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What are normal a1c readings: Normal A1C levels and 15 ways to lower high A1C


Normal A1C levels and 15 ways to lower high A1C

The hemoglobin A1C test is the closest thing to a diabetes scorecard you can find. Whether someone has had diabetes mellitus for years or if they have just been diagnosed, they have probably heard about this test. Unlike blood sugar meters people use at home, the A1C measures an average blood sugar level over the past several months by analyzing how many of a patient’s hemoglobin cells have glucose attached to them. The test results keep track of how well a person is managing his or her diabetes. 

What does A1C stand for?

Hemoglobin A1C (HbA1C), commonly called A1C, stands for glycosylated hemoglobin. An A1C test (sometimes called the HbA1C test or glycohemoglobin test) provides information on how well-controlled a person’s diabetes is. “It does this by measuring the percentage of red blood cell hemoglobin protein that has sugar stuck to it and provides a three-month average of your blood glucose levels,” explains Marie Bellantoni, MD, a board-certified endocrinologist at the Center for Endocrinology at Mercy Medical in Baltimore. The higher blood sugar levels are, the more glucose attaches to hemoglobin. The results provide patients and their healthcare providers with information on how well their treatment, diet, and medication is working and whether adjustments are necessary.

RELATED: Diabetes medications and treatments

A1C test

There are a few reasons a doctor might suggest an A1C test:

  • To make a diagnosis of Type 2 diabetes
  • To test for prediabetes
  • To monitor blood sugar levels
  • To determine if treatment adjustments are needed

The A1C blood test is not for diagnosing Type 1 diabetes, gestational diabetes, or cystic fibrosis-related diabetes, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).  

Do you have to fast for an A1C blood test?

Unlike the fasting plasma glucose (FPG) and the OGTT tests, there is no need to fast before having the A1C test. If A1C test results indicate a person has or might have diabetes, a healthcare provider might suggest one of these tests to confirm the results. Another test, the random plasma glucose test, which does not require fasting, can also be used. If the results are borderline or if the results of the different tests do not match, a doctor might suggest repeating the test in several weeks or months. 

How accurate are A1C tests?

A1C levels rise well before the clinical onset of diabetes, making early diagnosis possible according to the 2017 Standards of Medical Care in Diabetes by the American Diabetes Association (ADA). Sometimes, however, in the early stages of diabetes, blood sugar levels are not high enough to show up as problematic. Testing environments, such as temperature in the lab, equipment used, and handling of samples, can affect the results; however, this is more common in the fasting plasma glucose and the OGTT than in the A1C. Strict quality controls and advancements in testing have made the A1C test more precise than in the past, according to the NIDDK. Doctors should be aware of laboratories that use an NGSP-certified method of testing for A1C levels. The NIDDK warns that blood samples taken at home or analyzed in a healthcare provider’s office should not be used for diagnosis. 

There are some health conditions and situations that might skew the results of the test. These include:

  • Anemia
  • Kidney failure
  • Liver disease
  • Sickle cell anemia
  • Erythropoietin treatment
  • Dialysis
  • Blood loss or blood transfusions

Also, the test can be unreliable for people of African, Mediterranean, or Southeast Asian descent, people with a family member with sickle cell anemia, and those with thalassemia. For those who fall into these groups, a healthcare provider might suggest a different test or a specialized A1C.

How often is A1C tested?

To keep A1C levels in check, patients should have the test repeated regularly. “If the A1C is less than 5.7, indicating you don’t have diabetes, you should have it checked every three years,” according to Robert Williams, MD, a family doctor and geriatrician in Lakewood, Colorado, and a medical advisor for eMediHealth. “If it is between 5.7 and 6.4, indicating you are at risk of developing diabetes, you should have it rechecked every one to two years. If you have a confirmed diabetes diagnosis, and your blood sugar is well-controlled, you should have an A1C test every six months. If you already have diabetes and your medications change, or your blood sugar is not well-controlled, you should have an A1C test every three months.” 

Normal A1C levels

There are some general guidelines for interpreting A1C results. However, there are also exceptions, according to the ADA. The general guidelines are:

  • Under 5.7: Non-diabetic
  • Between 5.7 and 6.4: Prediabetes
  • Between 6.0 and 6.9: Controlled diabetes
  • Between 7.0 and 8.9: Uncontrolled diabetes
  • Over 9.0: Critically high

For reference, normal A1C levels for people without diabetes is 4% to 5.6%.

What is a good A1C level?

Levels between 5.7 and 6.4 are considered prediabetes. For most people with diabetes, the general A1C goal is to have a level between 6.0 and 6.9. While it might sound like the ideal A1C target is under 6.0, for those with diabetes, this level can indicate low blood sugar levels, which can be just as dangerous as high blood sugar levels. If A1C results fall between 7.0 and 8.9, a doctor might suggest lifestyle changes or medications to help lower the levels to what is considered controlled. However, for some people, these levels might be appropriate, such as:

  • Those with a limited life expectancy
  • People with long-standing diabetes who have trouble reaching a lower goal
  • Those with severe hypoglycemia or the inability to sense hypoglycemia 

What is a dangerous level of A1C?

When levels rise to 9.0, the risk of kidney and eye damage and neuropathy increases. Some people who are newly diagnosed could have levels over 9.0. Lifestyle changes and possibly medication can lower levels quickly. For someone who has long-standing diabetes, levels rise above 9.0 could signal the need for a change in their treatment plan. 

Some labs estimate average blood glucose (eAG), which corresponds to home glucose meter readings (mg/dL), allowing patients to understand the results better. 

Why is my A1C high?

As blood sugar level rises, so do A1C levels. “A high A1C indicates that blood sugar control is not optimal. This in itself is not an emergency, but it gives your healthcare provider a picture of how blood glucose has, or has not, been controlled,” says Dr. Williams. 

Poor diabetes control or a need for medication adjustments might cause higher A1C. Diet changes, daily exercise, or medication adjustments might quickly lower A1C. Because Type 2 diabetes is a progressive disease, adjustments to one’s treatment might be a part of the process of controlling diabetes. Poor diabetes control does not always mean a patient is doing something wrong. But there are other reasons why levels might be high. 

As previously mentioned, other health conditions can cause skewed results. These include kidney disease, anemia, liver disease, asplenia, blood loss, hypothyroidism, uremia, and sickle cell anemia. Other factors that might lead to a high A1C level include increased age, pregnancy, and gestational diabetes.

Can you have high A1C and not be diabetic?

According to one 2009 study, 3.8% of people without a history of diabetes have an elevated A1C level (over 6.0). This group is more likely to have other risk factors for Type 2 diabetes and cardiovascular disease. Researchers found that the following groups were more likely to have an elevated A1C without having a diagnosis of diabetes:

  • Older
  • Male
  • Non-Hispanic black and Mexican American
  • Hypertension
  • Obesity
  • Higher C-reactive protein levels

A high A1C result might signal that there is a problem. “Even a modest increase in your blood sugar, above normal levels, can increase your risk of heart disease, even when you don’t have full-blown diabetes,” says Dr. Bellatoni. A physician can review test results and talk to patients about risk factors and lifestyle changes to improve blood sugar levels. 

How to lower your A1C levels

“It’s important to get your hemoglobin A1C levels as close to normal as possible,” says Dr. Bellatoni, “Decreasing your hemoglobin A1C decreases your risk of having complications from diabetes. Even if you cannot get your A1C back to the normal range, any improvement lowers your risk of diabetes complications.”

Diabetes tracking and treatment

  • Follow your diabetes treatment plan: Understand the treatment plan before leaving the healthcare provider’s office and discuss barriers (emotional, physical, financial) that could prevent you from following the program. Attend all follow-up visits. 
  • Consistently take prescribed medications: If a healthcare provider has prescribed medications to reduce blood sugar levels, take them regularly. Some people only take medication when they aren’t feeling well, but these medications don’t work unless taken consistently.
  • Monitor and track blood sugar: Regular blood sugar monitoring is the most important step in diabetes management, according to the CDC. Healthcare providers can inform patients of different types of meters and help patients find the best one for them. Providers can also tell patients how often to check their blood sugar and what their target blood sugar range is. Keep a log of your blood sugar levels to look for patterns and triggers for blood sugar spikes and lows. If you wear a continuous glucose monitor, you can use the data. Learning what causes blood sugar to rise or decrease can help you create a plan to keep it consistent.  

Diet changes

  • Weight loss: You might not need to lose as much weight as you think. A study published in 2019 found that people with Type 2 diabetes who reduced their body weight by 10% within five years of their diagnosis achieved remission from the disease. Work with a healthcare provider to come up with a weight loss goal. Work with a nutritionist or dietitian to help create a feasible meal plan. 
  • Plan grocery shopping and meals: Eating on the go often involves foods that are unhealthy. Take time to plan meals and use those to create a healthy grocery list.  
  • Don’t skip breakfast: A study published in the journal Obesity found that people who ate a large breakfast rich in protein and fat helped reduce A1C and blood pressure. 
  • Eat a healthy diet with proper portions: Aim for half of your plate to be low-starch vegetables, one-fourth lean protein, and one-fourth whole grains. Blood sugar levels can increase if you eat more than your body needs. Use food scales and measuring cups and spoons to make sure portions are appropriate. 
  • Monitor carbohydrate intake: Eat carbs that have high fiber and nutrients, such as whole grains, whole fruits and vegetables, and legumes. Avoid carbs like candy, cakes, white bread, rice, and pasta.
  • Stick to a meal schedule: Some people with diabetes find it best to eat at the same time each day. Certain diabetes medications or insulin can cause blood sugar to drop too low if you skip a meal, according to the NIDDK. Talk with a healthcare provider if you aren’t sure what the best meal schedule is. A nutritionist, dietitian, or certified diabetes educator (CDE) can help you find the right diet.

Lifestyle changes

  • Exercise regularly: Both aerobic and resistance training help to reduce glycemic control, according to a study published in 2016. Exercise improves blood glucose control, reduces cardiovascular risk factors, contributes to weight loss, and improves wellbeing. For people with prediabetes, regular exercise might prevent or delay Type 2 diabetes development. 
  • Keep moving: Keeping active makes the body more sensitive to insulin, according to the Centers for Disease Control and Prevention (CDC). Although regular exercise is important, daily activity is also considered moderate-intensity physical activity. Daily activities include gardening, walking, dancing, mowing the lawn, swimming, and even doing housework. 
  • Consider supplements: There is limited research into whether supplements and herbs can help lower blood sugar. For example, a review published in 2013 tested aloe vera for diabetes in rats and found it might help. Additionally, a study published in 2017 found people with prediabetes who used powdered fenugreek seed were less likely to receive a diagnosis of diabetes. And although the evidence is conflicting, a meta-analysis conducted in 2013 found consuming cinnamon significantly decreased glucose. The ADA doesn’t recommend cinnamon to reduce glucose, and it shouldn’t be a first-line treatment. Always talk to a healthcare provider before taking supplements.

