What is the HbA1c test and how does it measure average blood sugar levels. Why is HbA1c important for diagnosing and monitoring diabetes. How does glycation affect hemoglobin and what are the implications for long-term health.

The Discovery and Significance of HbA1c

Hemoglobin A1C (HbA1c) was first identified in the late 1960s during research on human hemoglobin A (HbA). Scientists noticed variations in hemoglobin, which they labeled HbA1a, HbA1b, HbA1c, and so on. These variants exhibited different properties from normal hemoglobin, prompting further investigation into their biological roles.

By the late 1970s, researchers had determined that HbA1c was formed through glycation – the chemical bonding of glucose to HbA. This discovery led to an important realization: individuals with higher blood glucose levels, particularly those with diabetes, tended to have higher levels of HbA1c.

Why is HbA1c significant for diabetes management?

• It reflects average blood glucose levels over the past three months
• Higher HbA1c levels correlate with earlier and more severe diabetic complications
• It provides a more comprehensive picture of glucose control compared to daily blood sugar tests

The Landmark Diabetes Control and Complications Trial (DCCT)

The DCCT, conducted from 1983 to 1993, was a pivotal study that established HbA1c as a primary biomarker for diabetes management. This extensive research followed 1,441 individuals with Type 1 diabetes, comparing conventional and intensive therapy approaches.

Key findings of the DCCT:

1. Participants receiving intensive therapy achieved lower HbA1c levels
2. Lower HbA1c levels correlated with reduced rates of microvascular complications
3. Complications such as retinopathy, nephropathy, and neuropathy were less prevalent in the intensive therapy group

These results underscored the clinical importance of HbA1c testing and its potential to guide diabetes treatment strategies.

Standardization Efforts for HbA1c Testing

Following the DCCT, researchers faced a new challenge: standardizing HbA1c testing across laboratories and countries. Inconsistencies in test results were attributed to various chemical techniques, each with unique definitions and error types.

To address this issue, two groups spearheaded a collaborative effort:

• The National Glycohemoglobin Standardization Program
• A working group at the International Federation of Clinical Chemistry and Laboratory Medicine

Their efforts, spanning two decades, resulted in the worldwide harmonization and standardization of HbA1c tests. This achievement has greatly improved the reliability and comparability of HbA1c results across different healthcare settings.

The Science Behind HbA1c: Understanding Glycation

The HbA1c test measures glycated hemoglobin in the bloodstream. But what exactly is glycation, and how does it relate to blood glucose levels?

What is glycation?

Glycation, also known as the Maillard reaction, caramelization, or “browning” reaction, is a natural process that occurs when glucose molecules bond with proteins in the body. This process happens spontaneously, without the need for enzymes or energy input.

How does glycation affect hemoglobin?

In the context of HbA1c, glycation occurs when glucose molecules bond with the amino acid valine at the end of hemoglobin chains. This forms an irreversible covalent bond, creating glycated hemoglobin.

The percentage of glycated hemoglobin directly correlates with average blood glucose levels over the past 2-3 months. This is because red blood cells, which contain hemoglobin, typically have a lifespan of about 120 days.

Are there any health implications of glycation beyond blood glucose measurement?

Yes, glycation has broader health implications:

• It’s associated with the aging process, contributing to the formation of wrinkles and cataracts
• Each glycation reaction produces an oxygen radical, which can cause cellular damage if not neutralized by antioxidants
• Over time, accumulated oxidative stress from these reactions can lead to organ damage

Interpreting HbA1c Results: What Do the Numbers Mean?

HbA1c results are typically reported as a percentage in the United States, Canada, and Japan. For example, an HbA1c result of 5% indicates that 5% of the hemoglobin molecules in the body have glucose bonded to them.

What are the target HbA1c levels for different groups?

• For individuals without diabetes: below 5.7%
• Prediabetes range: 5.7% to 6.4%
• Diabetes diagnosis: 6.5% or higher
• Target for most adults with diabetes: below 7% (though individual targets may vary based on health status and other factors)

It’s important to note that these ranges may differ slightly depending on the specific guidelines used in different countries or healthcare systems.

