What is HbA1c and how does it relate to diabetes. How is the HbA1c test performed and what do the results mean. Why is HbA1c testing important for diabetes diagnosis and monitoring.

What is HbA1c and Why is it Important?

HbA1c, also known as glycated hemoglobin or glycosylated hemoglobin, is a crucial marker in diabetes management. This blood test provides valuable insights into a person’s average blood glucose levels over the past 2-3 months. Understanding HbA1c is essential for both diagnosing diabetes and monitoring long-term blood sugar control in individuals with the condition.

The Science Behind HbA1c

To comprehend the significance of HbA1c, it’s important to understand the underlying biology. Hemoglobin is a protein found in red blood cells that carries oxygen throughout the body. When glucose in the bloodstream combines with hemoglobin, it forms glycated hemoglobin. The higher the blood glucose levels, the more glycated hemoglobin is produced.

Is there a difference between normal and elevated HbA1c levels? Indeed, even individuals with normal blood glucose levels have some glycated hemoglobin in their blood. However, consistently high blood glucose levels result in a higher proportion of red blood cells with glycated hemoglobin.

The HbA1c Test: Procedure and Significance

The HbA1c test is a simple and effective way to assess long-term blood glucose control. Unlike daily blood glucose monitoring, which provides a snapshot of current levels, the HbA1c test offers a broader perspective on glucose management over time.

How is the HbA1c Test Performed?

The HbA1c test is a straightforward blood test that can be conducted at any time of day. One of its main advantages is that it doesn’t require fasting or any special preparation beforehand. Here’s what you can expect:

• A small blood sample is taken, usually from a vein in your arm
• The sample is sent to a laboratory for analysis
• Results are typically available within 24 hours

Does the HbA1c test cause any discomfort? Generally, the test is quick and causes minimal discomfort, similar to any routine blood draw.

Interpreting HbA1c Results: What Do the Numbers Mean?

Understanding your HbA1c results is crucial for managing diabetes effectively. The test results are typically reported in two ways: as a percentage or in units of mmol/mol (millimoles per mole).

Normal HbA1c Levels

A normal HbA1c result falls between 3.5% to 6% (15-42 mmol/mol). These values indicate that blood glucose levels have been well-controlled over the past few months.

HbA1c Levels for Diabetes Diagnosis

When using HbA1c for diabetes diagnosis, the following guidelines are generally applied:

• 6.5% (48 mmol/mol) or higher: Indicative of diabetes
• 5.7% to 6.4% (39-47 mmol/mol): Prediabetes
• Below 5.7% (39 mmol/mol): Normal

Is a single high HbA1c result enough to diagnose diabetes? Typically, doctors recommend a repeat test to confirm the diagnosis, especially if the patient shows no symptoms of diabetes.

HbA1c Targets for People with Diabetes

For individuals already diagnosed with diabetes, HbA1c targets may vary based on individual circumstances. However, general guidelines exist to help manage the condition effectively.

Recommended HbA1c Ranges

Most healthcare providers recommend the following HbA1c targets for people with diabetes:

• 6.5% to 7% (48-53 mmol/mol): Considered good control for most people with diabetes
• Below 7% (53 mmol/mol): Ideal target for reducing the risk of complications
• 7% to 8% (53-64 mmol/mol): May be appropriate for some individuals, depending on their overall health and risk factors

Are these targets the same for everyone with diabetes? It’s important to note that individual targets may vary based on factors such as age, overall health, and the presence of other medical conditions. Always consult with your healthcare provider to determine the most appropriate HbA1c target for your specific situation.

Factors Affecting HbA1c Levels

While HbA1c is generally a reliable indicator of blood glucose control, several factors can influence the results. Understanding these factors is crucial for accurate interpretation of HbA1c values.

Medical Conditions That Can Affect HbA1c

Certain medical conditions can lead to falsely high or low HbA1c readings:

• Anemia and other blood disorders
• Kidney disease
• Liver disease
• Certain medications
• Hemoglobinopathies (variant forms of hemoglobin)

Can lifestyle factors impact HbA1c levels? Indeed, factors such as diet, exercise, stress, and sleep patterns can all influence blood glucose levels and, consequently, HbA1c results.

The Benefits of HbA1c Testing in Diabetes Management

HbA1c testing offers several advantages in the diagnosis and management of diabetes. Understanding these benefits can help patients and healthcare providers make informed decisions about diabetes care.

Advantages of HbA1c Over Other Diabetes Tests

Compared to other diabetes tests, HbA1c offers unique benefits:

1. No fasting required: Unlike fasting blood glucose tests, HbA1c can be done at any time of day without special preparation.
2. Long-term perspective: HbA1c provides an average of blood glucose levels over 2-3 months, offering a more comprehensive view of glucose control.
3. Less day-to-day variability: HbA1c is less affected by short-term fluctuations in blood glucose levels.
4. Convenience: The test requires only a single blood sample and doesn’t involve drinking glucose solutions or multiple blood draws.

How often should HbA1c be tested? For most people with diabetes, doctors recommend HbA1c testing every 3-6 months. However, the frequency may vary based on individual circumstances and how well blood glucose levels are controlled.

HbA1c and Diabetes Complications: Understanding the Connection

The relationship between HbA1c levels and the risk of diabetes complications is a crucial aspect of diabetes management. Higher HbA1c levels are associated with an increased risk of developing various diabetes-related complications.

HbA1c and Long-term Health Risks

Research has shown that maintaining lower HbA1c levels can significantly reduce the risk of diabetes complications, including:

• Diabetic retinopathy (eye damage)
• Nephropathy (kidney damage)
• Neuropathy (nerve damage)
• Cardiovascular disease
• Stroke

By how much can lowering HbA1c reduce complication risks? Studies have demonstrated that even a 1% reduction in HbA1c can lead to a significant decrease in the risk of diabetes-related complications. For example, a 1% reduction in HbA1c has been associated with a 37% decrease in microvascular complications and a 21% reduction in diabetes-related deaths.

Strategies for Improving HbA1c Levels

For individuals with diabetes or those at risk of developing the condition, improving HbA1c levels is a key goal. Several strategies can help lower HbA1c and maintain better blood glucose control.

Lifestyle Modifications

Implementing healthy lifestyle changes can have a significant impact on HbA1c levels:

1. Balanced diet: Focus on whole grains, lean proteins, fruits, vegetables, and healthy fats. Limit processed foods and sugary drinks.
2. Regular exercise: Aim for at least 150 minutes of moderate-intensity aerobic activity per week, along with strength training exercises.
3. Weight management: Maintaining a healthy weight can improve insulin sensitivity and blood glucose control.
4. Stress reduction: Practice stress-management techniques such as meditation, yoga, or deep breathing exercises.
5. Adequate sleep: Aim for 7-9 hours of quality sleep per night, as poor sleep can affect blood glucose levels.

How quickly can lifestyle changes impact HbA1c levels? While individual responses may vary, many people see improvements in their HbA1c within 2-3 months of implementing consistent lifestyle changes.

Medication Management

For some individuals, lifestyle modifications alone may not be sufficient to achieve target HbA1c levels. In such cases, healthcare providers may recommend medications to help manage blood glucose levels more effectively:

• Metformin: Often the first-line medication for type 2 diabetes
• Sulfonylureas: Help stimulate insulin production
• DPP-4 inhibitors: Improve insulin sensitivity and reduce glucose production
• GLP-1 receptor agonists: Slow digestion and improve insulin production
• SGLT2 inhibitors: Help remove excess glucose through urine
• Insulin: May be necessary for some individuals with type 2 diabetes and is essential for those with type 1 diabetes

Is medication always necessary to improve HbA1c levels? While medication can be an important tool in managing diabetes, some individuals may be able to achieve their target HbA1c levels through lifestyle modifications alone, especially in the early stages of type 2 diabetes or prediabetes.

The Future of HbA1c Testing and Diabetes Management

As our understanding of diabetes and glucose metabolism continues to evolve, so too does the field of diabetes management and monitoring. Research into new technologies and approaches for measuring and interpreting HbA1c is ongoing, with the potential to revolutionize diabetes care in the coming years.

Emerging Technologies in Glucose Monitoring

Several innovative technologies are being developed to complement or potentially replace traditional HbA1c testing:

• Continuous Glucose Monitoring (CGM): Provides real-time glucose readings throughout the day and night
• Flash Glucose Monitoring: Allows for frequent glucose checks without finger pricks
• Glycated Albumin Testing: May offer advantages in certain populations where HbA1c is less reliable
• Advanced Glycation End-products (AGEs) Measurement: Could provide additional insights into long-term glucose control

How might these new technologies impact diabetes management? These advancements have the potential to offer more detailed and personalized information about glucose patterns, enabling healthcare providers and patients to make more informed decisions about diabetes management strategies.