Psychological adjustments

  • Use stress management tools: A study published in 2018 found that using mindfulness to reduce stress resulted in decreased A1C levels as well as increased wellbeing and general health. 
  • Avoid denial statements: Denial can take many forms, according to the ADA. Avoid saying (or thinking) things like, “One bite won’t hurt,” “I don’t have time to eat healthy today,” or “My diabetes isn’t serious.” 
  • Connect with other people who have diabetes: Feeling alone can make it more challenging to stick to a treatment plan. Find an in-person support group or look for one online. Connecting with other people who are in a similar situation can offer support, guidance, and accountability.  

Remember, A1C tests measure blood sugar levels over three months. Lifestyle and diet changes take several months before making a meaningful impact.

The A1C Test & Diabetes

On this page:

What is the A1C test?

The A1C test is a blood test that provides information about your average levels of blood glucose, also called blood sugar, over the past 3 months. The A1C test can be used to diagnose type 2 diabetes and prediabetes.1 The A1C test is also the primary test used for diabetes management.

An A1C test is a blood test that reflects your average blood glucose levels over the past 3 months.

The A1C test is sometimes called the hemoglobin A1C, HbA1c, glycated hemoglobin, or glycohemoglobin test. Hemoglobin is the part of a red blood cell that carries oxygen to the cells. Glucose attaches to or binds with hemoglobin in your blood cells, and the A1C test is based on this attachment of glucose to hemoglobin.

The higher the glucose level in your bloodstream, the more glucose will attach to the hemoglobin. The A1C test measures the amount of hemoglobin with attached glucose and reflects your average blood glucose levels over the past 3 months.

The A1C test result is reported as a percentage. The higher the percentage, the higher your blood glucose levels have been. A normal A1C level is below 5.7 percent.

Why should a person get the A1C test?

Testing can help health care professionals

  • find prediabetes and counsel you about lifestyle changes to help you delay or prevent type 2 diabetes
  • find type 2 diabetes
  • work with you to monitor the disease and help make treatment decisions to prevent complications

If you have risk factors for prediabetes or diabetes, talk with your doctor about whether you should be tested.

You may be able to prevent or delay type 2 diabetes with lifestyle changes such as weight loss or being physically active most days of the week.

How is the A1C test used to diagnose type 2 diabetes and prediabetes?

Health care professionals can use the A1C test alone or in combination with other diabetes tests to diagnose type 2 diabetes and prediabetes. You don’t have to fast before having your blood drawn for an A1C test, which means that blood can be drawn for the test at any time of the day.

If you don’t have symptoms but the A1C test shows you have diabetes or prediabetes, you should have a repeat test on a different day using the A1C test or one of the other diabetes tests to confirm the diagnosis.2

A1C results and what the numbers mean

*Any test used to diagnose diabetes requires confirmation with a second measurement, unless there are clear symptoms of diabetes.
Diagnosis* A1C Level
Normal below 5.7 percent
Prediabetes 5.7 to 6.4 percent
Diabetes 6.5 percent or above

When using the A1C test for diagnosis, your doctor will send your blood sample taken from a vein to a lab that uses an NGSP-certified method. The NGSP, formerly called the National Glycohemoglobin Standardization Program, certifies that makers of A1C tests provide results that are consistent and comparable with those used in the Diabetes Control and Complications Trial.

Blood samples analyzed in a doctor’s office or clinic, known as point-of-care tests, should not be used for diagnosis.

The A1C test should not be used to diagnose type 1 diabetes, gestational diabetes, or cystic fibrosis-related diabetes. The A1C test may give false results in people with certain conditions.

Having prediabetes is a risk factor for developing type 2 diabetes. Within the prediabetes A1C range of 5.7 to 6.4 percent, the higher the A1C, the greater the risk of diabetes.

Is the A1C test used during pregnancy?

Health care professionals may use the A1C test early in pregnancy to see if a woman with risk factors had undiagnosed diabetes before becoming pregnant. Since the A1C test reflects your average blood glucose levels over the past 3 months, testing early in pregnancy may include values reflecting time before you were pregnant. The glucose challenge test or the oral glucose tolerance test (OGTT) are used to check for gestational diabetes, usually between 24 and 28 weeks of pregnancy. If you had gestational diabetes, you should be tested for diabetes no later than 12 weeks after your baby is born. If your blood glucose is still high, you may have type 2 diabetes. Even if your blood glucose is normal, you still have a greater chance of developing type 2 diabetes in the future and should get tested every 3 years.

Can other blood glucose tests be used to diagnose type 2 diabetes and prediabetes?

Yes. Health care professionals also use the fasting plasma glucose (FPG) test and the OGTT to diagnose type 2 diabetes and prediabetes. For these blood glucose tests used to diagnose diabetes, you must fast at least 8 hours before you have your blood drawn. If you have symptoms of diabetes, your doctor may use the random plasma glucose test, which doesn’t require fasting. In some cases, health care professionals use the A1C test to help confirm the results of another blood glucose test.

Can the A1C test result in a different diagnosis than the blood glucose tests?

Yes. In some people, a blood glucose test may show diabetes when an A1C test does not. The reverse can also occur—an A1C test may indicate diabetes even though a blood glucose test does not. Because of these differences in test results, health care professionals repeat tests before making a diagnosis.

People with differing test results may be in an early stage of the disease, when blood glucose levels have not risen high enough to show up on every test. In this case, health care professionals may choose to follow the person closely and repeat the test in several months.

Why do diabetes blood test results vary?

Lab test results can vary from day to day and from test to test. This can be a result of the following factors:

Blood glucose levels move up and down

Your results can vary because of natural changes in your blood glucose level. For example, your blood glucose level moves up and down when you eat or exercise. Sickness and stress also can affect your blood glucose test results. A1C tests are less likely to be affected by short-term changes than FPG or OGTT tests.

The following chart shows how multiple blood glucose measurements over 4 days compare with an A1C measurement.

Blood Glucose Measurements Compared with A1C Measurements over 4 Days

Blood glucose (mg/dL) measurements were taken four times per day (fasting or pre-breakfast, pre-lunch, pre-dinner, and bedtime).

The straight black line shows an A1C measurement of 7.0 percent. The blue line shows an example of how blood glucose test results might look from self-monitoring four times a day over a 4-day period.

A1C tests can be affected by changes in red blood cells or hemoglobin

Conditions that change the life span of red blood cells, such as recent blood loss, sickle cell disease, erythropoietin treatment, hemodialysis, or transfusion, can change A1C levels.

A falsely high A1C result can occur in people who are very low in iron; for example, those with iron-deficiency anemia. Other causes of false A1C results include kidney failure or liver disease.

If you’re of African, Mediterranean, or Southeast Asian descent or have family members with sickle cell anemia or a thalassemia, an A1C test can be unreliable for diagnosing or monitoring diabetes and prediabetes. People in these groups may have a different type of hemoglobin, known as a hemoglobin variant, which can interfere with some A1C tests. Most people with a hemoglobin variant have no symptoms and may not know that they carry this type of hemoglobin. Health care professionals may suspect interference—a falsely high or low result—when your A1C and blood glucose test results don’t match.

If you’re of African, Mediterranean, or Southeast Asian descent, you could have a different type of hemoglobin that affects your diabetes care.

Not all A1C tests are unreliable for people with a hemoglobin variant. People with false results from one type of A1C test may need a different type of A1C test to measure their average blood glucose level. The NGSP provides information for health care professionals about which A1C tests are appropriate to use for specific hemoglobin variants.

Read about diabetes blood tests for people of African, Mediterranean, or Southeast Asian descent. The NIDDK has information for health care providers on Sickle Cell Trait & Other Hemoglobinopathies & Diabetes.

Small changes in temperature, equipment, or sample handling

Even when the same blood sample is repeatedly measured in the same lab, the results may vary because of small changes in temperature, equipment, or sample handling. These factors tend to affect glucose measurements—fasting and OGTT—more than the A1C test.

Your health care professional can help you understand your test results.

Health care professionals understand these variations and repeat lab tests for confirmation. Diabetes develops over time, so even with variations in test results, health care professionals can tell when overall blood glucose levels are becoming too high.

How precise is the A1C test?

When repeated, the A1C test result can be slightly higher or lower than the first measurement. This means, for example, an A1C reported as 6.8 percent on one test could be reported in a range from 6.4 to 7.2 percent on a repeat test from the same blood sample.3 In the past, this range was larger but new, stricter quality-control standards mean more precise A1C test results.

Health care professionals can visit www.ngsp.org to find information about the precision of the A1C test used by their lab.

How is the A1C test used after diagnosis of diabetes?

Your health care professional may use the A1C test to set your treatment goals, modify therapy, and monitor your diabetes management.

Experts recommend that people with diabetes have an A1C test at least twice a year.4 Health care professionals may check your A1C more often if you aren’t meeting your treatment goals.4

What A1C goal should I have?

People will have different A1C targets, depending on their diabetes history and their general health. You should discuss your A1C target with your health care professional. Studies have shown that some people with diabetes can reduce the risk of diabetes complications by keeping A1C levels below 7 percent.

Managing blood glucose early in the course of diabetes may provide benefits for many years to come. However, an A1C level that is safe for one person may not be safe for another. For example, keeping an A1C level below 7 percent may not be safe if it leads to problems with hypoglycemia, also called low blood glucose.

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

  • limited life expectancy
  • long-standing diabetes and trouble reaching a lower goal
  • severe hypoglycemia or inability to sense hypoglycemia (also called hypoglycemia unawareness)
  • advanced diabetes complications such as chronic kidney disease, nerve problems, or cardiovascular disease

How does A1C relate to estimated average glucose?

Estimated average glucose (eAG) is calculated from your A1C. Some laboratories report eAG with A1C test results. The eAG number helps you relate your A1C to daily glucose monitoring levels. The eAG calculation converts the A1C percentage to the same units used by home glucose meters—milligrams per deciliter (mg/dL).

The eAG number will not match daily glucose readings because it’s a long-term average—rather than your blood glucose level at a single time, as is measured with a home glucose meter.

Will the A1C test show short-term changes in blood glucose levels?

Large changes in your blood glucose levels over the past month will show up in your A1C test result, but the A1C test doesn’t show sudden, temporary increases or decreases in blood glucose levels. Even though A1C results represent a long-term average, blood glucose levels within the past 30 days have a greater effect on the A1C reading than those in previous months.