The Role of HbA1c in Diabetes Diagnosis and Management

Today, the HbA1c test plays a crucial role in both the diagnosis and management of diabetes. Its ability to provide a long-term view of blood glucose control makes it an invaluable tool for healthcare providers and patients alike.

How is HbA1c used in diabetes diagnosis?

The HbA1c test can be used to diagnose both diabetes and prediabetes. Unlike fasting glucose tests or oral glucose tolerance tests, the HbA1c test doesn’t require fasting or any special preparation, making it more convenient for patients.

What role does HbA1c play in ongoing diabetes management?

For individuals with diabetes, regular HbA1c testing helps:

• Monitor the effectiveness of current treatment plans
• Guide adjustments to medication, diet, and lifestyle interventions
• Assess the risk of developing diabetes-related complications
• Set and track progress towards glucose control goals

Typically, healthcare providers recommend HbA1c testing every 3-6 months for people with diabetes, depending on their individual circumstances and how well their blood glucose is controlled.

Limitations and Considerations of HbA1c Testing

While the HbA1c test is a powerful tool in diabetes care, it’s important to understand its limitations and potential confounding factors.

What conditions can affect HbA1c results?

Several factors can influence HbA1c results, potentially leading to inaccurate readings:

• Anemia or other blood disorders
• Recent blood loss or transfusions
• Certain medications
• Kidney or liver disease
• Genetic variations in hemoglobin

In these cases, healthcare providers may need to rely on other methods of assessing blood glucose control, such as fructosamine tests or continuous glucose monitoring.

How does HbA1c compare to other glucose monitoring methods?

While HbA1c provides valuable information about long-term glucose control, it doesn’t capture day-to-day fluctuations or patterns in blood sugar levels. For this reason, it’s often used in conjunction with other monitoring methods:

• Self-monitoring of blood glucose (SMBG): Provides real-time glucose readings and helps identify immediate trends
• Continuous glucose monitoring (CGM): Offers detailed insights into glucose patterns and variability throughout the day and night
• Fructosamine tests: Measure glycated proteins over a shorter timeframe (2-3 weeks), which can be useful for monitoring rapid changes in glucose control

By combining these different approaches, healthcare providers and patients can gain a comprehensive understanding of glucose control and make informed decisions about diabetes management.

Future Directions in HbA1c Research and Clinical Applications

As our understanding of diabetes and glycemic control continues to evolve, so too does the role of HbA1c in research and clinical practice. Several exciting areas of investigation are currently underway.

What new developments are emerging in HbA1c testing?

• Point-of-care HbA1c testing: Rapid, in-office tests that provide results within minutes, enabling immediate treatment decisions
• Non-invasive HbA1c measurement: Research into methods that don’t require blood samples, such as spectroscopic techniques
• Improved standardization: Ongoing efforts to further refine and harmonize HbA1c testing across different laboratories and technologies

How might HbA1c be used beyond diabetes management in the future?

Researchers are exploring the potential of HbA1c as a biomarker for other health conditions and outcomes:

• Cardiovascular risk assessment: HbA1c levels may provide insights into cardiovascular health, even in individuals without diabetes
• Cognitive function: Some studies suggest a link between HbA1c levels and cognitive performance or risk of dementia
• Cancer risk: Emerging research is investigating potential associations between HbA1c and certain types of cancer

As these areas of research progress, we may see expanded applications for HbA1c testing in preventive medicine and personalized healthcare strategies.

What challenges remain in HbA1c research and clinical use?

Despite significant advances, several challenges persist in the field of HbA1c testing and interpretation:

• Addressing racial and ethnic differences in HbA1c: Some studies suggest that HbA1c levels may vary between different ethnic groups, even at similar blood glucose levels
• Improving accessibility: Ensuring that high-quality HbA1c testing is available in resource-limited settings
• Integrating HbA1c with other biomarkers: Developing more comprehensive models that combine HbA1c with other indicators of metabolic health
• Understanding the impact of emerging diabetes therapies on HbA1c: As new treatments become available, their effects on HbA1c and its interpretation need to be studied

Addressing these challenges will be crucial for maximizing the utility of HbA1c testing and improving diabetes care worldwide.

