HbA1c

What is HbA1c?

HbA1c is a laboratory test that is used for the diagnosis and evaluation of diabetes mellitus, both type 1 and 2. When the levels of sugar are high in the blood, the excess sugar binds to hemoglobin through a process called glycation and results in the formation of HbA1c; the HbA1c test measures the amount of this hemoglobin A that is linked to sugar. As the life span of red blood cells that carry hemoglobin is about 120 days, HbA1c test predicts the sugar levels over the past 8-12 weeks, thus providing a measure of how well sugar levels in the body were maintained over the past 2-3 months.

Alternate names

• Glycated Hemoglobin
• Hemoglobin A1c
• A1c
• Hb1c

Is the HbA1c procedure an elective or an emergency procedure?

HbA1c is generally done as an elective procedure.

Types

HbA1c may be measured in the laboratory using the following methods:

• Immunoassay
• Boronate affinity chromatography
• High-performance liquid chromatography
• Enzymatic assay
• Capillary electrophoresis

Indications

HbA1c is indicated for the following:

• Diagnosis of prediabetes
• Diagnosis of type 1 and type 2 diabetes
• Monitoring the response to diabetes treatment

Contraindications & Risk factors

Factors that can negatively influence the results of an HbA1c test include:

• Recent blood transfusion
• Recent severe blood loss
• Anemia
• Pregnancy
• Presence of hemoglobin variants other than hemoglobin A

Preoperative advice

No special advice or preparation is needed.

Intraoperative details

The procedure is done as a simple lab test, where a sample of blood is drawn from a vein in the arm and sent to the laboratory for analysis.

Post-operative advice

No specials care or precautions are required after the test.

Role of diet/ Exercise/ Lifestyle changes

No lifestyle modifications or measures are needed before or after the test.

Complications

There are no complications associated with the HbA1c test.

Prognosis

The HbA1c is a standard and reliable test that is very useful in the diagnosis and management of type 1 and type 2 diabetes mellitus. The results may vary depending on the technique used for analysis. It is a good predictor tool for the assessment of the effectiveness of treatment as well as for modification of treatment. Individuals with high HbA1c levels are at a greater risk of developing complications and severe disease.

When to contact the doctor or hospital? / Indications for hospitalization if required

Hospitalization is not required for the HbA1c test.

Suggested clinical specialist/ Departments to consult for this procedure

• General Medicine
• Endocrinology

Additional Information

The results of the HbA1c test may be interpreted as follows:

• A1c level less than 5.7% – normal
• A1c level 5.7 - 6.4% – prediabetes
• A1c level more than 6.5% – diabetes

For individuals with diabetes the results indicate the following:

• A1c levels less than 7% - good control
• A1c levels 7-8% - unsatisfactory control
• A1c levels more than 8% - poor control