Clinical Trials for the A1C Test and Diabetes

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support research into many diseases and conditions.

What are clinical trials and are they right for you?

Clinical trials are part of clinical research and at the heart of all medical advances. Clinical trials look at new ways to prevent, detect, or treat disease. Scientists are conducting research to learn more about diabetes, including studies about A1C. For example

  • how the relationship between A1C and blood glucose may vary in different racial and ethnic groups
  • to find other tests that may be better than A1C for some people
  • to look for ways to further improve A1C test results. Because the A1C value depends on the average life span of your red blood cells, knowing whether the life span of your red blood cells is longer or shorter may give your doctor helpful information.

Researchers also use clinical trials to look at other aspects of care, such as improving the quality of life for people with chronic illnesses. Find out if clinical trials are right for you.

What clinical trials are open?

Clinical trials that are currently open and are recruiting can be viewed at www.ClinicalTrials.gov.


[1] Gillett MJ. International Expert Committee report on the role of the A1C assay in the diagnosis of diabetes. Diabetes Care. 2009;32(7):1327–1334.

[2] American Diabetes Association. 2. Classification and diagnosis of diabetes: Standards of Medical Care in Diabetes—2018. Diabetes Care. 2018;41(suppl 1):S13–S27.

[3] Penttilä I, Penttilä K, Holm P, et al. Methods, units and quality requirements for the analysis of haemoglobin A1c in diabetes mellitus. World Journal of Methodology. 2016;6(2):133–142.

[4] American Diabetes Association. 6. Glycemic targets: Standards of Medical Care in Diabetes—2018. Diabetes Care. 2018;41(suppl 1):S55–S64.

Test, levels, and more for diabetes

The A1C test is a blood test that measures a person’s average blood glucose levels over the past 3 months. Blood glucose is another name for blood sugar.

Doctors use the A1C test to check for:

  • prediabetes
  • type 1 diabetes
  • type 2 diabetes

This test also helps doctors monitor blood glucose levels in people with diagnosed diabetes.

Keeping A1C levels within the normal or target range lowers the risk of developing diabetes or its complications. Read on to learn what A1C test results mean.

The A1C chart below can help a person convert and understand their A1C test results. The doctor can provide more context and describe ways to keep blood glucose levels in a safe range.

The A1C test is also known as the:

  • hemoglobin A1C, or HbA1c, test
  • glycated hemoglobin test
  • glycohemoglobin test

The A1C test measures the percentage of red blood cells that have glucose-coated hemoglobin. This measurement gives doctors an idea of the person’s average blood glucose levels over the past 2–3 months.

Hemoglobin is an iron-rich protein in red blood cells. It helps carry oxygen from the lungs to other tissues.

When glucose enters the blood, it binds to hemoglobin. The more glucose in a person’s bloodstream, the more hemoglobin is bound to glucose.

Undergoing the A1C test is straightforward: A healthcare professional takes a blood sample and sends it to a laboratory for testing.

A doctor may order this test to:

  • diagnose prediabetes
  • diagnose type 1 or type 2 diabetes
  • monitor the blood glucose levels of a person with diabetes to check how well their treatment is working

If a person takes insulin to manage diabetes, their doctor may also ask them to monitor their blood glucose levels at home with a blood glucose meter or continuous glucose monitor.

In this case, the person still needs to undergo regular A1C testing.

Traditionally, A1C levels are reported as a percentage. Alternately, they may be reported as estimated average glucose (eAG), in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L).

Blood glucose meters and continuous glucose monitors also give eAG readings, some from at least 12 days of data.

The A1C test gives a more accurate long-term average. It takes into account fluctuations throughout the day, such as overnight and after meals.

A normal A1C level is below 5.7%. Normal eAG is below 117 mg/dL or 6.5 mmol/L.

If someone’s A1C levels are higher than normal, they may have diabetes or prediabetes. Their doctor might order a repeat test to confirm this.

Target levels in people with diabetes

A doctor will set a person’s target A1C level based on many factors. The right target varies from person to person.

For someone with diabetes, the target A1C level may depend on:

  • the person’s age
  • their overall health
  • whether they are pregnant
  • how long they have had diabetes
  • their prescribed treatment plan
  • any history of adverse effects from the treatment, including episodes of low blood glucose, or hypoglycemia
  • any complications from diabetes
  • the person’s preferences and treatment priorities

In general, a doctor might recommend aiming for A1C levels under 6.5% if a person:

  • is young and has a long life expectancy
  • has had diabetes for a short period
  • is effectively managing their diabetes with lifestyle changes or metformin alone
  • is otherwise in good health

A doctor might recommend A1C targets of 7.0–8.5% if a person:

  • is older and has a shorter life expectancy
  • has had diabetes for a longer period
  • has diabetes that is hard to manage, even with multiple medications
  • has a history of severe hypoglycemia or other adverse effects of treatment
  • has experienced complications of diabetes
  • has other chronic health conditions

A person should work with their doctor to reassess and adjust their A1C targets over time. The condition and treatment goals may change.

To screen for diabetes, a doctor may order an A1C test for someone older than 45. They may also do this for younger people who have other risk factors.

After diagnosing diabetes, a doctor determines how often to test A1C levels.

If a person is meeting their treatment goals, they may need an A1C test twice a year. When managing blood glucose levels is challenging, a person tends to need this test more frequently.

A person should make an appointment with their doctor if they:

  • have questions or concerns about their treatment plan
  • are finding it hard to keep their blood glucose levels within the target range
  • have had symptoms of high or low blood glucose levels
  • think they might have complications of diabetes

Symptoms of high blood glucose levels include:

  • fatigue
  • unusual thirst
  • frequent urination
  • blurred vision

Symptoms of low blood glucose levels include:

  • nervousness, irritability, or anxiety
  • confusion
  • dizziness
  • hunger
  • shaking
  • sweating

Anyone who develops any of the symptoms above or notices other changes in their health should let their doctor know.

A doctor orders an A1C test to check whether someone has prediabetes or type 1 or 2 diabetes. Doctors also use this test to monitor blood glucose levels in people with diabetes to see how well their treatment plan is working.

A1C test results are usually a percentage, but they may come as an eAG measurement. Target A1C levels vary from person to person, depending on age, overall health, and other factors.

Having high A1C levels may indicate that the person has diabetes or a high risk of related complications. In this case, the doctor will work with the person to adjust the approach to treatment.

Understanding Your A1C


The A1C is a blood test that helps determine if your diabetes management plan is working well. (Both Type 1 and Type 2 take this test.) It’s done every 2-3 months to find out what your average blood sugar has been. (You may also hear this test called glycosylated hemoglobin, glycohemoglobin, hemoglobin A1c, and HbA1c.) A1c is the most common name for it though.

How the test works

Essentially, the test can tell how much sugar is in the blood stream by looking for proteins (hemoglobins). When glucose (sugar) enters the blood, it binds to the protein in the red blood cells. This binding creates “glycated hemoglobin”. The more sugar in the blood, the more glycated hemoglobin.

It’s important to test your blood sugar levels (BGLs) throughout the day; however, an A1C test gives you a bigger picture with a long-term average of those blood sugar levels.

What do these numbers mean?

The A1c is an average of what your blood sugar levels have been over the 3-month period. In general, the higher your A1C number, the higher your likelihood of diabetes complications. (You don’t want a high A1C; it means there is too much sugar in your blood and your body isn’t absorbing it.)

A1C number

4.6 – 6.0 Normal (does not have diabetes)
5.7 – 6.4 Pre-diabetes (warning that someone may develop Type 2 or have the beginning onset of Type 1)
6.7+ Diabetes (someone diagnosed with diabetes)
<7.0 – 7.5 Target range (for adults diagnosed with diabetes – children diagnosed with diabetes)

This target range varies between individuals, some people naturally run a little higher, some lower. It is important to note that especially in children a higher A1C (of 7.5) is recommended. The A1C number will help you and your doctor determine though if your diabetes management plan is working well.

Learn more about children’s A1C target range.

Sometimes the test isn’t accurate, and here’s why:

  • If you are bleeding a lot, the protein (hemoglobin) in your red bold cells may be low, so it could say your A1C is lower than it actually is.
  • If you’ve just had a blood transfusion or have other forms of hemolytic anemia, your A1C test results may be lower than it actually is.
  • If you are low in iron in the blood, your A1C test results may be higher than it actually is.
  • If you have a special hemoglobin (variant). Most people have Hemoglobin A. With the variant, you can be falsely high or low. A lab test can be done to see which one you are and special lab tests can then give you an accurate A1C. (Hemoglobin variants are mostly found in black, Mediterranean and Southeast Asian populations.)
  • A new lab can give different results as well. Keep this in mind if your results were sent away to a new facility. It could account for minor reading variations.

A1c number = how much sugar in the blood?

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’s a “perfect A1C”?

This is often said when someone with diabetes has met their A1C target range, (which is 5-7). Keep in mind that an A1C test like any other BGL reading is just information to guide you in your diabetes management. Some run higher while others run low – it really depends on the individual. This number can vary wildly too throughout your life. Consult your doctor to find a target A1C range and a diabetes plan that works for you.

For more Tools + How Tos

What You Should Know About the A1C Test and Diabetes

An estimated 34 million children and adults in the United States have diabetes, while more than twice that—88 million—are living with prediabetes. What’s more, the American Diabetes Association (ADA) reports that another 7.3 million have diabetes, but don’t know it. One key test—the A1C blood test—is critical to diagnosing and managing the disease. Here’s what the test measures, why it’s important, and how monitoring your glucose levels at home can help. 

What is an A1C test? 

The A1C is a common blood test used to diagnose type 1 and type 2 diabetes as well as prediabetes. If you’re living with diabetes, the test is also used to monitor how well you’re managing your blood sugar, or glucose, levels.

The test measures what percentage of hemoglobin proteins in your blood are coated with sugar (glycated) because when glucose builds up, hemoglobin is what it binds to. Hemoglobin is what gives your blood its red color, and its job is to carry oxygen to all of your organs and tissues. 

Since your red blood cells live for about 3 months, the A1C test shows the average level of glucose in your blood from the past 2-3 months. In general, the higher your A1C levels, the poorer your blood sugar control and the higher your risk of diabetes complications. 

In a way, the A1C test captures the bigger picture, like a basketball player’s points-per-game average for the season. It gives you a snapshot into the athlete’s overall success—something that can’t be seen in a single game or from a single day’s blood test results.