Empowering Patients: Understanding and Acting on HbA1c Results

While HbA1c is a powerful tool for healthcare providers, it’s equally important for patients to understand their results and how they can use this information to improve their health.

How can patients use their HbA1c results to improve diabetes management?

• Set realistic goals: Work with healthcare providers to establish personalized HbA1c targets
• Track progress: Use regular HbA1c tests to monitor long-term improvements in glucose control
• Identify areas for improvement: High HbA1c results may indicate a need for changes in medication, diet, or lifestyle
• Stay motivated: Seeing improvements in HbA1c can provide positive reinforcement for healthy behaviors

What lifestyle factors can influence HbA1c levels?

Patients can take an active role in managing their HbA1c levels through various lifestyle interventions:

• Dietary choices: Emphasizing foods with a low glycemic index and controlling portion sizes
• Regular physical activity: Exercise helps improve insulin sensitivity and glucose uptake
• Stress management: Chronic stress can affect blood glucose levels, so stress-reduction techniques may be beneficial
• Consistent medication adherence: Taking prescribed medications as directed is crucial for maintaining stable blood glucose levels
• Adequate sleep: Poor sleep quality or duration can negatively impact glucose metabolism

By focusing on these areas, patients can work towards improving their HbA1c results and overall health outcomes.

How often should patients have their HbA1c tested?

The frequency of HbA1c testing can vary depending on individual circumstances:

• For people with well-controlled diabetes: Every 6 months
• For those with recent changes in treatment or difficulty meeting targets: Every 3 months
• For individuals without diabetes but at high risk: Annually as part of routine health screening

Patients should discuss the appropriate testing schedule with their healthcare provider, as individual needs may vary based on factors such as overall health status, diabetes type, and treatment regimen.

The Global Impact of HbA1c Testing on Diabetes Care

The widespread adoption of HbA1c testing has significantly transformed diabetes care on a global scale. Its impact extends beyond individual patient care to influence public health policies, research priorities, and healthcare resource allocation.

How has HbA1c testing improved diabetes management worldwide?

• Standardized diagnosis: The use of HbA1c for diabetes diagnosis has helped create more consistent criteria across different countries and healthcare systems
• Enhanced treatment guidelines: HbA1c targets have been incorporated into international diabetes management guidelines, promoting evidence-based care
• Improved population health monitoring: Regular HbA1c testing allows for better tracking of diabetes trends and the effectiveness of public health interventions
• Facilitated research: Standardized HbA1c measurements have made it easier to conduct and compare diabetes research studies across different populations and regions

What challenges exist in implementing HbA1c testing in resource-limited settings?

While HbA1c testing has become a cornerstone of diabetes care in many parts of the world, significant challenges remain in making it universally accessible:

• Cost: HbA1c testing can be expensive, particularly in low- and middle-income countries
• Equipment and training: Specialized laboratory equipment and trained personnel are required for accurate HbA1c testing
• Quality control: Maintaining consistent test quality across different settings can be challenging
• Cultural and language barriers: Educating patients about HbA1c and its importance may be difficult in diverse cultural contexts

Addressing these challenges is crucial for ensuring equitable access to high-quality diabetes care worldwide.

What initiatives are underway to expand access to HbA1c testing globally?

Several organizations and initiatives are working to improve global access to HbA1c testing:

• Development of low-cost, point-of-care HbA1c tests suitable for use in resource-limited settings
• Training programs to increase the number of healthcare workers skilled in HbA1c testing and interpretation
• International collaborations to establish and maintain quality control standards for HbA1c testing
• Advocacy efforts to include HbA1c testing in national health insurance schemes and essential diagnostics lists
• Research into alternative biomarkers that may be more suitable for certain populations or settings

These efforts aim to ensure that the benefits of HbA1c testing can be realized by people with diabetes around the world, regardless of their geographic location or economic status.