Personalized Medicine in Diabetes Care

The future of diabetes management is likely to involve a more personalized approach, taking into account individual factors that can influence HbA1c levels and overall glucose control:

1. Genetic profiling: Identifying genetic markers that may influence an individual’s response to different diabetes treatments
2. Microbiome analysis: Understanding how gut bacteria affect glucose metabolism and diabetes risk
3. Artificial Intelligence (AI): Using machine learning algorithms to predict glucose trends and optimize treatment plans
4. Telemedicine: Enhancing remote monitoring and management of diabetes through digital health platforms

Will these advancements make HbA1c testing obsolete? While new technologies may offer additional insights, HbA1c testing is likely to remain an important tool in diabetes management for the foreseeable future. However, it may be used in conjunction with other advanced monitoring methods to provide a more comprehensive picture of an individual’s glucose control.

As research continues to advance our understanding of diabetes and glucose metabolism, the role of HbA1c testing in diabetes management may evolve. However, its importance in providing a long-term view of glucose control is likely to remain significant. By staying informed about current best practices and emerging technologies, individuals with diabetes can work with their healthcare providers to optimize their diabetes management strategies and improve their overall health outcomes.

HbA1c test results and diabetes

The HbA1c test is a useful, simple and inexpensive blood test that can be used to diagnose diabetes and also to monitor blood glucose control in people with known diabetes.

HbA1c stands for glycated haemoglobin, or glycosylated haemoglobin. An HbA1c blood test can give an indication of whether blood glucose levels have been higher than normal over the last few months, by looking at how much sugar (glucose) is bound in your red blood cells.

What is glycated haemoglobin?

Your red blood cells contain a protein called haemoglobin (Hb) which carries oxygen. Sugar (glucose) in your bloodstream can combine with the haemoglobin in red blood cells, forming glycated haemoglobin. Even people with normal blood glucose levels have some glycated haemoglobin in their blood, but if you have consistently high blood glucose levels, a higher proportion of red blood cells will have glycated haemoglobin. The HbA1c test measures the percentage of all haemoglobin that is bound to glucose.

The HbA1c level reflects the average blood glucose levels from the last 3 months or so. That’s because once glucose has attached to haemoglobin in a red blood cell, it stays there for the life of the red blood cell, which is around 3 months.

Why is this test done?

Doctors usually recommend that people with diabetes have an HbA1c test about every 3-6 months, as it gives an indication of the overall control of blood glucose levels over the previous 8-12 weeks. A raised HbA1c correlates with an increased risk of developing diabetes complications such as diabetic retinopathy.

HbA1c testing is used in addition to home blood glucose monitoring (which shows day to day blood sugar highs and lows) to help give a picture of whether your diabetes treatment is effective.

More recently, HbA1c tests have also been approved to be used in the diagnosis of diabetes.

How is the test done?

The HbA1c test is a simple blood test. The blood can be taken by your doctor or at a pathology lab. There is no need to fast before the test – you can eat and drink as normal. The results should be available within 24 hours.

What does HbA1c measure?

The test measures the percentage of haemoglobin that is bound to glucose, which reflects the average blood glucose concentration over last few months.

Glycosylated haemoglobin can be measured:

• as a percentage; or
• in units of mmol/mol, which is a newer way of measuring and reporting HbA1c results.

What’s a normal result for HbA1c?

A normal HbA1c result is between 3.5 to 6 per cent (15-42 mmol/mol).

What’s a bad HbA1c result?

Abnormal results (which would be higher than the normal range) indicate a possible diagnosis of diabetes or poor control of diabetes.

HbA1c to diagnose diabetes

If you are having an HbA1c test to help diagnose diabetes, a result of 6.5 per cent (48 mmol/mol) or higher is diagnostic of diabetes. A repeat test is often recommended to confirm the result, especially if you have no symptoms.

Your doctor will also want to talk with you about your lifestyle, such as your diet and how much physical activity you usually do.

People with known diabetes

If you have known diabetes and your HbA1c is 6.5 to 7 per cent (48-53 mmol/mol), your blood glucose control over the last few months would be considered to be good. Most doctors would recommend that people with diabetes should aim for this range. However, some people may have a target HbA1c range that is slightly higher than this.

If your levels are higher than your target range, that means that your blood sugar levels probably have not been well controlled recently. Your doctor will want to talk to you about your current treatments and whether any adjustments need to be made.

What is the benefit of HbA1c over other diabetes tests?

HbA1c is a simple blood test that does not require any fasting or other special preparation beforehand, and can be done at any time of the day.

This is compared with other tests that can be used in the diagnosis of diabetes. A fasting blood sugar level, as the name implies, requires you to fast (not eat food or drink) for a certain period of time before having the blood test.

An oral glucose tolerance test is another way to diagnose diabetes. It requires a special diet for 3 days before having the test, and then fasting overnight before the test. This test also involves having several blood tests over a couple of hours – before and after having to drink a certain volume of sweet liquid. The test is time consuming and some people find that drinking the liquid can make them feel sick.

Does a high HbA1c always mean diabetes?

No. There are some things other than diabetes that can affect HbA1c levels.

Most of us have type A haemoglobin (HbA, or adult haemoglobin), but some people have a variant form of haemoglobin. This is known as a haemoglobinopathy, and it can cause falsely high or low HbA1c results.

Iron deficiency and iron deficiency anaemia can give a falsely high result; and haemolytic anaemia, blood loss, chronic (ongoing) liver disease and chronic kidney disease can give a falsely low HbA1c result.

There are also some medicines and supplements that affect the results, including:

• iron, vitamin B12 and folate supplements;
• erythropoietin therapy;
• aspirin treatment;
• vitamin C or E supplements; and
• certain antiviral and antimicrobial medicines.

Your doctor will check before doing the test whether you have any factors that could alter the results.

1. Diabetes Australia. Blood glucose monitoring. https://www.diabetesaustralia.com.au/blood-glucose-monitoring (accessed Sep 2018).
2. Royal College of Pathologists of Australia. RCPA manual. HbA1c. https://www.rcpa.edu.au/Library/Practising-Pathology/RCPA-Manual/Items/Pathology-Tests/H/HbA1c (accessed Sep 2018).
3. d’Emden MC, Shaw JE, Jones GR, Cheung N Wah. Guidance concerning the use of glycated haemoglobin (Hb A1c) for the diagnosis of diabetes mellitus. Med J Aust 2015;203(2):89-90. https://www.mja.com.au/journal/2015/203/2/guidance-concerning-use-glycated-haemoglobin-hba1c-diagnosis-diabetes-mellitus (accessed Sep 218).
4. Diabetes: detection and diagnosis (published November 2013; amended February 2015). In: eTG complete. Melbourne: Therapeutic Guidelines Limited; 2018 Jul. https://tgldcdp.tg.org.au/ (accessed Sep 2018).
5. d’Emden M. Glycated haemoglobin for the diagnosis of diabetes. Aust Prescr 2014;37:98-100. https://www.nps.org.au/australian-prescriber/articles/glycated-haemoglobin-for-the-diagnosis-of-diabetes (accessed Sep 2018).

Glycohemoglobin (HbA1c, A1c) | Michigan Medicine

Overview

A glycohemoglobin test, or hemoglobin A1c, is a blood test that checks the amount of sugar (glucose) bound to the hemoglobin in the red blood cells. People who have diabetes or other conditions that increase their blood glucose levels have more glycohemoglobin (sugar bound to hemoglobin) than normal.

An A1c test can be used to diagnose prediabetes or diabetes. The A1c test checks the long-term control of blood glucose levels in people with diabetes. Most doctors think checking an A1c level is the best way to check how well a person is controlling his or her diabetes. This test can be done with a blood draw from a vein. Sometimes an A1c test can be done with blood from a finger stick.

A home blood glucose test measures the level of blood glucose only at that moment. Blood glucose levels change during the day for many reasons, including medicine, diet, exercise, and the level of insulin in the blood.

It is useful for a person who has diabetes to have information about the long-term control of blood sugar levels. The A1c test result does not change with any recent changes in diet, exercise, or medicines.