What the A1C numbers mean (and what a normal range is)

A1C test results will come back as a percentage—the percent of your red blood cells that have sugar-coated hemoglobin. The higher the percentage, the greater your risk of developing diabetes complications. In addition to helping diagnose diabetes and prediabetes, the test will also give you a baseline A1C level. If you have prediabetes or diabetes, you’ll be tested regularly and can compare those results to your baseline to see how your treatment plan is going. Here’s what your numbers could look like and what they mean: 

A1C test results

If your levels are below 5.7%, that is considered normal. If you land between 5.7% and 6.5%, you fall into the prediabetic category and you’re at a higher risk of developing diabetes. If your test results show you’re above 6.5%, you’re considered in the diabetic range. To confirm a diabetes diagnosis, your healthcare provider will likely look at the results of two blood tests given on different days. The goal A1C for most patients with diabetes is 7% or less, though individual goals may vary depending on the specific circumstances.

Something to keep in mind is that certain factors like pregnancy, kidney and liver disease, certain medications with opioids, some HIV medications, recent or heavy blood loss, or conditions like anemia can all interfere with the accuracy of the A1C test results. These could all influence your A1C goal and are things you can discuss with your healthcare provider ahead of time.

A1IC targets can also change over time as your age or your health condition changes. Generally younger people have a lower A1C goal in order to reduce diabetes-related complications, whereas older people or those with other comorbidities have a higher A1C goal This is why it’s important to work with your doctor to set your own individual A1C goal.

What’s the difference between the A1C test and home glucose monitoring?

If you’re prediabetic or diabetic, you’ll work with your healthcare provider to come up with a treatment plan. A part of your home treatment plan will likely include self-monitoring, which you can do with a blood glucose meter or other device. This will tell you your blood sugar levels at the exact time you do the test—either in milligrams of sugar per deciliter (mg/dL) or millimoles of sugar per liter (mmol/L). 

Blood sugar goes up and down during the day and night, and factors like eating, exercise, or stress, can all affect your blood sugar. So you might see some variability throughout the day in your numbers. To come back to the basketball analogy, these tests can be likened to a single game’s stats and can reveal the daily nuance that the A1C test can’t. 

On the other hand, because the A1C test measures the average blood glucose over the past three months, it provides a good idea of overall glycemic control over time. As we mentioned earlier, it captures the bigger picture. It also doesn’t require fasting, like some blood glucose tests, so it can be given at any time.

The in-the-moment precision of self-monitoring can be helpful when it comes to making choices about your diet and exercise throughout the day. It can also help you keep tabs on your A1C target. For example, if your A1C goal is below 7%—a common target for people with diabetes—you should aim for blood sugar below 154 mg/dL (8.6 mmol/L) on average. The ADA offers a simple A1C calculator where you can easily convert between A1C and eAG. 

Comparison of A1C and eAG meter readings

How often should I get an A1C test?

There’s no one-size-fits-all when it comes to how often you should get tested. The frequency will be determined by your healthcare provider and will depend on a few factors unique to you including your age as well as if you’re on any current diabetes treatment plan with certain goals. 

In general, however, if you have prediabetes, the Mayo Clinic recommends getting tested once a year. If you have diabetes, and if your blood sugar level is consistently within your target range and you don’t use insulin, twice a year is recommended. If your blood sugar levels have been out of your target range and you are using insulin, your doctor might recommend up to four times per year. Additionally, if your diabetes treatment plan changes or you begin taking a new diabetes medication, that could also increase the frequency of A1C testing. You can work with your healthcare provider to decide what works best. 

Whether you’re navigating medications for a recent diagnosis or are looking to learn more about diabetes prevention, we know it can be a lot to sort through. That’s why we’re here to help every step of the way. 

From glucose monitors to test strips to medications, our team of patient care pharmacists at Alto is available to chat whenever questions come up. Feel free to reach out any time via text or phone at 1-800-874-5881, or in-app messaging.

This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition.

Rethinking A1c goals for type 2 diabetes – Harvard Health Blog

“Treat the patient, not the number.” This is a very old and sound medical school teaching. However, when it comes to blood sugar control in diabetes, we have tended to treat the number, thinking that a lower number would equal better health.

Uncontrolled type 2 diabetes (also known as adult-onset diabetes) is associated with all sorts of very bad things: infections, angry nerve endings causing chronic pain, damaged kidneys, vision loss and blindness, blocked arteries causing heart attacks, strokes, and amputations… So of course, it made good sense that the lower the blood sugar, the lower the chances of bad things happening to our patients.

Tracking blood sugar control over time

One easy, accurate way for us to measure a person’s blood sugar over time is the hemoglobin A1c (HbA1c) level, which is basically the amount of sugar stuck to the hemoglobin molecules inside of our blood cells. These cells last for about three months, so, the A1c is thought of as a measure of blood sugars over the prior three months.

Generally, clinical guidelines have recommended an A1c goal of less than 7% for most people (not necessarily including the elderly or very ill), with a lower goal — closer to normal, or under 6.5% — for younger people.

We as doctors were supposed to first encourage diet and exercise, all that good lifestyle change stuff, which is very well studied and shown to decrease blood sugars significantly. But if patients didn’t meet those target A1c levels with diet and exercise alone, then per standard guidelines, the next step was to add medications, starting with pills. If the levels still weren’t at goal, then it was time to start insulin injections.

While all this sounds very orderly and clinically rational, in practice it hasn’t worked very well. I have seen firsthand how enthusiastic attention to the A1c can be helpful as well as harmful for patients.

And so have experts from the Clinical Guidelines Committee of the American College of Physicians, a well-established academic medical organization. They examined findings from four large diabetes studies that included almost 30,000 people, and made four very important (and welcome!) new guidelines around blood sugar control. Here’s the big picture.

Doctors and patients should discuss goals of treatment together and come up with an individual plan

Blood sugar goals should take into account a patient’s life expectancy and general health, as well as personal preferences, and include a frank discussion of the risks, benefits, and costs of medications. This is a big deal because it reflects a change in how we think about blood sugar control. It’s not a simply number to aim for; it’s a discussion. Diabetes medications have many potential side effects, including dangerously low blood sugar (hypoglycemia) and weight gain (insulin can cause substantial weight gain). Yes, uncontrolled blood sugars can lead to very bad things, but patients should get all the information they need to balance the risks and benefits of any blood sugar control plan.

An A1c goal of between 7% and 8% is reasonable and beneficial for most patients with type 2 diabetes…

…though if lifestyle changes can get that number lower, then go for it. For patients who want to live a long and healthy life and try to avoid the complications of diabetes, they will need to keep their blood sugars as normal as possible — that means an A1c under 6.5%. However, studies show that using medications to achieve that goal significantly increases the risk of harmful side effects like hypoglycemia and weight gain. To live longer and healthier and avoid both the complications of diabetes as well as the risks of medications, there’s this amazing thing called lifestyle change. This involves exercise, healthy diet, weight loss, and not smoking. It is very effective. Lifestyle change also can help achieve healthy blood pressure and cholesterol levels, which in turn reduce the risk for heart disease. And heart disease is a serious and common complication of diabetes.

Lifestyle change should be the cornerstone of treatment for type 2 diabetes. The recommendations go on to say that for patients who achieve an A1c below 6.5% with medications, we should decrease or even discontinue those drugs. Doing so requires careful monitoring to ensure that the person stays at the goal set with his or her doctor, which should be no lower than 7%, for the reasons stated above.

We don’t even need to follow the A1c for some patients

Elderly patients, and those with serious medical conditions, will benefit from simply controlling the symptoms they have from high blood sugars, like frequent urination and incontinence, rather than aiming for any particular A1c level. Who would be included in this group? People with a life expectancy of less than 10 years, or those who have advanced forms of dementia, emphysema, or cancer; or end-stage kidney, liver, or heart failure. There is little to no evidence for any meaningful benefit of intervening to achieve a target A1c in these populations; there is plenty of evidence for harm. In particular, diabetes medications can cause low blood sugars, leading to weakness, dizziness, and falls. There is the added consideration that elderly and sick patients often end up on a long list of medications that can (and do) interact, causing even more side effects.

The bottom line

There is no question that type 2 diabetes needs to be taken seriously and treated. But common sense should rule the day. Lifestyle changes are very effective, and the side effects of eating more healthfully and staying more active are positive ones. Every person with type 2 diabetes is an individual. No single goal is right for everyone, and each patient should have a say in how to manage their blood sugars and manage risk. That means an informed discussion, and thoughtful consideration to the number.


Hemoglobin A1c targets for glycemic control with pharmacologic therapy for nonpregnant adults with type 2 diabetes mellitus: A guidance statement update from the American College of Physicians. Annals of Internal Medicine, March 2018.

An overview of the management of diabetes in non-pregnant adults. MGH Primary Care Office Insite, updated June 2016.

Management of persistent hyperglycemia in type 2 diabetes mellitus. UpToDate, updated April 2017.

HBA1C | Haemoglobin A1C | Calculator

The Hb A1c is blood test that provides a method of monitoring a person with diabetes blood sugar levels over the previous 3 months.

The Hb A1c can be used to work out the estimated average glucose (eAG) level using a complex mathematical model.

Enter your Hb A1c to understand what you average blood sugar value has been over the previous 3 months.

How to use the tool:

Enter your Hb A1c value from your last blood test to understand what you average blood sugar value has been over the previous 3 months.

What is Hb A1c test?

The HbA1c test, or the glycated haemoglobin A1c test, is a blood test that can be taken at any time as you don’t need to fast before taking the test. It indicates what your average blood glucose levels are over the past 3 months, by measuring the percentage of blood glucose that has attached to haemoglobin. Haemoglobin is the oxygen carrying protein found in red blood cells.

It is normal for all people to have some glucose attached to haemoglobin. In people with diabetes, the higher the blood glucose levels are, the more glucose you have attached to haemoglobin. A HbA1c level of 6.5% or higher, on two separate tests, can indicate that you have diabetes. Whereas a HbA1c level between 5.7 and 6.4% can indicate prediabetes. Levels below 5.7% are considered normal. In other words, higher A1c percentages indicate an increased risk of diabetes.

The HbA1c test should not be used alone to diagnose diabetes. It should be used in combination with other blood glucose tests.

What does a high Hb A1c reading mean?

There is a strong relationship between high Hb A1c readings and the risk of developing diabetes-related complications.

Why is Hb A1c tested every 3 months?

You Hb A1c is tested every 3 months because our bodies make new red blood cells 3 months.

Your Hb A1c reading from last week won’t be the same as your Hb A1c reading from last year.

estimated Average Glucose

The estimated Average Glucose (eAG) is a way to show patients what their Hb A1c results (shown as a percentage) are using the same units (mg/L or mmol/L) that they’re more familiar with when monitoring their blood glucose levels.