What is HbA1c, and why does it matter?

Unlike other blood sugar tests, HbA1c reflects your average glucose levels over time. Here’s why it’s a useful marker for minding blood sugar.

The HbA1c test measures your average blood sugar over the past three months. It is a simple blood test frequently used to screen for and diagnose diabetes and monitor treatment.

HbA1c (also known as A1c) was first discovered in the late 1960s by researchers studying human hemoglobin A (HbA)—an iron-containing oxygen-carrying protein found in red blood cells. They noticed that HbA sometimes appeared in alternate forms, which the researchers designated HbA1a, HbA1b, HbA1c, and so on. These hemoglobin variants had different physical and chemical properties from normal hemoglobin, raising questions about their biological purpose.

By the late 1970s, researchers focused on HbA1c determined that it was formed by glycation—the chemical bonding of a glucose molecule to HbA. People with higher blood glucose levels (such as people with diabetes) were found to have higher levels of HbA1c. Excitement began to build around HbA1c as a marker of high blood sugar because people with higher HbA1c levels developed earlier and more severe diabetic complications. This suggested that doctors could use HbA1c to track how effectively people with diabetes control their blood glucose.

But it wasn’t until the landmark Diabetes Control and Complications Trial (DCCT) that HbA1c was firmly established as an important primary biomarker for diabetes management. The study, which ran from 1983 to 1993, followed 1,441 people with Type 1 diabetes. Participants were given either conventional therapy (one daily blood glucose measurement and 1-2 daily insulin injections) or intensive therapy (4+ daily blood glucose measurements and 3+ daily insulin injections or the use of an insulin pump). People in the intensive therapy group ultimately had lower HbA1c levels (indicating better blood glucose control) and lower rates of microvascular (small blood vessel) complications, such as retinopathy (eye damage that can cause vision loss), nephropathy (kidney damage that can lead to dialysis), and neuropathy (peripheral nerve damage that can lead to amputation).

After affirming the clinical importance of HbA1c testing, researchers faced a new challenge: standardization. By the early 1990s, it had become clear that test results varied significantly between different laboratories and countries. This inconsistency was due to the wide range of chemical techniques used to measure HbA1c—each of which defined the chemical target differently and suffered from unique error types. Laboratories and manufacturers also lacked a primary reference material (i.e., a pure sample of HbA1c to calibrate tests and machinery).

To solve this problem, two groups—the newly-formed National Glycohemoglobin Standardization Program and a working group at the International Federation of Clinical Chemistry and Laboratory Medicine—spearheaded a collaborative, multinational effort. These efforts (which unfolded over the next two decades) were successful, leading to the worldwide harmonization and standardization of HbA1c tests.

Today, clinicians use HbA1c (in combination with other tests) to diagnose diabetes and prediabetes and to monitor blood glucose management in people with diabetes.

What does HbA1c Measure?

The HbA1c test measures glycated hemoglobin in your bloodstream. In the US, Canada, and Japan, you’ll see this number as a percentage. For instance, an HbA1c test result of 5% would mean that 5% of the HbA molecules in your body have a glucose molecule bonded (or glycated) at Amino Acid #1.

Glycation, also known as the Maillard or the caramelization or “browning” reaction, occurs normally. It serves no biological purpose otherwise; it is simply a chance reaction between glucose and proteins in your body. It occurs in every organ, every day. It doesn’t need an enzyme or energy to occur. It’s also called the “aging” reaction—the reason you develop wrinkles and cataracts. Hemoglobin is made of four chains of amino acids folded together in a complex shape. When glucose encounters one of these chains ending with the amino acid valine, the two molecules form an irreversible covalent bond. Also, every time this Maillard reaction occurs, an oxygen radical (like hydrogen peroxide) is formed, which can cause cellular damage if not captured and detoxified by an anti-oxidant, such as Vitamin C or glutathione. Over time, these oxygen radicals (termed “oxidative stress”) can cause whole organs to fail.