Glucose binds to hemoglobin in red blood cells at a steady rate. Since red blood cells last 3 to 4 months, the A1c test shows how much glucose is in the plasma part of blood. This test shows how well your diabetes has been controlled in the last 2 to 3 months and whether your diabetes treatment plan needs to be changed.

The A1c test can also help your doctor see how big your risk is of developing problems from diabetes, such as kidney failure, vision problems, and leg or foot numbness. Keeping your A1c level in your target range can lower your chance for problems.

Why It Is Done

This test is done to:

• Diagnose prediabetes and diabetes.
• Check your treatment for diabetes.

How To Prepare

You do not need to stop eating before you have an A1c test. This test can be done any time during the day, even after a meal.

How It Is Done

The health professional taking a sample of your blood will:

• Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
• Clean the needle site with alcohol.
• Put the needle into the vein. More than one needle stick may be needed.
• Attach a tube to the needle to fill it with blood.
• Remove the band from your arm when enough blood is collected.
• Put a gauze pad or cotton ball over the needle site as the needle is removed.
• Put pressure on the site and then put on a bandage.

How It Feels

The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.

Risks

Blood test

There is very little chance of a problem from having blood sample taken from a vein.

• You may get a small bruise at the site. You can lower the chance of bruising by keeping pressure on the site for several minutes.
• In rare cases, the vein may become swollen after the blood sample is taken. This problem is called phlebitis. A warm compress can be used several times a day to treat this.

Results

A1c is a blood test that checks the amount of sugar (glucose) bound to hemoglobin. The result is shown as a percentage. The result of your A1c test can also be used to estimate your average blood sugar level. This is called your estimated average glucose, or eAG. Your doctor will have your test results in a few days.

The American Diabetes Association (ADA) criteria to diagnose diabetes include the option of testing A1c. Your doctor may repeat the test to confirm the diagnosis of diabetes.

Normal

Each lab has a different range for what’s normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn’t in the normal range may still be normal for you.

If you have diabetes, talk to your doctor about your diabetes treatment plan and your target A1c goal.

High values

Some medical conditions can increase A1c levels, but the results may still be within a normal range. These conditions include Cushing’s syndrome, pheochromocytoma, and polycystic ovary syndrome (PCOS).

Corticosteroid treatment increases the A1c level.

What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include:

• Having severe blood loss or a blood transfusion in the last 3 months.
• Having certain medical conditions, such as sickle cell anemia, hemolytic anemia, some types of thalassemia, and severe kidney disease.
• Being on hemodialysis.
• Taking erythropoietin (ESA) medicine.
• Being in the second or third trimester of pregnancy.
• Having your spleen taken out. This changes the normal life cycle of red blood cells and A1c levels.

References

Citations

1. American Diabetes Association (2019). Standards of medical care in diabetes—2019. Diabetes Care, 42(Suppl 1): S1–S193. Accessed December 17, 2018.

Credits

Current as of:
August 31, 2020

Author: Healthwise Staff
Medical Review:
E. Gregory Thompson MD – Internal Medicine
Kathleen Romito MD – Family Medicine
Adam Husney MD – Family Medicine
Matthew I. Kim MD – Endocrinology
David C.W. Lau MD, PhD, FRCPC – Endocrinology

Current as of: August 31, 2020

Author:
Healthwise Staff

Medical Review:E. Gregory Thompson MD – Internal Medicine & Kathleen Romito MD – Family Medicine & Adam Husney MD – Family Medicine & Matthew I. Kim MD – Endocrinology & David C.W. Lau MD, PhD, FRCPC – Endocrinology

A1C test – Mayo Clinic

Overview

The A1C test is a common blood test used to diagnose type 1 and type 2 diabetes. If you’re living with diabetes, the test is also used to monitor how well you’re managing blood sugar levels. The A1C test is also called the glycated hemoglobin, glycosylated hemoglobin, hemoglobin A1C or HbA1c test.

An A1C test result reflects your average blood sugar level for the past two to three months. Specifically, the A1C test measures what percentage of hemoglobin proteins in your blood are coated with sugar (glycated). Hemoglobin proteins in red blood cells transport oxygen.

The higher your A1C level is, the poorer your blood sugar control and the higher your risk of diabetes complications.

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Why it’s done

The results of an A1C test can help your doctor or other health care provider:

• Diagnose prediabetes. If you have prediabetes, you have a higher risk of developing diabetes and cardiovascular disease.
• Diagnose type 1 and type 2 diabetes. To confirm a diabetes diagnosis, your doctor will likely look at the results of two blood tests given on different days — either two A1C tests or the A1C test plus another test, such as a fasting or random blood sugar test.
• Monitor your diabetes treatment plan. The result of an initial A1C test also helps establish your baseline A1C level. The test is then repeated regularly to monitor your diabetes treatment plan.

How often you need the A1C test depends on the type of diabetes, your treatment plan, how well you’re meeting treatment goals and your primary care doctor’s clinical judgment. For example, the A1C test may be recommended:

• Once every year if you have prediabetes
• Twice a year if you don’t use insulin and your blood sugar level is consistently within your target range
• Four times a year if you take insulin or have trouble keeping your blood sugar level within your target range

You may need more-frequent A1C tests if your doctor changes your diabetes treatment plan or you begin taking a new diabetes medication.

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How you prepare

The A1C test is a simple blood test. You don’t need to fast for the A1C test, so you can eat and drink normally before the test.

What you can expect

During the A1C test, a member of your health care team takes a blood sample by inserting a needle into a vein in your arm or pricking your finger tip with a small, pointed lancet. If the blood is taken from a vein, the blood sample is sent to a lab for analysis.

Blood from a finger prick may be analyzed in your doctor’s office for same-day results. This in-office test is only used for monitoring your treatment plan, not for diagnosis or screening.

Results

A1C test results are reported as a percentage. A higher A1C percentage corresponds to higher average blood sugar levels. Results for a diagnosis are interpreted as follows:

• Below 5.7% is normal.
• 5.7% to 6.4% is diagnosed as prediabetes.
• 6.5% or higher on two separate tests indicates diabetes.

For most adults living with diabetes, an A1C level of less than 7% is a common treatment target. Lower or higher targets may be appropriate for some people.

The target of less than 7% is associated with a lower risk of diabetes-related complications. If your A1C level is above your target, your doctor may recommend an adjustment in your diabetes treatment plan.

A1C and self-monitoring

A part of your treatment plan will include self-monitoring at home with a blood glucose meter or other device. Your health care team will direct you on how often and when you should test your blood sugar.

Your self-monitoring device reports your blood sugar levels in milligrams of sugar per deciliter (mg/dL) or millimoles of sugar per liter (mmol/L). The measurement shows your blood sugar level at the time you do the test. Therefore, there is some variability throughout the day based on eating, exercise, stress and other factors.

Self-monitoring helps you make choices about diet and exercise and daily treatment goals, but it also helps you track whether you are meeting your A1C target. For example, if your A1C target is below 7%, your self-monitoring blood sugar levels should be, on average, below 154 mg/dL (8.6 mmol/L).

A1C test results generally correspond with the following results of blood sugar levels:

Limitations of the A1C test

Some factors may interfere with the accuracy of A1C test results. These include:

• Pregnancy
• Recent or heavy blood loss
• Recent blood transfusion
• Conditions that result in insufficient red blood cells (anemias)
• Hemoglobin variants

The most common form of the oxygen-transporting hemoglobin protein is called hemoglobin A. The presence of other variants of the protein may result in inaccurate A1C test results. Hemoglobin variants are more common among people of African, Mediterranean or Southeast Asian descent.

If you have a hemoglobin variant, your test may need to be sent to a specialized lab or you may need a different test for diagnosis and monitoring of diabetes.

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Hemoglobin A1C – StatPearls – NCBI Bookshelf

Introduction

The hemoglobin A1c (glycated hemoglobin, glycosylated hemoglobin, HbA1c, or A1c) test is used to evaluate a person’s level of glucose control. The test shows an average of the blood sugar level over the past 90 days and represents a percentage. The test can also be used to diagnose diabetes.[1]

Hemoglobin is a protein only found in red blood cells. In fact, hemoglobin is what gives blood its bright red coloring. Since red blood cells live about an average of three months, the A1c test will reflect those red blood cells that are present in the bloodstream at the time of the test; this is why the A1c serves as an average of blood sugar control.

