All about the Hemoglobin A1C Test

What is the A1C test?

The A1C test is a blood test that offers details about a person’s typical levels of blood sugar, likewise called blood sugar level, over the previous 3 months. The A1C test is in some cases called the hemoglobin A1c, HbA1c, or glycohemoglobin test. The A1C test is the main test used for diabetes management and diabetes research.

How does the A1C test work?

The A1C test is based on the attachment of glucose to hemoglobin, the protein in red blood cells that carries oxygen. In the body, red cell are constantly forming and dying, but generally they live for about 3 months. Thus, the HbA1c test reflects the average of an individual’s blood sugar levels over the past 3 months. The A1C test outcome is reported as a portion. The greater the percentage, the higher an individual’s blood sugar levels have actually been. A normal A1C level is listed below 5.7 percent.

Can the A1C test be used to diagnose type 2 diabetes and prediabetes?

Yes. In 2009, an international professional committee advised the A1C test as one of the tests available to assist identify type 2 diabetes and prediabetes. Previously, only the conventional blood glucose tests were used to identify diabetes and prediabetes.

Since the A1C test does not need fasting and blood can be drawn for the test at any time of day, specialists are hoping its benefit will permit more people to get evaluated — hence, decreasing the number of people with undiagnosed diabetes. However, some medical companies continue to suggest utilizing blood sugar tests for diagnosis.

Why should an individual be checked for diabetes?

Evaluating is particularly essential due to the fact that early in the disease diabetes has no symptoms. Although no test is best, the HbA1c and blood glucose tests are the best tools readily available to detect diabetes — a major and lifelong disease.

Testing makes it possible for healthcare providers to discover and treat diabetes prior to complications occur and to discover and treat prediabetes, which can delay or avoid type 2 diabetes from establishing.

Has the A1C test enhanced?

Yes. A1C laboratory tests are now standardized. In the past, the A1C test was not advised for diagnosis of type 2 diabetes and prediabetes due to the fact that the lots of different types of A1C tests could provide diverse outcomes. The precision has been improved by the National Glycohemoglobin Standardization Program (NGSP), which established standards for the A1C tests.

The NGSP certifies that makers of A1C tests provide tests that are consistent with those used in a major diabetes study. The study established existing A1C objectives for blood glucose control that can decrease the occurrence of diabetes complications, such as blindness and blood vessel disease.

How is the HbA1C test used to diagnose type 2 diabetes and prediabetes?

The A1C test can be used to detect type 2 diabetes and prediabetes alone or in mix with other diabetes tests. When the A1C test is used for medical diagnosis, the blood sample must be sent out to a lab that uses an NGSP-certified method for analysis to make sure the results are standardized.

Blood samples examined in a health care supplier’s office, called point-of-care (POC) tests, are not standardized for identifying diabetes. The following table supplies the portions that indicate medical diagnoses of normal, diabetes, and prediabetes according to A1C levels.

Diagnosis	A1C Level
Normal	below 5.7 percent
Diabetes	6.5 percent or above
Prediabetes	5.7 to 6.4 percent

* Any test for diagnosis of diabetes requires verification with a second measurement unless there are clear symptoms of diabetes.

Having prediabetes is a risk aspect for getting type 2 diabetes. Individuals with prediabetes might be retested each year. Within the prediabetes A1C range of 5.7 to 6.4 percent, the greater the A1C, the greater the risk of diabetes. Those with prediabetes are likely to develop type 2 diabetes within 10 years, however they can take steps to avoid or delay diabetes.

Is the A1C test used during pregnancy?

The A1C test may be used at the first see to the healthcare service provider during pregnancy to see if women with risk factors had undiagnosed diabetes prior to becoming pregnant. After that, the oral glucose tolerance test (OGTT) is used to test for diabetes that develops during pregnancy — known as gestational diabetes. After delivery, women who had gestational diabetes needs to be checked for persistent diabetes. Blood sugar tests, rather than the A1C test, should be used for testing within 12 weeks of delivery.

Can blood glucose tests still be used for diagnosing type 2 diabetes and prediabetes?

Yes. The basic blood sugar tests used for detecting type 2 diabetes and prediabetes-the fasting plasma glucose (FPG) test and the OGTT — are still recommended. The random plasma glucose test, likewise called the casual glucose test, may be used for detecting diabetes when symptoms of diabetes exist. In many cases, the A1C test is used to help healthcare providers confirm the outcomes of a blood glucose test.

Can the A1C test lead to a various medical diagnosis than the blood sugar tests?

Yes. In some individuals, a blood sugar test might show a medical diagnosis of diabetes while an A1C test does not. The reverse can also take place — an A1C test might indicate a medical diagnosis of diabetes even though a blood glucose test does not. Since of these variations in test results, health care suppliers repeat tests prior to making a diagnosis.