The more glucose you have in your bloodstream, the more frequently these bonds occur and the higher your HbA1c level. But there is an upper limit on how high your HbA1c level can rise because your body constantly replaces red blood cells, which typically live for around 120 days. At that point, they are filtered by the spleen and broken down (along with any HbA1c they contain).

This 120-day lifespan (and the fact that glycation is a relatively slow chemical reaction) means that HbA1c levels act as a long-term biomarker for blood glucose levels. Unlike direct measurements of blood glucose (which can vary widely from minute to minute, hour to hour, and day to day), HbA1c levels reflect your average glucose levels over a three-month timeframe.

Why Would I Get HbA1c Tested?

Doctors generally test HbA1c for three reasons:

1. Diabetes screening.  The American Diabetes Association recommends that all people aged 45 and older get an HbA1c test, even if they have no symptoms or risk factors for diabetes.
2. Diabetes diagnosis. If you already have symptoms of diabetes or other risk factors (e.g., high blood pressure or first-degree relatives with diabetes), your doctor may use an HbA1c test to make an official diagnosis.
3. Diabetes management. If you have been diagnosed with diabetes, your healthcare provider may use periodic HbA1c tests to gauge how well you control your blood sugar.

In each case, the HbA1c level infers your average blood glucose over the prior three months. This result provides important information that alternative tests can’t. For instance, a fasting plasma glucose test (which requires patients to fast for 8-10 hours before the blood draw) only reflects your blood sugar at a single moment. Researchers have argued that these “snapshot” tests, even when performed twice, are less reliable than the HbA1c test in diagnosing chronically elevated blood glucose levels. This is partly due to “acute perturbations” — factors like stress, smoking, and diet that can influence a simple blood glucose reading on the day of your test.

The same is true of the oral glucose tolerance test (OGTT). In this test, you drink a large, sugary beverage. After a two-hour wait, doctors measure your blood glucose to see how effectively your body has cleared that glucose from the bloodstream. A healthy person’s blood glucose levels will spike at 30-60 minutes, followed by a fairly prompt decline by 120 minutes. In a person with insulin resistance or diabetes, however, blood glucose levels will remain high for an extended period. Like the fasting plasma glucose (FPG) test, this is a “snapshot” test that can be impacted by stress, sleep, and eating before the test, as well as the rate at which your stomach empties and your level of physical activity level in the preceding days.

The FPG and OGTT tests can also be swayed by laboratory errors that don’t affect HbA1c tests. Furthermore, they require 8-14 hours of fasting before the test (an instruction that some people may not successfully follow). For all these reasons, the HbA1c test is more reproducible than the FPG or the OGTT. If a person takes the HbA1c test twice, their results will likely be fairly close. If the same person takes an FPG or an OGTT, their results are less likely to match. For now, the OGTT is still considered the “gold standard” of diabetes diagnosis—but there is debate around this point.

Some authors argue that HbA1c is generally a more reliable indicator of chronic blood glucose elevation. Some recent research supports this view, such as a 2017 study of 3326 people in Singapore, which found that the HbA1c test outperformed the OGTT in classifying people with diabetes. Another study of 200 people in Hong Kong found that HbA1c was better for diagnosing diabetes and tracking its progression than the FPG test. And a 2012 study of 77 overweight or obese African American women and 5 African American men found that high HbA1c was superior to FPG testing in making a positive diabetes diagnosis (though a low HbA1c did not rule out diabetes).

Conversely, other research has reached the opposite conclusion. For instance, a 2012 study of 844 people in Italy at risk of Type 2 diabetes found that the OGTT was a better predictor of prediabetes and diabetes than HbA1c testing. Similarly, a 2019 study of 512 high-risk Thai patients found that HbA1c testing is “much inferior” to the OGTT as a diabetes screening tool. Finally, a 2015 study of 98 obese US youth found that the OGTT and HbA1c testing performed equally well. Again, this is an area of ongoing discussion and research, and the mainstream perspective may shift in the future.