The main job of hemoglobin is to carry oxygen from the lungs to all the cells of the body. Hemoglobin becomes glycated or coated with glucose from the bloodstream. The amount of glucose that is present in the blood will attach to the hemoglobin protein, and increased glucose levels will reflect on the surface of the hemoglobin protein, thereby rendering a higher A1c level.[2]

Etiology and Epidemiology

The Diabetes Control and Complications Trial (DCCT)[3] was a landmark trial that provided a wealth of data on A1c and its correlation to blood glucose levels, as well as establishing specific treat to target A1c goals. From the completion of the trial, the National Glycohemoglobin Standardization Program (NGSP) was formed to define a standardized assay that was usable across laboratories.  

The DCCT trial reported that a higher mean A1c level was the dominant predictor of diabetic retinopathy progression. Tighter control shown by levels of HbA1c in the 7% range or lower, were correlated with 35-76% decrease in microvascular complications, like retinopathy, nephropathy and neuropathy, in patients with type 1 diabetes. In addition to the determination of A1c levels predicting progression of microvascular complications, the extension of DCCT into EDIC study showed benefit in the cardiovascular risk and mortality in the longterm for those patients with lower levels of HbA1c.[4][5][6]

Pathophysiology

People with diabetes need to have their A1c checked regularly to determine if their average blood glucose levels are within the target range. The American Diabetes Association (ADA) recommends that the HbA1c is checked twice a year in patients that are stable and well controlled, versus every 3 months in patients with changes in their medications, or not well controlled.  [7]

Specimen Requirements and Procedure

The HbA1c test can either be done as a point of care (POC), STAT test, or by sending a sample to a laboratory. The POC test uses a STAT analyzer that evaluates the A1c from a capillary fingerstick. The laboratory test uses a teaspoon of blood drawn from a venous sample into a K2 EDTA (lavender top) tube. The sample gets processed as whole blood.

Diagnostic Tests

The venous sample A1c test may be used as a diagnostic tool in clinical practice when determining diabetes risk or onset. Due to the variability of capillary point of care testing, any A1c done by capillary sample should be confirmed with a venous sample before rendering the diagnosis.

For an HbA1c test to classify as normal, or in the non-diabetic range, the value must be below 5.7 %. Anyone with an HbA1c value of 5.7 % to 6.4 % is considered to be prediabetic, while diabetes can be diagnosed with a HbA1c of 6.5% or higher.

Tests should be sent to a laboratory certified by the NGSP to ensure results are standardized. [8][9]

Testing Procedures

The HbA1c test done by a point of care machine in a doctor’s office may be less accurate than one that is drawn from a venous sample and processed in a laboratory. Typically, the results can vary by different laboratories by as much as 0.5%.

The HbA1c test should be performed using an NGSP-approved method.

Interfering Factors

There are several conditions where the HbA1c test can produce inaccurate results. People diagnosed with sickle cell anemia, thalassemia, anemia, kidney failure, liver disease, or patients receiving blood transfusions can experience altered results due to the longevity of the red blood cell. HbA1c measurement in these patients must be interpreted with caution and should be confirmed with plasma glucose samples to diagnose diabetes.[10]

A falsely low HbA1c value can result from several conditions including high altitude, pregnancy, hemorrhage, blood transfusion, erythropoietin administration, iron supplementation, hemolytic anemia, chronic kidney failure, liver cirrhosis, alcoholism, folic acid deficiency, sickle cell anemia, and spherocytosis. Vitamin C supplementation can either increase or decrease the HbA1c level depending on the method used for its measurement.[15]

On the other end of the spectrum, a falsely high HbA1c can be due to a lack of available iron in the blood. This condition can result from iron deficiency anemia, infection-induced anemia, or tumor-induced anemia. Hemoglobinopathies such as thalassemia can also cause a falsely high HbA1c. Other causes of falsely high HbA1c levels include hypertriglyceridemia, organ transplantation, and hyperglycation in certain ethnic groups. Medications such as immunosuppressants and protease inhibitors can sometimes lead to a falsely high HbA1c.[10][7][11][12]

Results, Reporting, Critical Findings

Relationship Between A1c and Glucose Level

The HbA1c percentage equates to an average glucose level in the body that the patient experienced over the past 90 days.[13][14][15]

A1c (%)       Average Blood Glucose (mg/dL)

6                  126

8                  183

10                240

12                298

14                355

Clinical Significance

Hemoglobin A1c serves as an indicator of overall glycemic control and a reflection of the average blood sugar over the past three months. [2]

Quality control and Lab Safety

Laboratories can use several methods to determine HbA1c. High performance liquid chromatography (HPLC) method is one of the most popular methods because it can eliminate labile components that other methods such as immunoassay or affinity chromatography use.[16]

The point of care (POC) machine is widely used as well to determine HbA1c levels. The variety of POC machines on the market can make it difficult to determine the one best suited for one’s practice. Also, there is a shortage of information comparing the different machines. When using POC testing, one should keep in mind that POC values are often below results reported by a laboratory test, with the mean difference being -0.5%.

Enhancing Healthcare Team Outcomes

All clinicians who look after diabetic patients need to know what HbA1c means. In general, HbA1c provides a measure of the average glucose concentration over three months.

Hemoglobin A1c is often used as an outcome measure to determine if an intervention in a population is successful by showing a decrease in HbA1c by a certain percentage. There is a movement within the medical community to move away from using HbA1c as an exclusive standard of care test to measure patient response to treatment. The Estimated Average Glucose (eAG) is the newest proposed method. This method uses data obtained by continuous glucose monitors (CGMs) that record blood glucose 24 hours a day. This method gives providers a more accurate view of the blood sugar average and fluctuations, but the method is not available to all patients on a wide-spread basis.

As per ADA guidelines, the levels of HA1c should be measured twice a year in stable patients and at least four times in patients who have glucose fluctuations or those who have had a change in their diabetic treatment. Hemoglobin A1c is one of the preferred diabetes diagnostic tests today. The blood draw can occur at any time, and there are no special handling requirements. However, to ensure that the A1c value is correct, clinicians need to be aware of the causes of false-positive and false-negative results.

Since many patients with diabetes have their condition managed in outpatient clinics, the diabetic nurse should be fully aware of HbA1c values and when to refer the patient to an endocrinologist for further workup and treatment. Pharmacists are also required to fully understand and interpret this test, as they will be involved in glycemic management medication agent selection, dosing, and monitoring.  Both the nurse and/or pharmacist need to inform the treating physician regarding any changes in hemoglobin A1c and verify patient medication compliance. Hemoglobin A1c is a very valuable tool in the fight against diabetes and other glycemic control disorders, but to be effective, it functions best in an interprofessional healthcare team environment. [Level V]

References

1.

Gilstrap LG, Chernew ME, Nguyen CA, Alam S, Bai B, McWilliams JM, Landon BE, Landrum MB. Association Between Clinical Practice Group Adherence to Quality Measures and Adverse Outcomes Among Adult Patients With Diabetes. JAMA Netw Open. 2019 Aug 02;2(8):e199139. [PMC free article: PMC6694385] [PubMed: 31411713]

2.

Sherwani SI, Khan HA, Ekhzaimy A, Masood A, Sakharkar MK. Significance of HbA1c Test in Diagnosis and Prognosis of Diabetic Patients. Biomark Insights. 2016;11:95-104. [PMC free article: PMC4933534] [PubMed: 27398023]

3.

Diabetes Control and Complications Trial Research Group. Nathan DM, Genuth S, Lachin J, Cleary P, Crofford O, Davis M, Rand L, Siebert C. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus. N Engl J Med. 1993 Sep 30;329(14):977-86. [PubMed: 8366922]

4.

Nathan DM., DCCT/EDIC Research Group. The diabetes control and complications trial/epidemiology of diabetes interventions and complications study at 30 years: overview. Diabetes Care. 2014;37(1):9-16. [PMC free article: PMC3867999] [PubMed: 24356592]

5.

Nathan DM. Realising the long-term promise of insulin therapy: the DCCT/EDIC study. Diabetologia. 2021 May;64(5):1049-1058. [PubMed: 33550441]

6.

Lachin JM, Orchard TJ, Nathan DM., DCCT/EDIC Research Group. Update on cardiovascular outcomes at 30 years of the diabetes control and complications trial/epidemiology of diabetes interventions and complications study. Diabetes Care. 2014;37(1):39-43. [PMC free article: PMC3868002] [PubMed: 24356596]

7.

American Diabetes Association. 6. Glycemic Targets: Standards of Medical Care in Diabetes-2021. Diabetes Care. 2021 Jan;44(Suppl 1):S73-S84. [PubMed: 33298417]

8.