Individuals with varying test results may be in an early stage of the disease, where blood glucose levels have not risen high enough to reveal on every test. Sometimes, making basic changes in lifestyle — losing a percentage of weight and increasing exercise — can assist individuals in this early stage reverse diabetes or delay its beginning.

Can the A1C test offer false results?

Yes, for some people. The A1C test can be unreliable for identifying or monitoring diabetes in individuals with specific conditions that are understood to disrupt the outcomes. Interference ought to be thought when A1C results seem extremely various from the results of a blood sugar test.

Individuals of African, Mediterranean, or Southeast Asian descent, or individuals with member of the family with sickle cell anemia or a thalassemia are especially at risk of interference. Individuals in these groups may have a less typical kind of hemoglobin, called a hemoglobin variation, that can disrupt some A1C tests. The majority of people with a hemoglobin variation have no symptoms and might unknown that they carry this kind of hemoglobin.

Not all of the A1C tests are undependable for people with a hemoglobin version. People with false results from one kind of A1C test might require a different type of A1C test for determining their average blood sugar level. The NGSP offers details for healthcare providers about which A1C tests are proper to use for particular hemoglobin versions at www.ngsp.org.

False A1C outcomes might likewise happen in people with other issues that impact their blood or hemoglobin. For instance, a falsely low A1C outcome can occur in individuals with

• anemia
• heavy bleeding

An incorrectly elevated A1C result can occur in people who

• are really low in iron, for instance, those with iron deficiency anemia

Other causes of false A1C outcomes consist of

• kidney failure
• liver disease

How is the A1C test used after medical diagnosis of diabetes?

Health care providers can use the A1C test to monitor blood sugar levels in people with type 1 or type 2 diabetes. The A1C test is not used to monitor gestational diabetes.

The American Diabetes Association recommends that people with diabetes who are conference treatment objectives and have steady blood glucose levels have the A1C test two times a year. Healthcare suppliers might repeat the A1C test as often as 4 times a year until blood glucose levels reach recommended levels.

The A1C test helps healthcare suppliers change medication to minimize the risk of long-lasting diabetes complications. Research studies have actually shown significant decreases in long-term complications with the lowering of A1C levels.

When the A1C test is used for keeping an eye on blood sugar levels in a person with diabetes, the blood sample can be examined in a healthcare provider’s workplace utilizing a POC test to give immediate results. However, POC tests are less dependable and not as accurate as most lab tests.

How does the A1C associate with approximated typical glucose?

Approximated average glucose (eAG) is computed from the A1C. Some labs report eAG with the A1C test outcomes. The eAG number assists people with diabetes relate their A1C to everyday glucose tracking levels. The eAG calculation converts the A1C portion to the same units used by home glucose meters — milligrams per deciliter (mg/dL).

The eAG number will not match day-to-day glucose readings due to the fact that it is a long-term average instead of the blood sugar level at a single time, as determined with the home glucose meter. The following table shows the relationship between the A1C and the eAG.

Relationship in between A1C and eAG

A1C level	Estimated average blood sugar level
5 percent	97 mg/dL (5.4 mmol/L)
6 percent	126 mg/dL (7 mmol/L)
7 percent	154 mg/dL (8.5 mmol/L)
8 percent	183 mg/dL (10.2 mmol/L)
9 percent	212 mg/dL (11.8 mmol/L)
10 percent	240 mg/dL (13.3 mmol/L)
11 percent	269 mg/dL (14.9 mmol/L)
12 percent	298 mg/dL (16.5 mmol/L)
13 percent	326 mg/dL (18.1 mmol/L)
14 percent	355 mg/dL (19.7 mmol/L)

What A1C target should people have?

People will have different A1C targets depending on their diabetes history and their general health. Individuals need to discuss their A1C target with their health care supplier. Research studies have revealed that individuals with diabetes can lower the risk of diabetes complications by keeping A1C levels listed below 7 percent.

Maintaining great blood glucose control will benefit those with new-onset diabetes for many years to come. Nevertheless, an A1C level that is safe for one person may not be safe for another. For instance, keeping an A1C level listed below 7 percent may not be safe if it results in issues with hypoglycemia, also called low blood sugar.

Less stringent blood glucose control, or an A1C in between 7 and 8 percent — or even higher in some circumstances — may be suitable in people who have

• restricted life-expectancy
• long-standing diabetes and trouble obtaining a lower objective
• severe hypoglycemia
• sophisticated diabetes complications such as chronic kidney disease, nerve issues, or heart disease

Will the A1C test reveal changes in blood sugar levels?

Big changes in an individual’s blood glucose levels over the previous month will appear in their A1C test outcome, but the A1C does not show abrupt, temporary boosts or decreases in blood glucose levels. Although the A1C represents a long-term average, blood sugar levels within the previous 30 days have a greater effect on the A1C reading than those in previous months.

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