Hb A1c and corresponding estimated average glucose level table

Hb A1c and corresponding estimated average glucose values
Hb A1c % Hb A1c mmol/mol eAG mg/dl eAG mmol/l
5% 31 97 5.4
6% 42 126 7.0
7% 53 154 8.6
8% 64 183 10.2
9% 75 212 11.8
10% 86 240 13.3
11% 97 269 14.9
12% 108 289 16.5

What is a normal Hb A1c reading?

A normal haemoglobin (Hb) A1c level is below 5.7%. Therefore, a healthy Hb A1c value is below 5.7%.

Glycated hemoglobin (HbA1c)

Glycated hemoglobin (A1c) is a specific compound of erythrocyte hemoglobin with glucose, the concentration of which reflects the average blood glucose level over a period of about three months.

Russian synonyms

Glycohemoglobin, hemoglobin A1c, Hb A1c , glycosylated hemoglobin.

English synonyms

Glycated hemoglobin, hemoglobin A1c, HbA1c, glycohemoglobin, glycosylated hemoglobin.

Research method

Ion exchange high performance liquid chromatography (HPLC).


% (percent).

What biomaterial can be used for research?

Venous blood.

How to properly prepare for the study?

  • Do not eat for 2-3 hours before the study, you can drink clean still water.
  • Eliminate physical and emotional stress for 30 minutes before the study.
  • Do not smoke within 30 minutes prior to examination.

General information about the study

The Glycated Hemoglobin (A1c) Test helps you estimate your average blood glucose over the past 2-3 months.

Hemoglobin is an oxygen-carrying protein found inside red blood cells (erythrocytes). There are several types of normal hemoglobin, in addition, many abnormal varieties have been identified, although the predominant form is hemoglobin A, accounting for 95-98% of total hemoglobin.Hemoglobin A is subdivided into several components, one of which is A1c. Part of the glucose circulating in the blood spontaneously binds to hemoglobin, forming the so-called glycated hemoglobin. The higher the concentration of glucose in the blood, the more glycated hemoglobin is formed. Having combined with hemoglobin, glucose remains “in conjunction” with it until the very end of the erythrocyte’s life, that is, 120 days. The combination of glucose with hemoglobin A is called HbA1c or A1c. Glycated hemoglobin is formed in the blood and disappears from it every day, as old red blood cells die, and young (not yet glycated) take their place.

The hemoglobin A1c test is used to monitor the condition of patients diagnosed with diabetes mellitus. It helps to assess how effectively glucose regulation is going on during the course of treatment.

In some patients, a hemoglobin A1c test is prescribed to diagnose diabetes and pre-diabetes in addition to a fasting plasma glucose test and a glucose tolerance test.

The resulting indicator is measured as a percentage.Patients with diabetes should strive to keep their glycated hemoglobin levels below 7%.

A1c should be specified in one of three ways:

  • as a percentage of total hemoglobin,
  • in mmol / mol, according to the International Federation of Clinical Chemistry and Laboratory Medicine,
  • as the average glucose content mg ​​/ dl or mmol / l.

What is the research used for?

  • To control glucose in patients with diabetes mellitus, it is very important for them to maintain its blood level as close to normal as possible.This helps to minimize complications on the kidneys, eyes, cardiovascular and nervous systems.
  • To determine the patient’s average blood glucose over the past several months.
  • To validate diabetes management measures and see if they need adjustments.
  • To determine uncontrolled rises in blood glucose in patients with newly diagnosed diabetes mellitus. Moreover, the test can be prescribed several times until the desired glucose level is detected, then it must be repeated several times a year to make sure that the normal level is maintained.
  • For prophylactic purposes, to diagnose diabetes mellitus at an early stage.

When is the study scheduled?

Depending on the type of diabetes and how well the disease responds to treatment, the A1c test is performed 2 to 4 times a year. On average, patients with diabetes are recommended to be tested for A1c twice a year. If the patient is diagnosed with diabetes for the first time or the control measurement is unsuccessful, the analysis is repeated.

In addition, this test is prescribed if the patient is suspected of diabetes, since there are symptoms of high blood glucose:

  • intense thirst,
  • Frequent, profuse urination,
  • fatigue,
  • blurred vision,
  • Increased susceptibility to infections.

What do the results mean?

Reference values: 4.27 – 6.07%.

The closer the A1c level is to 7% in a patient with diabetes, the easier it is to control the disease.Accordingly, with an increase in the level of glycated hemoglobin, the risk of complications also increases.

The A1c analysis results are interpreted as follows.

Glycated hemoglobin index



The patient has no diabetes

6.5% and more

The patient has diabetes mellitus


Prediabetes (impaired glucose tolerance associated with an increased risk of diabetes)

According to the clinical recommendations of the Ministry of Health of the Russian Federation, Public Association “Russian Association of Endocrinologists” “Algorithms of specialized medical care for patients with diabetes mellitus” (2019.), an additional diagnostic indicator was the average daily plasma glucose (SSGP) for the last three months and its correlation with the HbA1c level.

What can influence the result?

In patients with abnormal forms of hemoglobin, for example, in patients with sickle-shaped erythrocytes, the level of glycated hemoglobin will be underestimated. In addition, if a person suffers from anemia, severe bleeding, his test results may also be underestimated. On the contrary, A1c values ​​are overestimated with a lack of iron and with a recent blood transfusion (since liquid blood preservatives contain a high concentration of glucose).

Download an example of the result

Important notes

Analysis for A1c does not reflect sharp changes in blood glucose. Fluctuations in glucose in patients with labile diabetes will also not be detected by this test.

Also recommended

Who orders the study?

Therapist, endocrinologist.

90,000 Blood test for glycated hemoglobin – will help to identify diabetes in the early stages!

Blood test for glycated hemoglobin – will help to identify diabetes in the early stages!

Glycated or glycosylated hemoglobin is the most important indicator of a biochemical nature, showing the level of sugar in the blood for a certain period.In general, this is a complex consisting of hemoglobin and glucose, which are irreversibly combined, which is a sign of diabetes mellitus. With the help of an analysis for glycated hemoglobin in the blood, diabetes can be detected in the early stages, and this helps to start timely and adequate treatment, which will definitely give positive results to improve the patient’s condition.

Glycosylated hemoglobin is present in any blood: both in healthy people and in those with diabetes mellitus.But a significant difference lies in the fact that in a patient with diabetes mellitus, his norm is significantly exceeded and this becomes the reason for the further development of diabetes mellitus and all serious complications against its background.

Benefits of glycated hemoglobin analysis:

  • It can be done at any time, regardless of whether you have a heavy meal or on an empty stomach;
  • It more effectively and accurately allows you to detect diabetes mellitus in the early stages;
  • The analysis is much easier and faster than other analyzes;
  • Helps doctors understand whether a person with diabetes mellitus has accurately controlled his blood sugar level in the last 3 months;
  • The quality and accuracy of the analysis are not affected by other factors (infectious, viral and colds).

First of all, this analysis allows not only to identify the already begun early stages of the development of diabetes mellitus, but even show whether a person has a predisposition to the disease of diabetes mellitus. Prevention measures to prevent the risk of developing diabetes mellitus graze a person’s life, allow him to live a normal life.

The second important aspect of the analysis is the ability to understand how attentive the patient is to his health, whether he is able to compensate for the level of sugar in the blood and keep it in the norm necessary for his life for a long time.

But even healthy people, it is advisable to do this analysis at least once a year in order to prevent the risk of developing diabetes mellitus or to detect diseases in the early stages.

This analysis is done at any time, regardless of whether blood is taken on an empty stomach or after a meal. You can also conduct this research at the moment when you are taking various drugs that lower sugar, drugs for other diseases.

For those who have already been diagnosed with diabetes mellitus, the analysis is recommended depending on how well the diabetes is compensated.

General recommendations for analyzes for glycated hemoglobin:

  1. If the HbA1C indicator is lower than 5.7% (there is no disease and the risk of its development is minimal), you can take tests once every few years;
  2. With sufficient control of diabetes mellitus and the indicator of glycated hemoglobin not higher than HbA1C 7%, it is necessary to do the analysis 1 time in 6 months;

When changing treatment methods or diabetes mellitus and a short medical history, it is recommended to carry out an analysis every 3 months.

How to get tested for glycated hemoglobin

Capillary blood is taken to test for glycated hemoglobin. Although there are no contraindications as to whether on an empty stomach or after a meal, it is better to do the analysis in the morning on an empty stomach, without prior physical exertion. Based on the results of the analyzes, it is possible to draw appropriate conclusions about the human condition.

The results of analyzes for glycated hemoglobin show:

  • When HbA1C is less than 5.7% there is no risk of developing diabetes mellitus and carbohydrate metabolism is normal;
  • With HbA1C, which is from 5.7 to 6.0%, the disease is not yet present, but the person is at risk;
  • With HbA1C, which is from 6.1 to 6.4%, the disease is also not yet present, but the degree of risk is already defined as quite high and a person is recommended to already review his diet and apply a special diet low in light carbohydrates, start an active lifestyle and engage in physical activities loads;
  • When HbA1C is greater than or equal to 6.5%, the doctor diagnoses preliminary diabetes and additional laboratory tests are needed to obtain a refutation or confirmation of the disease.
  • It is important to know: the lower the glycated hemoglobin index in a patient with diabetes mellitus, the more thoroughly he compensated for it during the previous 3 months. As a rule, the indicator should vary between 5 and 7%.
  • Regular analysis helps not only to inhibit the further development of diabetes mellitus, but even to significantly reduce the risk of developing complications associated with diabetes mellitus, which is very important for the patient.
  • It is important to know: a decrease in the HbA1C indicator even by 1% is an extension of the life of a person suffering from diabetes mellitus by several more years!
  • The main goal of all therapy for a patient with diabetes mellitus is to achieve a normal HbA1C level, which should be less than or equal to 7%. If this goal is achieved, it is safe to say that diabetes mellitus is well compensated and the risks of developing various complications are minimized.
    Of course, it is best to achieve an HbA1C score that is present in healthy people and is no more than 4.6% and it is precisely for this indicator that a patient with diabetes should always strive.
  • It is important to know: such indicators of glycated hemoglobin as 4.6% can be achieved with any type of diabetes mellitus, for this it is necessary to follow a diet and lead a healthy, active lifestyle with the necessary physical activity.
  • You can simplify your life and get the right level of glycated hemoglobin even without the help of drugs that lower the amount of sugar: a diet low in carbohydrates will make it possible to inject less insulin, which means that the risk of developing hypoglycemia will also decrease.
  • After testing for glycated hemoglobin, the HbA1C indicator in the elderly should be no more than 8%, it is better when it is 7.5%.
  • The HbA1C indicator in children, adolescents, pregnant women should be less than 6.5%, and ideally even lower than 5.%.
  • The glycated hemoglobin test is vital and very important. A large percentage of patients with diabetes mellitus die due to the development of cardiovascular complications and stroke, kidney failure and other diseases.To prevent such complications and live a fairly long life, it is necessary to control not only blood sugar levels, but also to undergo regular tests for glycated hemoglobin.
  • Many people with diabetes make one terrible mistake when they think that the analysis for glycated hemoglobin and positive data allows you not to self-monitor blood sugar levels.
  • Based on the above, it is always necessary to evaluate the HbA1C indicator when conducting self-control and obtaining its results, which will help to understand how and with what dynamics the disease progresses.
    • Observe the special type of food and regime.
    • Actively engage in physical education.
    • Take medication or insulin on time.
    • Observe sleep and wakefulness.
    • Watch your home glucose more often.
    • Be on time for your appointment.
      • HbA1c should be determined once every three months. After evaluating the result, take appropriate measures.
      • Determination of HbA1c does not in any way replace the measurement of blood glucose with a conventional glucometer.
      • Even if you have ideal HbA1c, but there are daily fluctuations in blood sugar of more than 5 mmol / L, this can in no way protect you from developing complications. It has been proven that with the same indicator, those who have had or have such fluctuations are most susceptible to complications.
      • Long-term elevated levels of HbA1c should be reduced gradually, by 1% per year.
      • Do not chase the ideal, strive for your target. What is given to the young, the elderly can be harmful.