American Diabetes Association. 6. Glycemic Targets: Standards of Medical Care in Diabetes-2019. Diabetes Care. 2019 Jan;42(Suppl 1):S61-S70. [PubMed: 30559232]

9.

Qaseem A, Wilt TJ, Kansagara D, Horwitch C, Barry MJ, Forciea MA, Clinical Guidelines Committee of the American College of Physicians. Fitterman N, Balzer K, Boyd C, Humphrey LL, Iorio A, Lin J, Maroto M, McLean R, Mustafa R, Tufte J. 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. Ann Intern Med. 2018 Apr 17;168(8):569-576. [PubMed: 29507945]

10.

Heinemann L, Freckmann G. Quality of HbA1c Measurement in the Practice: The German Perspective. J Diabetes Sci Technol. 2015 May;9(3):687-95. [PMC free article: PMC4604529] [PubMed: 25691655]

11.

Radin MS. Pitfalls in hemoglobin A1c measurement: when results may be misleading. J Gen Intern Med. 2014 Feb;29(2):388-94. [PMC free article: PMC3912281] [PubMed: 24002631]

12.

Shepard JG, Airee A, Dake AW, McFarland MS, Vora A. Limitations of A1c Interpretation. South Med J. 2015 Dec;108(12):724-9. [PubMed: 26630892]

13.

van ‘t Riet E, Alssema M, Rijkelijkhuizen JM, Kostense PJ, Nijpels G, Dekker JM. Relationship between A1C and glucose levels in the general Dutch population: the new Hoorn study. Diabetes Care. 2010 Jan;33(1):61-6. [PMC free article: PMC2797987] [PubMed: 19808928]

14.

Sayed A, Alyafei F, De Sanctis V, Soliman A, Elgamal M. Translating the HbA1c assay into estimated average glucose values in children and adolescents with type 1 diabetes mellitus. Acta Biomed. 2018 May 23;89(S5):22-26. [PMC free article: PMC6179094] [PubMed: 30049928]

15.

Lai LC. Global standardisation of HbA1c. Malays J Pathol. 2008 Dec;30(2):67-71. [PubMed: 19291914]

16.

Kawano K. Quality control, quality assessment of laboratory tests, HbA1c. Southeast Asian J Trop Med Public Health. 1999;30 Suppl 3:117-21. [PubMed: 10926271]

In Diabetics, What Does A1c Stand For?- An Adult Type Hemoglobin

Diabetes is one of the most common diseases affecting today’s generation. In this case, many diabetics, both young and old, may already be aware of what  a1c stands for since they must have undergone the procedure during one of their laboratory tests. With the increasing prevalence of unhealthy lifestyle habits as well as genetic risks, the number of individuals who suffer from increased blood sugar levels has increased steadily.

Diabetes does not only affect the old people now but there is the new crowd of people who suffer from a thing called juvenile diabetes. A condition which affects children.  But for the benefit of those who are new to the term or would like to understand it better, we will discuss it on this page.

In Diabetics, What Does A1c Stand For?

What does a1c stand for then? A stands for adult type hemoglobin. A1c is a minor component of hemoglobin – a pigment of the blood that carries oxygen and gives it its red color – where glucose binds.

If in any case, you have heard someone asking what does hba1c stand for, kindly note that both mean the same and refer to the same thing. A1c is also referred to by its other names such as the hba1c or hemoglobin a1c, glycosylated hemoglobin or glycosylated hemoglobin. Hence, these terms are often interchanged.

What Is The Purpose Of Measuring HBA1C?

The levels of a1c depend on the concentration of your blood glucose. The higher the concentration of glucose present in your blood, the higher will your a1c level be. It usually reflects the average glucose levels for the past six to eight weeks. Other studies indicate that it can reflect up to 3 months, of your life and is not influenced by the daily fluctuations of your blood glucose levels.

Since it is an average measurement that signifies the past six to eight weeks, it serves as a good indicator of whether you have been able to control your blood glucose levels or not. It is certainly useful for diabetic patients who need to check whether their lifestyle choices such as diet, exercise and medications are working effectively or not.

What Is An A1c Test?

The a1c test is the name of the blood test conducted to provide information regarding your average blood glucose levels.  Also commonly referred to as your blood sugar, and the test shows the readings for the past three months. The a1c test is always used in the management of diabetes as well as in diabetic researches and studies.

The result of this test is reported through percentages. The higher your percentage is, the higher your blood glucose levels.

How To Interpret Results

After asking what hba1c stands for, people are also keen to know what the normal levels are. It is essential for a person to know the interpretation of the results so that he or she will be able to pinpoint the problems in the blood sugar levels. An average glycosylated hemoglobin level is below 5.7 percent.

If you have an a1c level of above 6.5 percent, expect that you will be considered a diabetic patient. On the other hand, if your a1c level ranges from 5.7 to 6.4 percent, you will be labeled as a prediabetic individual. Once you are a prediabetic patient, you should be careful of what you eat in order to help prevent a full-blown diabetic illness.

You still have the ability to control the situation and can prevent becoming a diabetic, all you have to do is choose a proper and healthy lifestyle.

Is A1c Test Really Accurate?

Unfortunately, the hba1c test is not that accurate. The result may be 0.5 percent higher or lower than your actual percentage. For example, if you measured an a1c level of 6 percent, your real a1c level is ranged between 5.5 to 6.5 percent.

Is There A Possibility That An A1c Test Gives A False Result?

Unfortunately again, yes. The test is not 100% accurate and reliable so to speak. If the a1c test does not give the same result as the blood glucose test (another test used to diagnose diabetes), you should consider some interference or factors that may have lead to the inaccurate result.

These factors may be higher for people of Southeast Asian origin, as well as people of Mediterranean or African descent. People who also have family members that are diagnosed with thalassemia or sickle cell anemia may also be at risk for such incorrect readings due to the interference. This is because these people may have a rare type of hemoglobin known as hemoglobin variant. Haemoglobin variant may interfere with some a1c test results. It is also a bit hard to distinguish who among these people are affected by such interferences because they do not exhibit symptoms and most of them are not even aware that they have a hemoglobin variant in their blood.

Additionally, there is nothing to break your head over because people who have false results from one type of hba1c test may do a different kind of a1c test which may give the correct result.

People who are having anemia and severe bleeding may also experience a false result because they will usually have a fallaciously low reading of their a1c levels due to their condition. On the other hand, a falsely elevated a1c level can be noticed in people with iron deficiency anemia or those with other conditions that result in very low iron in the body. Other causes that may lead to false readings are kidney failure and liver disease.

Also Read- Popular People With Diabetes

Is A1c Test Used To Monitor All Types Of Diabetes?

The a1c test is used to control and diagnose the blood glucose levels of people with type 1 and type 2 diabetes. However, it is not being used to control gestational diabetes, though the test can be utilized during the pregnant woman’s first visit to the health care facility to see if she has some risk factors of undiagnosed diabetes before delivery occurs.

During the pregnancy period, the oral glucose tolerance test or the OGTT, is used to check for diabetes that may develop. After the delivery of the baby, blood glucose tests will be used to check if diabetes persists, rather than the a1c test.

HGA1C – Hemoglobin A1c

HGA1C – Hemoglobin A1c

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HbA1c test – diagnosing and monitoring diabetes

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What is being tested?

HbA1c is a blood test that is used to help diagnose and monitor people with diabetes. It is also sometimes called a haemoglobin A1c, glycated haemoglobin or glycosylated haemoglobin.

HbA1c refers to glucose and haemoglobin joined together (the haemoglobin is ’glycated’). Haemoglobin is the protein in red blood cells that carries oxygen throughout the body. The amount of HbA1c formed is directly related to the amount of glucose in the blood.

Red blood cells live for up to 4 months, so HbA1c gives an indication of how much sugar there has been in the blood over the past few months. It’s different to the blood glucose test, which measures how much sugar is in the blood at that moment.

Why would I need this test?

The test for HbA1c is used to diagnose and monitor diabetes.

For people who have diabetes, the test is used to indicate how well the diabetes has been controlled over the last few months. People with diabetes are advised to have this test every 3 to 6 months, or more frequently if it is not under control.

This is important. The higher the HbA1c, the greater the risk of developing complications such as problems with your eyes and kidneys.

How to prepare for this test

No preparation is needed for this test.