It’s important to note that the HbA1c test has some limitations. For instance, medical conditions that shorten the lifespan of your red blood cells (such as the sickle cell trait) can produce a falsely low A1c reading. This is because your red blood cells quickly cycle out, giving hemoglobin glycation less time to occur. In this situation, an A1c test could incorrectly suggest that your glucose levels have been normal, even if they have been dangerously high. That’s why a diabetes diagnosis typically requires multiple types of glucose testing.

Not also that HbA1c only measures glucose fluctuations; it does not measure fructose variations in the blood, as fructose is more likely to bind to HbA at positions #66 and #110 rather than at position #1. This limits the use of HbA1c to diagnose or monitor sugar overconsumption.

A1c also captures only a long-term trend, not a picture of your daily glucose fluctuations (or glycemic variability), which can also impact your health.

How Do I Get HbA1c Tested?

The HbA1c test is not part of a standard blood chemistry panel. Your doctor is only likely to order it if they’re screening, diagnosing, or treating you for diabetes. But even if you don’t fit into one of those categories, you can still request an HbA1c test from your doctor. The HbA1c will start to rise at the onset of metabolic dysfunction, and many doctors use it as an early indicator. If your provider agrees that a test is appropriate, they will take a blood sample in their office or refer you to an outside laboratory. The test results typically come back in a day or two.

If your doctor doesn’t want to order an HbA1c test, you can order one directly from a retail laboratory. These tests usually cost $30-$50. Alternatively, you can order an at-home HbA1c test for the same price. To complete this test, you’ll submit a small blood sample by mail and get your results within a week. There are also at-home HbA1c electronic test devices. These are a little pricier (around $75) but give instant results and can be reused several times.

There is no way to infer your HbA1c level without testing it directly. However, every 30 mg/dL increase in average blood glucose correlates with an increase of HbA1c by approximately 1.0%.

What Are Optimal Ranges of HbA1c?

There is still some debate around ideal HbA1c levels. According to the American Diabetes Association, HbA1c results fall into three categories:

• Less than 5.7% signifies normal and healthy metabolism
• 5.7% to 6.4% signifies prediabetes
• 6. 5% or higher signifies full-blown diabetes

If you’ve recently taken an HbA1c test and are seeing higher results than you expected, don’t panic—there are several caveats to consider as you interpret your data. First, note that these tests have roughly a 0.4% margin of error. An HbA1c result of 6.0% may therefore signify prediabetes or be erroneously skewed upward from an HbA1c level of 5.6%.

Second, there may be racial, ethnic, age, and gender differences to account for when measuring HbA1c. Studies have shown that Black, Indigenous, Hispanic, and Asian people tend to have slightly higher HbA1c levels than white people. Research suggests that this is not due to higher underlying blood glucose levels but rather to racial/ethnic differences in red blood cell lifespan and other factors that affect hemoglobin glycation. In other words, the “safe” ceiling for HbA1c may be higher among people of color. The American Diabetes Association 2020 Standards of Care document states that “HbA1c levels may vary with race/ethnicity independently of glycemia. ” Some studies have also found that HbA1c levels tend to rise with age and run higher in men than women.

Finally, HbA1c results can be falsely raised or lowered by various factors. For instance, anemia, kidney dysfunction, and high triglycerides can all spike your HbA1c. Conversely, pregnancy, an enlarged spleen, and high vitamin E intake can all lower your HbA1c.

For these reasons, working closely with your healthcare provider when interpreting your HbA1c test results is essential. That said, elevated levels are associated with several severe health conditions. High blood glucose levels can damage your eyes, kidneys, heart, nerves, and blood vessels. Prediabetes puts you at risk for vascular disease, cancer, and dementia, whether or not it develops into full-blown diabetes. And even in people without diabetes, high HbA1c levels indicate metabolic dysfunction and are linked to heart disease and dementia.

It’s also important to note that some metabolic health experts, including many Levels advisors, are more conservative in their recommendations than the American Diabetes Association (ADA). While the ADA sets 5.7% as the safe ceiling for normal A1c levels, these specialists recommend 5.5% or even 5.0% as the optimal upper limit.