to the content How and how to reduce glycated hemoglobin A decrease in glycated hemoglobin is inextricably linked with a decrease in blood glucose levels. Therefore, in order to reduce the level of HbA1c, it is necessary to follow all the recommendations of the doctor for the treatment of diabetes, namely:

If you see that from all your efforts, your glucose level returns to normal throughout the day and you feel better, then you are on the right track and then the next blood test will please you well.

Summary of glycated hemoglobin:

In total:

Lead a healthy lifestyle, because the causes of diabetes mellitus are most often rooted in unhealthy diet.

If a doctor has diagnosed diabetes, diet alone is no longer enough. In this case, you will be assigned additional examinations and recommended treatment. If you follow all the recommendations of a specialist, you can live a full life for many years, regularly monitoring blood sugar levels.

Clinical doctor

laboratory diagnostics Elena Shishkina

90,000 What is glycated hemoglobin and what is its rate

Many people do not know why they donate glycated hemoglobin. In fact, it is an important indicator that can be used to track the development of diabetes mellitus. By this coefficient, it is easy to detect the disease at the earliest stages, and begin treatment.

What is glycated hemoglobin?

Often, even people with diabetes do not know what this glycated hemoglobin is. Everything is very simple. When a person consumes carbohydrates, sugars enter the bloodstream. They pass through the erythrocyte membrane. Their amino acids react with sugars to form glycated hemoglobin. The compound is very stable, its concentration is maintained for 120 days, after which the erythrocytes are destroyed.

All people have glycated hemoglobin.The difference between healthy people and people with diabetes is only in its concentration. This indicator reflects how correctly the processes of carbohydrate metabolism are going on in the body. If there are malfunctions and the sugar level is increased, then the indicator will be more than normal.

These numbers can be used to detect latent diabetes, because the parameter displays the sugar level not at a specific moment when it is easy to lower it, but for 3 months. It is important during treatment to monitor the patient’s condition.

Therefore, every person should know what glycated hemoglobin is in a blood test, especially those who are already at risk or have diabetes.

How to donate blood for glycated hemoglobin correctly?

The analysis for glycated hemoglobin does not require any specific preparation. He is handed over in the morning, blood is taken from a vein. Diseases of the thyroid gland, systematic intake of vitamins, anemia can affect the results.

Eaten food does not distort the result, just like alcohol, stress the day before, SARS and flu.

What is the rate of glycated hemoglobin?

In order not to worsen your condition, you need to know not only what glycated hemoglobin in the blood means, but also know your norm.

Indicator depends on age:

  1. For adolescents and people under 30, an indicator that does not exceed 6.5% is considered the norm.
  2. In the middle age (from 30 to 50 years), the parameter should not exceed 7%.
  3. For elderly people who are over 60 years old, an increase of up to 7.5% is permissible, but no more.

In a healthy child, the indicator is the same as in adults. Its normal range is 4.5 to 6%. If deviations from these norms are found, it is necessary to additionally undergo an examination to establish why the blood sugar level is elevated.Usually, at rates of 6.1-6.4% (doctors call this condition prediabetes), health control needs to be strengthened.

If there is no suspicion of diabetes, then it is enough to undergo such a check once every 2-3 years. If the indicator is fixed at an increased level, this means that the check must be passed every year. Depending on the development of the disease, the doctor may recommend that the patient with diabetes be tested every 3 or 6 months.

What is the norm for diabetics?

For doctors, the glycated hemoglobin count can say a lot.Determination of its level provides a more thorough control of sugar and correction of diet, treatment regimen, dosage of drugs. For those diagnosed with diabetes, a level of less than 8% is normal. A parameter higher than this value indicates the possibility of serious complications. But you can’t lower it too sharply, it will only get worse, because the body is already accustomed to high glucose concentrations.

At a young age, you need to strive to keep it within 6.5-7%, on average from 7 to 7.5%, after 50, make sure that the indicator is not higher than 7.5-8%.

How to lower the level of glycated hemoglobin?

It should be remembered what glycated hemoglobin determines in order to bring these numbers back to normal. It shows the average glucose level over 3 months, and not at a specific point in time. Therefore, this indicator at home can be reduced only by reducing excess weight and improving metabolism.

And for this you need:

  1. Eat right. The diet should contain less fatty and fried foods.The dosage of fresh fruits and vegetables should be increased. Legumes, bananas, low-fat dairy products, lean fish, and nuts are useful.
  2. Go in for sports. Physical activity should take at least 30 minutes per day. This will optimize weight and protect the heart from complications.
  3. Deal with stress. Any shock negatively affects the metabolism and heart. Therefore, stress must be dealt with with the help of breathing exercises, meditation.

Knowing what glycated hemoglobin shows in a blood test, you can monitor your health and well-being.This applies to both healthy people and diabetics.

90,000 New method for monitoring diabetes in early stages

A new method for monitoring diabetes in the early stages

1,5-Anhydroglucitol (1,5-AG, 1-deoxy-D-glucose) is a natural monosaccharide. It was proposed to use the value of the level of 1.5-AG in plasma to assess postprandial glycemia: it decreases with hyperglycemia above 9.99 mmol / L and responds quickly to changes in blood glucose levels – it returns to normal after about 2 weeks in the absence of hyperglycemia.Monitoring 1,5-AG in people with diabetes mellitus (DM) of any type (1 or 2) can help in determining how often their blood glucose levels exceed 9.99 mmol / L, even in the presence of a relatively “good” glycated hemoglobin (HbA1c) or blood glucose when monitored.

Clinical outcome data are currently not available using this method of glycemic control. But recent studies ( Elizabeth Selvin, Andreea M. Rawlings, Morgan Grams, Ronald Klein, Michael Steffes, Josef Coresh.Association of 1,5-Anhydroglucitol with Diabetes and Microvascular Conditions. American Association for Clinical Chemistry 2014. ) reported an association of 1.5-AG with long-term prognosis of the risk of microvascular outcomes, especially in people with diabetes, even after adjusting for HbA1c levels. The authors established a relationship between the level of 1.5-AG and the incidence of retinopathy, mainly due to a strong correlation in persons with diagnosed diabetes: odds ratio (OR) 11.26 (95% CI 6.17-20.53) for 1.5-AG <6 μg / ml compared to 1.5-AG ≥10 μg / ml.This result remained significant after additional adjustment for Hb A1c (OR 4.85, 95% CI 2.42-9.74). In individuals with diabetes, low levels of 1.5-AG (<6 μg / ml vs ≥10 μg / ml) were also associated with a more than 2-fold increase in the risk of chronic kidney disease [adjusted hazard ratio (RR) 2.83; 95% CI 2.15-3.74]. Participants in the non-diabetic study with a high 1.5-AG value (≥10 μg / mL) had low rates of retinopathy and a low risk of kidney disease. In individuals without diagnosed diabetes at baseline, 1.5-AG <10 μg / mL was also associated with incidence of diabetes in the next 20 years (adjusted HR, 2.29, 95% CI, 2.03-2.58).

Thus, the 1,5-anhydroglucitol (1,5-AG, 1-deoxy-D-glucose) test is designed to detect glycemic variability in people with diabetes who have normal or near-normal A1c (HbA1c) levels.

Ordering information:

Cat. No .: CEB046Ge “Kit for the immunoassay for the determination of 1,5-anhydroglucitol” 96 tests

Blood test for glycated hemoglobin

  • Doctors
  • Updated: 18 June 2020

Diabetes mellitus is a disease from which no one can consider himself protected, even if the diagnosis has not yet been made.

Diabetes mellitus is a disease from which no one has the right to consider himself protected, even if the diagnosis has not yet been made. According to the International Diabetes Federation for 2015, there are 415 million diabetics in the world. There are 12 million of them in Russia, according to some sources – 17, that is, every tenth. By 2040, the number of patients is expected to increase by one and a half times. Each of us can be among them.

Symptoms of diabetes mellitus

If you have any suspicions, you have noticed three alarming symptoms – “three Ps” ( polydipsia – unnaturally strong thirst, polyphagia – unquenchable hunger and polyuria – excretion of more than 2 liters in urine per day), think about it, do not Is it time to see a doctor.


The most accurate control method available to us is the analysis for glycated hemoglobin . It does not require preparation, and this test is more reliable than determining the level of sugar in the blood.

What is glycated hemoglobin?

Glycated, or glycosylated, is the hemoglobin associated with glucose (abbreviated as “glycohemoglobin”). As you know, hemoglobin is contained in red blood cells – erythrocytes. Sugars penetrate the erythrocyte membrane and interact with hemoglobin to produce glycohemoglobin.In contrast to the level of free glucose unbound with hemoglobin, the level of glycated hemoglobin in the blood remains relatively constant, because normally hemoglobin inside red blood cells is stable. After working for 4 months on the transportation of oxygen and carbon dioxide, erythrocytes are destroyed in the red pulp of the spleen. Their hemoglobin and glycohemoglobin break down in the spleen and liver. The end product of the breakdown of hemoglobin – bilirubin – does not bind to sugar.