Understanding your results

If you have not previously been diagnosed as having diabetes, an HbA1c of 6.5% or more can indicate that you do have diabetes. If your level is lower than this, you might need other tests to check whether you have diabetes or not.

If you do have diabetes, your doctor will usually aim for an HbA1c of 6.5-7%. If the HbA1c is higher than the target range, your doctor may consider changing your treatment or closer monitoring.

There are some medical conditions, such as anaemia, that change red blood cells and affect your HbA1c result.

You should discuss the results with your doctor to see what they mean in your particular situation.

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Glycosylated hemoglobin – norm, analysis, table, determination of the level of glycosylated hemoglobin (HbA1c)

Published: 16.04.2012 Updated: 29.07.2021 Views: 131 926

It is very important in the management of patients with diabetes mellitus to achieve optimal blood glucose levels.The patient can control the level of glucose in the blood independently (with portable glucometers) or in the laboratory.

The result of a single determination of glucose in the blood shows the concentration of glucose at the time of sampling, therefore, it is not possible to make any assumptions about the state of the patient’s carbohydrate metabolism between measurements. It is possible to assess carbohydrate metabolism in a patient over a long period of time only by measuring the concentration of glycated hemoglobin in the blood, according to the recommendations of the Committee on the Control of Diabetes and Its Clinical Complications (DCCT).

According to studies conducted by DCCT, it was shown that the risk of development and progression of long-term complications of type 1 diabetes is closely related to the degree of efficiency of glycemic control, expressed in the content of glycosylated hemoglobin in the blood [10]. Experts from the UK have shown that a decrease in the patient’s blood glucose, assessed by the HbA1c concentration, reduces the incidence of microangiopathies in type 2 diabetes mellitus [4].

Characteristics of the indicator

Glycosylated hemoglobin (the term “glycated hemoglobin” is also used) is formed as a result of non-enzymatic attachment of glucose to the N-terminal regions of β-chains of hemoglobin A1 _{globin and is designated as HbA1c.The HbA1c concentration is directly proportional to the average blood glucose concentration. In healthy people, the concentration of HbA1c in the blood is from 4 to 6%, in patients with diabetes mellitus, its level is 2-3 times higher (depending on the degree of hyperglycemia).}

The formed HbA1 accumulates inside the erythrocytes and remains during the entire life of the erythrocyte. The half-life of erythrocyte circulation in the bloodstream is 60 days, thus the HbA1c concentration reflects the patient’s glycemic level 60-90 days before the study [2, 3].

A huge number of studies using traditional methods of glucose measurement have confirmed the relationship between HbA1c and the patient’s glycemic level [12-14]. The results of studies conducted by the DCCT in the 90s served as the basis for confirming the hypothesis that the level of HbA1c reflects the level of glucose in the blood and is an effective criterion for monitoring patients with diabetes mellitus.

Standardization of methods for the study of glycosylated hemoglobin

In the early 90s, there was no interlaboratory standardization of methods for measuring glycosylated hemoglobin, which reduced the clinical effectiveness of this test [15-17].In this regard, the American Association of Clinical Chemistry in 1993 formed a subcommittee on the standardization of methods for measuring glycosylated hemoglobin. As a result of his work, the National Glycosylated Hemoglobin Research Standardization Program (NGSP) was developed. Manufacturers of test kits for measuring glycosylated hemoglobin were required to undergo rigorous testing to ensure that the results match the data obtained by the DCCT reference methods. In the event of a positive test result, the manufacturer is issued a “DCCT Certificate of Conformity”.The American Diabetes Association recommends that all laboratories use only NGSP-certified tests [7].

There are currently many methods for studying glycosylated hemoglobin:

• liquid chromatography;
• affinity chromatography;
• electrophoresis;
• Columnar Techniques;
• immunological methods.

When a laboratory chooses an analyzer for the study of glycosylated hemoglobin, preference should be given to analyzers based on the DCCT reference method, which is liquid chromatography.The use of standardized test methods enables the laboratory to obtain results that can be compared with data obtained using reference methods and published by the DCCT. This comparison maximizes the reliability of the research results.

It is extremely important that the attending physician uses in his work the research results obtained only in those laboratories that conduct research on glycosylated hemoglobin using methods certified by NGSP.

Study of the concentration of HbA1c in the laboratories of the Association “Citylab”

The concentration of glycosylated hemoglobin (HbA1c) in the laboratories of the Association “Citylab” is determined by the reference method (DCCT) high performance liquid chromatography (HPLC), (the method is certified by NGSP), on D 10 analyzers from Bio-Rad, which is the world leader in the production of glycosylated hemoglobin. This study is 23-10-002 – Glycosylated Hemoglobin.

Estimated mean blood glucose

The DCCT research team demonstrated the clinical significance of HbA1c as an estimate of the mean blood glucose concentration (over 60-90 days). In these studies, a daily glucose profile (seven measurements daily) was recorded in patients every 3 months. The resulting profile was compared with the HbA1c level. Over the course of 9 years, more than 36,000 studies have been carried out. Empirically, a linear relationship between the average glucose and HbA1c levels was obtained:

Average glucose concentration (mg / 100 ml) = 30.9 x (HbA1c) -60.6, where:

HbA1c – concentration of glycosylated hemoglobin.

Simply put, a 1% change in HbA1c corresponds to a 30 mg / 100 ml (1.7 mmol / L) change in mean glucose.

Note: This relationship was obtained from capillary blood glucose concentration studies. Serum glucose concentration is approximately 15% higher.

The diagram (Fig. 1) [11] can be used to interpret the results of HbA1c studies.

Rice.1. Diagram of the control of carbohydrate metabolism in patients with diabetes mellitus

Note: The concentration of glucose is indicated in mmol / l, in parentheses in mg / 100 ml, 1 – High risk of developing long-term complications such as retinopathy, nephropathy and neuropathy. 2 – Increased risk of hypoglycemic reactions in patients with type 1 or 2 diabetes when taking insulin or oral hypoglycemic drugs.

To convert the concentration of glucose in mg / 100 ml to SI units (mmol / L), use the following formula:

Glucose (mg / 100 ml) x 0.0555 = Glucose (mmol / L)

Recommended test frequency

The American Diabetes Association recommends that for patients whose therapy has been successful (stable level of carbohydrate metabolism), the HbA1c test should be carried out at least 2 times a year, while in case of dietary or treatment changes, the frequency of examination should be increased to 4 times a year [ 7].In the Russian Federation, according to the Federal Target Program “Diabetes Mellitus”, the HbA1c study should be carried out 4 times a year for any type of diabetes [1].

According to the recommendations of the American Diabetes Association, women with diabetes mellitus in the period prior to pregnancy need a special monitoring regimen. It is recommended to reduce the level of HbA1c to create optimal conditions for conception and development of the fetus in the body of the expectant mother. At the beginning, HbA1c should be tested monthly.When, with appropriate therapy, carbohydrate metabolism is stabilized, the HbA1c study should be carried out at intervals of 6-8 weeks until the moment of conception [5, 6].

Modern studies have shown that many patients do not adhere to the recommended interval between studies [8], however, experts have come to the general opinion that regular studies of the HbA1c content significantly reduce the risk of complications in patients with diabetes mellitus.

Interpretation of research results

The task of glucose-lowering therapy in diabetes mellitus is to normalize blood glucose levels.Studies within the DCCT have shown that intensive treatment prevents the patient from developing long-term complications such as retinopathy, nephropathy and neuropathy, or significantly delays their clinical manifestation. If patients strictly adhere to a regimen aimed at normalizing carbohydrate metabolism, the incidence of retinopathy decreases by 75%, nephropathy – by 35-36%, the risk of polyneuropathy decreases by 60% [10].

Below are the therapeutic goals in the treatment of diabetes mellitus according to the Federal Target Program “Diabetes mellitus”.

Table 1.

Therapeutic goals in the treatment of type 1 diabetes mellitus [1, 18]

Table 2.

Therapeutic goals in the treatment of type 2 diabetes mellitus [1, 19]

Note: The values ​​in parentheses are glucose values ​​in mg / 100 ml.

The Federal Target Program “Diabetes Mellitus” [1] adopted the values ​​recommended by the European Diabetes Commission [18, 19].

When assessing the results of treatment in patients with concomitant diseases, young people, the elderly, pregnant women and patients with an unusual pattern of diabetes mellitus, it is necessary to apply other criteria for stabilizing carbohydrate metabolism.

