 341-346.

5. Sacks et al., Guidelines and recommendations for laboratory analysis in the diagnosis and management of diabetes mellitus, Clin Chem 48:3; 436-472, 2002.
CPT coding 83036
Last Updated 7/11/2013 2:17:58 PM
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