Just because red blood cells live for 4 months, the level of glycohemoglobin remains constant for 120 days.It is not affected by the time of day, physical activity, food intake, emotional state.

What does this indicator say?

The content of glycated hemoglobin is proportional to the content of sugar in the blood – glycemia. The higher its level, the more hemoglobin will bind to glucose and the more the level of glycated hemoglobin will rise. For both diabetics and those who are not sick, an increase in glycohemoglobin levels is a reason to see a doctor. Patients are prescribed therapy or are advised to change their lifestyle on time.To prevent the disease, a low-carb diet is prescribed.

Correspondence between glycated hemoglobin (HbA1C) and average blood glucose levels for 3 months

HbA1C,% Glucose, mmol / l What does it mean
4 3.8 The metabolism of carbohydrates is normal, the risk of diabetes is minimal
4.5 4.6
5 5.4
5.5-5.7 6.5
5.7-6.0 6.5-7.0 Increased risk of diabetes.It is advisable to limit the use of sweets and consult an endocrinologist.
6.1-6.4 7.0-7.8 High risk of diabetes. It is necessary to consult an endocrinologist.
6.5 and more 7.9 and more The diagnosis of diabetes mellitus is preliminary. Additional tests are needed to confirm or refute.

Disadvantages of the indicator

The only vulnerability of the method is the case when manipulations are performed with the patient’s blood.Blood transfusions distort the picture because the glycosylated hemoglobin values ​​of the donor and recipient differ. But this also manifests itself during normal work with the meter. Bleeding or hemolysis (destruction of red blood cells) causes a false decrease in the result, and expect a false increase in iron deficiency anemia.

Purpose of method

The analysis for glycated hemoglobin will resolve the doubts of those whose blood glucose levels are on the verge of normal, and will show the true picture if the patient has not adhered to the diet for the last 3-4 months, and a week before the next tests, he stopped eating sweets in the hope that no one will find out about his non-compliance with the doctor’s recommendations.

Measuring frequency

If the diagnosis has already been made, then contacting a specialist will help you find out how often it is better to take an analysis to control the treatment. In the absence of complaints, the timing of the visit to the endocrinologist is determined by the doctor. The life span of an erythrocyte sets the frequency of analysis with which you need to donate blood – 3 times a year. In the absence of both complaints and negative dynamics, it is not necessary to consult an endocrinologist more often.

Alina Petyaeva

Glycosylated hemoglobin HbA1c | Nikolab

Glycosylated hemoglobin HbA1c

Glycosylated hemoglobin HbA1c – an analysis that is used to identify the chemical compound of hemoglobin (which is contained in red blood cells) with glucose.The analysis shows the average blood glucose value over the past three months.

Blood glucose binds with hemoglobin to form a stable compound – glycosylated hemoglobin. Hemoglobin A, one of several normal types of this protein, accounts for 95% to 98% of all hemoglobin in the body. The more glucose in the blood, the higher the glycosylated hemoglobin HbA1c.

You can find various names for this indicator:

  • A1c
  • Glycated hemoglobin
  • Glycosylated hemoglobin
  • Hemoglobin A1C

Indications for appointment

An appointment for the analysis of glycosylated hemoglobin HbA1c can be prescribed by a physician or endocrinologist.The analysis is prescribed for people with suspected diabetes, namely those who have one of the following indicators:

  • intense thirst,
  • Frequent, profuse urination,
  • fatigue,
  • blurred vision,
  • Increased susceptibility to infections.

In addition, this analysis evaluates the effectiveness of treatment and its adjustment (if necessary) in order to prevent diabetes.

Patients with diabetes mellitus undergo this analysis 2 times a year, and in case of severe course – 4 times a year.

Reference values ​​(laboratory standards)

Capillary or venous blood is taken to test for glycated hemoglobin.

The American Diabetes Association recommends that HbA1C levels be 7% or lower, and the closer to 6% with no health risk, the better.

This laboratory test is widely used to assess the degree of compensation of diabetes mellitus:

  • glycated hemoglobin level within 4.8-6.0% indicates good diabetes compensation in the last 1-1.5 months,
  • 6.0-8.9% – about disease subcompensation,
  • more than 9.0% – about decompensation and the need to adjust antidiabetic therapy.

In addition, this test is performed on pregnant women for pregnancy diabetes.

It is important to know: a decrease in the HbA1C indicator even by 1% is an extension of the life of a person suffering from diabetes mellitus for several more years!

The HbA1C indicator in children, adolescents, pregnant women should be less than 6.5%, and ideally even lower than 5.%.

Increase in indicator

High doses of aspirin and chronic use of opiates can increase glycosylated hemoglobin HbA1c. Also, an overestimated figure occurs with a lack of iron and with a recent blood transfusion.

Decrease in indicator

A decrease in the level of glycated hemoglobin is associated with a decrease in the level of glucose in the blood.

Iron supplements, vitamins B12, C, E, aspirin and antiretroviral drugs can lower the level of glycosylated hemoglobin HbA1c.

Glycated hemoglobin – Glycated hemoglobin

Chemical compound

Glycated hemoglobin ( glycohemoglobin , HbA1c , Hemoglobin A1c , A1c or, less often, HbA 1c , . a form of hemoglobin (Hb) that is chemically bound to sugar. Most monosaccharides, including glucose, galactose, and fructose, spontaneously (i.e.i.e., non-enzymatic) bind to hemoglobin when they are present in a person’s bloodstream. However, glucose is less likely to do this than galactose and fructose (13% fructose and 21% galactose), which may explain why glucose is used as the main metabolic fuel in humans.

Formation of a sugar-hemoglobin bond indicates the presence of excess sugar in the bloodstream, often indicative of diabetes. A1C is of particular interest because it is easy to spot.The process of attaching sugars to hemoglobin is called glycation. HbA 1c is a measure of the beta-N-1-deoxyfructosyl component of hemoglobin.

A1c is measured primarily to determine the three-month average blood sugar level and can be used as a diagnostic test for diabetes mellitus and as an assessment test for glycemic control in people with diabetes. The test is limited to a three-month average because the average lifespan of a red blood cell is four months.Since individual red blood cells have different life spans, the test is used as a limited indicator – three months. Normal glucose levels produce normal amounts of glycated hemoglobin. As the average amount of plasma glucose increases, the proportion of glycated hemoglobin increases in a predictable manner. In diabetes, higher amounts of glycated hemoglobin, indicating poor blood glucose control, have been associated with cardiovascular disease, nephropathy, neuropathy, and retinopathy.


Glycated hemoglobin is preferred over glycosylated hemoglobin to reflect the correct (non-enzymatic) process. The early literature often used glycosylation , as it was unclear which process was involved until further research was undertaken. These terms are still sometimes used interchangeably in English literature.

The name HbA 1c comes from type A hemoglobin, which is separated by cation exchange chromatography.The first fraction to be separated, probably considered pure hemoglobin A, was designated HbA 0 , and the next fractions were designated HbA 1a , HbA 1b and HbA 1c in the order of their elution. Improved separation techniques subsequently led to the separation of more subfractions.


Hemoglobin A1c was first separated from other forms of hemoglobin by Huisman and Meyering in 1958 using a chromatographic column.It was first characterized as a Bookchin and Gallop glycoprotein in 1968. Its increase in diabetes was first described in 1969 by Samuel Rahbar et al. The reactions that led to his formation were characterized by Bunn and his collaborators in 1975.

The use of hemoglobin A1c to monitor the degree of control of glucose metabolism in diabetic patients was proposed in 1976 by Anthony Keramy, Ronald Koenig, et al.

Mechanisms of damage

Glycated hemoglobin causes an increase in the amount of highly active free radicals inside blood cells.Radicals change the properties of blood cell membranes. This leads to aggregation of blood cells and an increase in blood viscosity, which leads to impaired blood flow.

Another way to damage glycated hemoglobin is inflammation, which leads to the formation of atherosclerotic plaques (atheroma). Free radical buildup promotes excitation from Fe 2+ -hemoglobin through Fe 3+ -Hb in the abnormal FERRYL of hemoglobin (Fe 4+ -Hb).Fe 4+ is unstable and reacts with specific amino acids in hemoglobin to restore its oxidation state Fe 3+ . Hemoglobin molecules stick together through cross-linking reactions, and these hemoglobin clots (multimers) damage cells and release Fe 4+ hemoglobin into the matrix of the innermost layers (subendothelium) of arteries and veins. This leads to increased permeability of the inner surface (endothelium) of blood vessels and the production of pro-inflammatory monocyte adhesion proteins, which promote the accumulation of macrophages on the surface of blood vessels, ultimately leading to the formation of harmful plaques in these vessels.

Highly glycated Hb-AGEs pass through the vascular smooth muscle layer and inactivate acetylcholine-induced endothelium-dependent relaxation, possibly by binding to nitric oxide (NO), interfering with its normal functioning. NO is a potent vasodilator and also inhibits the formation of the oxidized form of LDL, which promotes plaque formation (ie, “bad cholesterol”).

This general degradation of blood cells also releases heme from them.Free heme can cause oxidation of endothelial and LDL proteins, leading to plaque formation.

The glycation pathway is through the Amadori rearrangement (in HbA1c, R is usually the N-terminal valine).

Principle in Medical Diagnostics

Protein glycation is common, but in the case of hemoglobin, a non-enzymatic condensation reaction occurs between glucose and the N-terminus of the beta chain. This reaction gives a Schiff base (RN = CHR ‘, R = beta chain, CHR’ = derivative of glucose), which itself converts to 1-deoxyfructose.This second transformation is an example of the Amadori rearrangement. When blood glucose levels are high, glucose molecules attach to hemoglobin in red blood cells. The longer blood hyperglycemia is observed, the more glucose binds to hemoglobin in red blood cells and the higher the level of glycosylated hemoglobin.

After glycation, the hemoglobin molecule remains the same. Thus, the accumulation of glycated hemoglobin in the erythrocyte reflects the average glucose level to which the cell is exposed during its life cycle.Measurement of glycated hemoglobin allows the effectiveness of therapy to be assessed by monitoring the long-term regulation of serum glucose.

A1c is the weighted average blood glucose level over the lifetime of the red blood cells (117 days for men and 106 days for women). Consequently, glucose levels on days close to the test contribute significantly more to A1c than levels on days after the test.

This is also supported by clinical practice data showing that HbA1c levels improved significantly 20 days after initiation or intensification of glucose-lowering treatment.


Several methods are used to measure hemoglobin A1c. Laboratories can use high performance liquid chromatography, immunoassay, enzymatic analysis, capillary electrophoresis, or boronate affinity chromatography. In devices for the provision of medical care (for example, in a doctor’s office), boronate-based enzyme immunoassay chromatography is used.