With an inadequate level of carbohydrate metabolism in a patient, additional measures are required, which depend on the clinical picture of the patient’s disease, such measures may include:

• Advanced Patient Education for Self-Monitoring of Glucose Levels;

90,026 organization of patient support groups;

• Regular examination by an endocrinologist;
• changes in drug therapy;
• More frequent testing of glucose and HbA1c concentrations.

Conclusions

1. The HbA1c study allows you to assess the level of glycemia in a patient with diabetes mellitus for 60-90 days prior to the study.
2. This study makes it possible to monitor the course of the disease and control the adequacy of the treatment.
3. The HbA1c study is necessary to assess the risk of complications in a patient with diabetes mellitus.

Literature Used

1. Dedov I.I., Shestakova M.V., Maksimova M.A. Federal target program “Diabetes mellitus”. // Moscow, 2002, 84 p.
2. Peters – Harmel E., Mathur R. Diabetes mellitus. Diagnostics and treatment. // Practice, 2008.
3. Popova Yu.S. Diabetes. // Krylov, 2008.
4. ADA. Implications of the United Kingdom Prospective Diabetes Study (Position Statement). // Diabetes Care 1999, (SI), 27-31.
5. ADA. Standards of Medical Care for Patients With Diabetes Mellitus (Position Statement).// Diabetes Care 1999, (SI), 32-41.
6. ADA. Preconception Care of Women With Diabetes (Position Statement). // Diabetes Care 1999, (SI), 62-63.
7. ADA. Tests of Glycemia in Diabetes (Position Statement). // Diabetes Care 1999, (SI) 77-79.
8. Auxter S. Another Study Shows Laboratory Tests are Underutilized. // Clin Lab News 1998, 24 (9): 24-5.
9. Bodor G., Little R., Garrett N. et al. Standardization of Glycohemoglobin Determinations in the Clinical Laboratory: Three Years Experience.// Clin Chem 1992; 38: 2414-18.
10. DCCT Research Group. The Effect of Intensive Treatment of Diabetes on the Development and Progression of Long – Term Complications in Insulin – Dependent Diabetes Mellitus. // Engl J Med 1993; 329: 977-86.
11. Goldstein D.E., Little R.R. Bringing Order to Chaos: Standardizing the Hemoglobin A1c Assay. // Contemp Int Med 1997; 9 (5): 27-32 /
12. Gonen B. A., Rubinstein A. H., Rochman H. et al. Hemoglobin A1: An Indicator of the Metabolic Control of Diabetic Patients.// The Lancet 1977, Oct 8; 2 (804): 734-7.
13. Koenig R. J., Peterson C. M., Kilo C. et al. Hemoglobin A1c as an Indicator of the Degree of Glucose Intolerance in Diabetes. // Diabetes 1976, 25 (3): 230-2.
14. Koenig R.J., Peterson C.M., Jones R.L. et al. Correlation of Glucose Regulation and Hemoglobin A1c in Diabetes Mellitus. // Engl J Med 1976, 295 (8): 417-20.
15. Little R.R., England J.D., Wiedmeyer H.M. et al. Interlaboratory Standardization of Glycated Hemoglobin Determinations.// Clin Chem 1986; 32: 358-60.
16. Little R.R., England J.D., Wiedmeyer H.M. et al. Interlaboratory Comparison of Glycated Hemoglobin Results: College of American Pathologists (CAP) Survey Data. // Clin Chem 1991; 37: 1725-29.
17. Little R.R., England J.D., Wiedmeyer H.M. et al. Interlaboratory Standardization of Measurements of Glycohemoglobin. // Clin Chem 1992; 38: 2472-78.
18. European Diabetes Policy Group. Guidelines for a desktop guide to Type 1 (insulindependent) Diabetes Mellitus.- International Diabetes Federation European Region. – 1998.
19. European Diabetes Policy Group. Guidelines for a desktop guide to Type 2 Diabetes Mellitus. – International Diabetes Federation European Region. – 1998 – 1999.

Glycated hemoglobin (HbA1c)

Glycated (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, which helps to start timely and adequate treatment, which will definitely give positive results to improve the patient’s condition.

What is glycated (or glycated, HbA1c) is hemoglobin associated with sugar (blood glucose).It reflects the average blood glucose value over the past three months.

If the level of glycated hemoglobin is elevated, this indicates a serious illness or the possibility of its development. Most often we are talking about diabetes mellitus, in which high blood sugar levels are observed regularly. Less often – about iron deficiency in the body and anemia.

It is important to know: it is advisable even for healthy people 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.

If the level of glycated hemoglobin is elevated, this indicates a serious illness or the possibility of its development. Most often we are talking about diabetes mellitus, in which high blood sugar levels are observed regularly. Less often – about iron deficiency in the body and anemia.

The life span of red blood cells is about three months, this is the reason for the period during which the analysis for glycated hemoglobin shows the average level of sugar in the blood.Thus, glycated hemoglobin does not reflect single drops in blood sugar levels, but shows the general picture and helps to determine if the blood sugar level exceeded the norm sufficiently. Glycated hemoglobin is elevated for a long period of time. Therefore, it will not be possible to simultaneously reduce the level of glycated hemoglobin and normalize the indicators.

To normalize this indicator, you must lead a healthy lifestyle, follow the prescribed diet, take medications prescribed by your doctor or take insulin injections, and monitor your blood sugar level.

In diabetes, the norm of glycated hemoglobin is slightly higher than for healthy people, and an indicator of up to 7% is allowed. If, as a result of the analysis, the indicator exceeds 7%, this indicates that diabetes is not compensated, which can cause the development of serious complications.

Medical Center – Asclepius Glycosylated hemoglobin (HBA1C). Get tested in Vladivostok. Cost: 370 rubles.

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, it is a complex consisting of hemoglobin and glucose, which are irreversibly combined. 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 the serious complications against its background. With the help of the analysis for glycated hemoglobin in the blood, diabetes can be detected in the early stages, which helps to initiate timely and adequate treatment.

When is the research carried out?

• diabetes mellitus;
• suspicion of diabetes mellitus (severe thirst, frequent profuse urination, fatigue, blurred vision, increased susceptibility to infections).

Who orders the study?

Physician-therapist;

Doctor-endocrinologist.

Which biomaterial can be used for research

Venous blood

What the study is used for:

• preventive research;
• confirmation of the diagnosis of diabetes mellitus;
• monitoring of diabetes mellitus treatment;
• assessment of the prognosis of the disease and the risk of complications in diabetes mellitus.

Terms and conditions for obtaining results

Deadline – 1 business day.

It is possible to perform research on Cito (urgently).

Conclusion result

What does the result mean

Reference values:

4.8 – 5.9%

Interpretation of results:

Reasons for the increase:

• Disorders of carbohydrate metabolism: impaired glucose tolerance, prediabetes, diabetes;
• with an increase in the level of glycated hemoglobin, the risk of complications of diabetes mellitus also increases.

What can influence the result?

• Abnormal forms of hemoglobin, for example, sickle-shaped erythrocytes, underestimate the level of glycated hemoglobin;
• anemia, severe bleeding underestimate the results;
• iron deficiency, recent blood transfusion overestimate the test result.

What is HBA1C or glycated hemoglobin?

Glycated hemoglobin (glycosylated hemoglobin, HbA _1c ) is a standard laboratory test for assessing glycemic control over time.Glycated hemoglobin (HbA _1c ) consists of hemoglobin A (HbA) combined with glucose by a chemical bond and is a component of red blood cells (erythrocytes) that carry oxygen from the lungs to various organs of the body.

How often should glycated hemoglobin levels be monitored?

Red blood cells are produced in the bone marrow. They last approximately 120 days on average and are normally destroyed in the spleen.During the lifetime of erythrocytes (120 days), blood glucose is added to hemoglobin, so the level of glycated hemoglobin depends on the amount of glucose circulating in the blood for a given period of time, that is, on average for three months. Thus, according to the level of glycated hemoglobin, one can judge the average level of glycemia over the past three months and this indicator must be monitored once every three months.

Why is it important to measure the level of glycated hemoglobin?

The glycemic level fluctuates over a wide range during the day in people with type 1 and type 2 diabetes mellitus, therefore, single measurements of the glycemic level do not provide complete information on general control.Glycated hemoglobin is the average of the peaks and valleys in blood glucose levels over the previous two or three months.

Glycated hemoglobin values ​​may vary depending on the laboratory where the test is performed. If the test is performed in different laboratories, the values ​​may differ.

What should be the level of glycated hemoglobin?