In the United States, HbA testing laboratories 1c are certified by the National Glycohemoglobin Standardization Program to standardize them in the 1993 DCCT Study.An additional percentage scale, Mono S was previously used in Sweden and KO500 in Japan.

Change to IFCC units

The American Diabetes Association, the European Association for the Study of Diabetes and the International Diabetes Federation have agreed that in the future, HbA 1c should be registered with the divisions of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). IFCC reporting was introduced in Europe, with the exception of the UK, in 2003; The UK has been double reporting since June 1, 2009.until October 1, 2011

Conversion between DCCT and IFCC is performed using the following equation:

i FCC HOUR B A 1 c mmol mol = [DCC T HOUR B A 1 c (%) – 2.14] × 10.929 {\ displaystyle \ mathrm {IFCC} \, \ mathrm {HBA1c} \, {\ frac {\ text {mmol}} {\ text {mol}}} = [\ mathrm {DCCT} \, \ mathrm {HBA1c} \, (\%) – 2.14] \ times 10.929}
IFCC-HbA 1c DCCT-HbA 1c Mono S- HbA 1c
(mmol / mol) (%) (%)
10 3.1 2.0
20 4.0 2.9
30 4.9 3.9
40 5.8 4.8
45 6.3 5.3
50 6.7 5.8
55 7.2 6.3
60 7.6 6.8
65 8.1 7.2
70 8.6 7.7
80 9.5 8.7
90 10.4 9.6
100 11.3 10.6

Interpretation of results

Laboratory results may vary based on analytical technique, subject age, and biological differences between individuals.Higher levels of HbA 1c are found in people with persistently elevated blood sugar, such as diabetes. Although treatment goals for diabetic patients differ, many include a target range for HbA values ​​of -1c . In a diabetic with good glucose control, the HbA 1c level is close or within the normal range.

The International Diabetes Federation and the American College of Endocrinology recommend HbA values ​​of 1c below 48 mmol / mol (6.5 DCCT%), while the American Diabetes Association recommends HbA 1c below 53 mmol / mol for most patients (7, 0 DCCT%).Recent results from large studies indicate that a target below 53 mmol / mol (7 DCCT%) for older people with type 2 diabetes may be overwhelming: below 53 mmol / mol, the health benefits of a reduced A1c are reduced and intense glycemic control is required for reaching this level, leads to an increase in the frequency of dangerous episodes of hypoglycemia.

A retrospective study of 47,970 patients with type 2 diabetes aged 50 years and older showed that patients with HbA 1c more than 48 mmol / mol (6.5 DCCT%) had an increased mortality rate, but a later international study refuted these results …

UKPDS Review, Action to Control Cardiovascular Risk in Diabetes (ACCORD), ADVANCE and Veterans Diabetes Research (VADT) have assessed the risks of major complications of diabetes (diabetic retinopathy, diabetic nephropathy, diabetic neuropathy and macrovascular disease) are reduced by about 3% for each 1 mmol / mol HbA reduction 1c .

However, the ACCORD study, designed specifically to determine whether lowering HbA 1c below 6.0% with increased amounts of drugs, the incidence of cardiovascular events, showed higher mortality with this intensive therapy, so much so that the trial was discontinued 17 months earlier.

When setting an HbA target of 1c , clinicians should consider the health of patients, their risk of hypoglycemia, and their specific health risks. Since patients have a responsibility to prevent or respond to their episodes of hypoglycemia, their input and physicians’ assessment of the patient’s self-help skills is also important.

A persistent increase in blood sugar (and therefore HbA 1c ) increases the risk of long-term vascular complications of diabetes such as coronary artery disease, heart attack, stroke, heart failure, renal failure, blindness, erectile dysfunction, neuropathy (loss of sensation especially in the feet), gangrene and gastroparesis (delayed gastric emptying).Poor blood glucose control also increases the risk of short-term complications from surgery, such as poor wound healing.

Lower-than-expected HbA levels 1c can be seen in people with reduced erythrocyte life, such as glucose-6-phosphate dehydrogenase deficiency, sickle cell anemia, or any other condition that causes premature red blood cell death. Donating blood will lead to the rapid replacement of lost red blood cells by newly formed red blood cells.Since these new red blood cells will only exist for a short period of time, their presence will lead to an underestimation of the real average HbA levels 1c . There may also be distortions from a blood donation that occurred two months earlier due to abnormal timing of the erythrocyte age, resulting in an older than normal average life of blood cells (resulting in an overestimation of the actual average blood glucose level. levels). Conversely, higher than expected levels can be seen in people with longer erythrocyte lifespan, such as deficiencies in vitamin B 12 or folate.

Results may be unreliable in many cases, such as after blood loss, surgery, blood transfusion, anemia, or high red blood cell turnover; in the presence of chronic kidney or liver disease; after taking high doses of vitamin C; or treatment with erythropoietin. In general, the reference range (which occurs in healthy young adults) is around 30–33 mmol / mol (4.9–5.2% DCCT). Average HbA 1c for type 1 diabetics in Sweden in 2014was 63 mmol / mol (7.9 DCCT%), and for type 2 – 61 mmol / mol (7.7 DCCT%).

An approximate comparison between the HbA values ​​of 1c, in percent DCCT (%), and eAG (Calculated Mean Glucose) measurements is given by the following equation:

eAG (mg / dL) = 28.7 × A1C – 46.7
eAG (mmol / L) = 1.59 × A1C – 2.59
Data in parentheses represent 95% confidence intervals
HbA 1c eAG
% mmol / mol mmol / l mg / dl
5 31 years 5.4 (4.2-6.7) 97 (76-120)
6 42 7.0 (5.5-8.5) 126 (100-152)
7 53 8.6 (6.8-10.3) 154 (123-185)
8 64 10.2 (8.1-12.1) 183 (147-217)
9 75 11.8 (9.4-13.9) 212 (170-249)
10 86 13.4 (10.7-15.7) 240 (193-282)
11 97 14.9 (12.0-17.5) 269 (217-314)
12 108 16.5 (13.3-19.3) 298 (240-347)
13 119 18.1 (15-21) 326 (260-380)
14 130 19.7 (16-23) 355 (290-410)
15 140 21.3 (17-25) 384 (310-440)
16 151 22.9 (19-26) 413 (330-480)
17 162 24.5 (20-28) 441 (460-510)
18 173 26.1 (21-30) 470 (380-540)
19 184 27.7 (23-32) 499 (410-570)

Normal, pre-diabetic and diabetic range

American Diabetes Association 2010 Standards of Care for Diabetesadded = HbA 1c ≥ 48 mmol / mol (≥ 6.5 DCCT%) as another criterion for the diagnosis of diabetes.

HbA1C Diagnostic Standard for Diabetes
HbA1C Diagnostics
<5.7% Normal
5.7-6.4% Prediabetes
> 6.5% Diabetes mellitus

Indications and Usage

The glycated hemoglobin test is recommended both for checking blood sugar levels in people with prediabetes and for monitoring blood sugar levels in patients with more elevated levels, so-called diabetes mellitus.For a single blood sample, it provides much more informative information about glycemic behavior than fasting blood sugar. However, fasting blood sugar tests are extremely important when deciding on treatment. The American Diabetes Association guidelines are similar to others in that they recommend testing for glycated hemoglobin at least twice a year in diabetic patients who achieve treatment goals (and who have stable glycemic control) and quarterly in diabetic patients whose treatment has changed.or who are not meeting glycemic goals.

Glycated hemoglobin measurement is not suitable if diet or treatment changes have been made within 6 weeks. Similarly, the test assumes normal RBC aging and a combination of hemoglobin subtypes (predominantly HbA in healthy adults). Therefore, people with recent blood loss, hemolytic anemia, or genetic differences in the hemoglobin molecule (hemoglobinopathy), such as sickle cell disease and other conditions, or who have recently donated blood, are not eligible for this test.

Due to the variability of glycated hemoglobin (as shown in the table above), patients should be tested for additional measures when or near recommended targets. Individuals with HbA 1c values ​​of 64 mmol / mol or less should be provided with additional testing to determine if HbA 1c values ​​are associated with averaging high blood glucose (hyperglycemia) with low blood glucose (hypoglycemia) or HbA 1c is more reflective of elevated blood glucose levels, which do not change much during the day.Devices such as continuous blood glucose monitoring allow people with diabetes to constantly measure their blood glucose levels, checking every few minutes. Continuous use of blood glucose meters is becoming more common, and these devices are covered by many health plans, but not Medicare in the United States. Consumables are usually expensive as the sensors need to be changed at least every 2 weeks. Another useful test for determining whether HbA 1c values ​​are associated with large fluctuations in blood glucose levels throughout the day is 1,5-anhydroglucitol, also known as GlycoMark.GlycoMark only reflects cases where a person has hyperglycemia above 180 mg / dL over a two week period.

The hemoglobin A1 (HbA1) concentration is increased in both diabetic and renal impaired patients when measured by ion exchange chromatography. The thiobarbituric acid method (a chemical method specific for the detection of glycation) shows that patients with renal failure have similar glycated hemoglobin values ​​to those observed in normal subjects, suggesting that the high values ​​in these patients are the result of binding something else. …than glucose to hemoglobin.

In autoimmune hemolytic anemia, the concentration of HbA1 is not determined. The introduction of prednisolone will determine HbA1. In these circumstances, an alternative fructosamine test can be used, which also reflects the average blood glucose level over the previous 2–3 weeks.

All major institutions, such as the International Diabetes Federation, the European Association for the Study of Diabetes and the American Diabetes Association, propose an HbA level of 1c 48 mmol / mol (6.5 DCCT%) as a diagnostic level.The committee report also states that when testing for HbA 1c is not possible, should be tested for fasting and glucose tolerance. Diagnosing diabetes during pregnancy still requires measuring fasting gestational diabetes and glucose tolerance rather than glycated hemoglobin.

Modification by diet

A meta-analysis showed that probiotics caused a statistically significant decrease in glycosylated hemoglobin in type 2 diabetics.Trials with several strains of probiotics showed statistically significant reductions in glycosylated hemoglobin, while trials with individual strains did not.

Standardization and traceability

Hemoglobin A1c is now standardized and monitored by IFCC HPLC-CE and HPLC-MS. The transition to a new unit of measurement in mmol / mol is part of this standardization. The standardized test does not check blood iodine levels; Hypothyroidism or iodine supplementation is known to artificially increase A1c.


Testing for HbA1c has not been found to be beneficial in the treatment of diabetic cats and dogs and is not routinely used; Fructosamine is preferred instead.

See also


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