By the level of glycated hemoglobin, you can judge the average level of blood glucose over the past three months.The table shows the ratio of the level of glycated hemoglobin and the average value of glycemia.

The target glycated hemoglobin level is determined by ONLY by the attending physician based on the presence of chronic complications and comorbidities in the patient.

What can influence the level of glycated hemoglobin?

There are a number of factors that can influence the level of glycated hemoglobin. In patients with the presence of these concomitant diseases, it is necessary to judge the compensation of diabetes mellitus by self-control of the glycemic level.

What is fructosamine?

The fructosamine test is similar to measuring the level of glycated hemoglobin and indicates the average level of glycemia over a shorter period of time: about 2-3 weeks.It is measured by the amount of glucose combined with blood proteins: the higher the glucose concentration, the higher the fructosamine will be. The advantage of this test is its cheapness and quickness of determination, but its disadvantage is its reliability. Target values ​​may vary depending on the laboratory and method of determining fructosamine. On average, less than 300 μmol / L is normal. This method can be used in the event of drastic changes in treatment and allows you to evaluate the effectiveness of the correction applied; during pregnancy; with a loss of red blood cells (blood loss, anemia), since the determination of the level of glycated hemoglobin will not be reliable.However, this method is not recommended for long-term glycemic control.

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, what is glycated hemoglobin in a blood test should be known to everyone, 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 cannot 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 current problems and opportunities through the eyes of a clinician

PEMtOUUM

R I s l

No. 6 (136) July-August, 2015

[CONSILIUM.ENDOCRINOLOGY)

Ya.A. PANASYUK, Ph.D. D., JSC “FIRMA GALEN”

Assessment of glycated hemoglobin (HbA1c): current challenges and opportunities through the eyes of a clinician

The level of glycemia is a key concept of laboratory research in diagnosing diabetes mellitus and monitoring the degree of its compensation. The task of the clinical diagnostic laboratory is to provide the attending physician with the most accurate indicators of the patient’s glycemic level, as well as provide complete information about the accompanying factors that affect its correct assessment.

In recent years, it has been shown that blood glucose cannot be a reliable indicator of glycemic levels for a number of reasons:

♦ significant natural changes in this indicator during the day. Even in healthy people, intraday fluctuations in glucose levels are 4-8 mmol / L;

♦ glucose in the blood reflects the “momentary” level of the patient’s glycemia and

does not provide information about the patient’s condition in retrospect;

♦ the need to “prepare” the patient for the study, which lies solely in the patient’s area of ​​responsibility.

The glycated hemoglobin test (HbA1c) has been proposed as an alternative diagnostic test. HbA1c reflects the average blood glucose level over the last 2-3 months (the half-life of erythrocytes): fluctuations in blood glucose levels during the day are leveled; glycemia is assessed over a wide time range; There is no need to “prepare” the patient for analysis. Strict standardization of methods for assessing glycated hemoglobin and the high quality of modern analytical systems have led to the inclusion of the HbA1c test in international and Russian standards both for the assessment of compensation and for the primary diagnosis of diabetes.

However, like any type of study, the HbA1c assessment has a number of analytical and clinical limitations that must be taken into account when interpreting the results obtained.

Analytical interference means that the measurement is incorrect: the result of the HbA1c test issued by the laboratory does not correspond to reality due to the fact that the analytical method used was not able to make an accurate assessment

HbAlc.The measurement accuracy of any analytical system can be estimated by the Bias (deviation of the measured value from the “correct” one), the coefficient of variation (CV% is the “non-reproducibility” of the results) and the list of interfering substances, in the presence of which the HbAlc measurement will be incorrect. For any commercial system used, you can obtain objective information about its accuracy from the annual renewed certificates of the international standardization programs IFCC and NGSP and on the official NGSP website: http: // www.ngsp.org.

What does a large coefficient of variation of an analytical system mean in practice? For example, if the patient’s true HbAlc value = 6.5%, then Device # 1 (with CV = 0.59%) will give a result of 6.5%, and Device # 2 (with CV = 4.17%) will give a result from 6.2 to 6.8%, and the assessment of the patient’s condition may be incorrect.

Clinical interference means misinterpretation of the result: the HbA1c result from the laboratory is correct, but due to the physiological or pathological characteristics of the patient himself, the target HbAlc value for this patient is not applicable.So, for example, in people with a heterozygous form of beta-thalassemia (a form of carriage without clinical manifestations), the average lifetime of erythrocytes is 90 days, and not 120, as in healthy people, and the HbAlc level will be 1% lower due to the shorter time of hemoglobin glycation …

The test for HbA1c has significant diagnostic advantages over the glucose test, however, when prescribing a measurement of HbA1c, you need to understand what kind of research method is used in the laboratory and whether it can be trusted, and if the analytical characteristics of the method allow you to give not only the “number” itself, but and the presence of possible interference, then interpret the result taking into account the influence of interfering factors.®

Ferritin

Ferritin

Ferritin – protein, in the form of which iron is mainly stored in the body. The most informative indicator of iron stores in the body, the main form of deposited iron. It is a spherical protein – apoferritin, in the core of which there is a complex of iron hydroxide and phosphate. One ferritin molecule can contain up to 4000 iron molecules.Ferritin is synthesized in the cells of the organs of the RES (reticuloendothelial system). Found in all body cells and body fluids. Serum ferritin contains 20-25% iron, and its concentration is a good indicator of iron stores in healthy people and in uncomplicated iron deficiency states. In addition to being used as an indicator of iron stores in the body, the determination of the concentration of ferritin is important for the differential diagnosis of iron deficiency anemia and anemia of chronic diseases (anemia accompanying infectious, rheumatic and tumor diseases).One of the main mechanisms of anemia of chronic diseases is the redistribution of iron into the cells of the macrophage system, which is activated during inflammatory (infectious and non-infectious) or tumor processes. Iron accumulates in macrophages in the form of ferritin, its transfer from ferritin to transferrin is disrupted, which entails a decrease in serum iron levels. In these conditions, the erroneous diagnosis of iron deficiency anemia and the appointment of iron preparations (parenteral) can lead to the development of hemosiderosis and the aggravation of the patient’s situation.Differential diagnosis of true and redistributive iron deficiency is possible only if the level of serum ferritin is determined. In oncopathology, especially tumor and metastatic lesions of the bone marrow, ferritin serves as a kind of tumor marker. Excessive iron intake after transfusion or hemodialysis leads to a temporary significant increase in serum ferritin levels. During pregnancy, ferritin levels may decline gradually, by 50% by week 20, and by 70% in the third trimester of pregnancy.In conditions of acute inflammation, an increased level of serum ferritin can not only reflect the amount of iron in the body, but also be a manifestation of an acute phase response, since ferritin is one of the acute phase proteins. However, if the patient does have iron deficiency, the acute phase increase in ferritin is not significant.

Preparation for examination

Do not eat for 12 hours before testing.
To obtain correct results, you must stop taking iron-containing drugs or warn your doctor about the appointment.If the patient has received a blood transfusion, the study should be postponed for several days.

Indications for research

Suspected deficiency or excess of iron in the body.

Suspected hemochromatosis.

Differential diagnosis of anemia.

Tumors.

Chronic infectious and inflammatory diseases.

While monitoring the effectiveness of the treatment of anemias and conditions accompanied by an overload of the body with iron.

Interpretation

Reference values:

total male norm-28: 365ng / ml

total female norm-5: 148 ng / ml
Increase in content:

Hereditary hemochromatosis. In this disease, too much iron is absorbed from food, which is deposited in various organs, causing them to be damaged.

Multiple blood transfusions, intramuscular iron administration, prescription of iron tablets.

Inflammations, eg upper respiratory tract infections, urinary tract infections, autoimmune diseases. Moreover, an increase in ferritin in the acute phase of inflammation can mask the existing iron deficiency.

Acute or chronic liver diseases.

Alcoholism.

Hemolytic anemias: associated with destruction of red blood cells, B12-deficiency anemia, thalassemia.

Hyperthyroidism – increased thyroid function.

Oncological diseases of the bone marrow, breast cancer, Hodgkin’s disease – a malignant neoplasm of lymphoid tissue.Ferritin levels will be significantly increased.
Decrease in content:
Iron deficiency, including latent. Decreased ferritin usually indicates iron deficiency anemia.

Third trimester of pregnancy. A decrease in the amount of iron in this case is normal

Results may be affected

Falsely increased results can be caused by:

fasting, alcohol, estrogens, oral contraceptives, iron supplements,

hemolysis.