Based on their collective input, we suggest you aim for a level under 5.5%, noting that some experts say 5.0% is even better.

Managing Diabetes: What Is HbA1c and What Is a Normal Level?

Nearly half of all Americans have some form of diabetes, whether they know it or not. 

In a given year, more than 37 million diabetic Americans have already been diagnosed, 8.5 million remain undiagnosed, and another 96 million are living with prediabetes,¹² an earlier stage on the disease spectrum that is characterized by higher-than-normal blood sugar levels.

If left untreated, both prediabetes and diabetes can lead to serious health complications, including heart disease, Alzheimer’s, nerve and kidney damage, certain cancers and premature death. In some younger women, elevated HbA1c is also associated with polycystic ovarian syndrome (PCOS). ³

Despite the high rates of diagnosis, there’s good news: if you have prediabetes, and possibly even if you have diabetes, you may be able to improve your blood sugar level with healthy lifestyle changes. But before you can reduce your blood sugar level, you’ll need to know what it is. This is where hemoglobin A1c (also known as HbA1c, or sometimes just A1c) testing comes in. 

If your healthcare provider suspects that you’re at risk for diabetes, they may suggest HbA1c testing, as it can help diagnose and manage both prediabetes and diabetes. 

What is an HbA1c test and how does it work?

An HbA1c test is a simple blood test that measures your average blood glucose level over a period of time by looking at hemoglobin.

Hemoglobin is a protein found in red blood cells; its role is to carry oxygen from your lungs to the rest of your body. When glucose builds up in the bloodstream, it binds to hemoglobin and creates glycated (i.e., saturated with glucose) hemoglobin proteins. HbA1c testing measures the percentage of glycated hemoglobin proteins in your blood.⁴

Here’s the extra-cool part: red blood cells live for about three months in the bloodstream, so an HbA1c test gives a three-month average of your blood sugar level.⁵ 

While there are other methods of measuring glucose that can show a snapshot of blood sugar, HbA1c provides a more comprehensive picture. There’s no specific prep required for an HbA1c test, but since it’s often combined with other types of tests, you might end up fasting before giving your blood sample.

There are several types of diabetes — type 1, type 2 and gestational diabetes (diabetes that happens during pregnancy) being the main ones. Of these, type 2 is the most common by far, affecting nine out of 10 Americans with diabetes.⁶ Additional tests (such as an oral glucose tolerance test) may be needed to confirm a diagnosis.

Various health organizations, like the American Diabetes Association (ADA), International Expert Committee (IEC) and the World Health Organization (WHO), recommend using HbA1c to help with the diagnosis of diabetes, but the test can also be used proactively, too.  

For people with an increased risk or family history of diabetes, and for anyone who wants a baseline before making positive lifestyle changes, HbA1c testing is a useful self-monitoring tool that shows your body’s ability to handle glucose.

What’s a normal HbA1C level?

Your HbA1C level can give you an idea of whether you have normal blood sugar, prediabetes or diabetes. Results are reported as a percentage — the higher the percentage, the higher your blood sugar over the last several months. 

Here are the HbA1c thresholds used for diagnosing diabetes and prediabetes:⁷

• Normal: Below 5.7%
• Prediabetes: Between 5.7% and 6.5%
• Diabetes: 6.5% or higher

What does it mean if your HbA1c is high?

In simple terms, a high HbA1c level means you have poor blood glucose control, in other words too much sugar in your bloodstream. That said, one test isn’t enough for an official diagnosis of diabetes or prediabetes — the test should be repeated to confirm that results are consistent.  

What are the symptoms of high HbA1c?

Symptoms of HbA1c levels above 6.5% are the same as symptoms of hyperglycemia or diabetes. Common signs associated with an increase of levels of HbA1c include:⁸

• Increased thirst
• Frequent urination
• Blurred vision
• Fatigue

Just keep in mind, if your level of HbA1c is in the prediabetes range (5.7% to 6.4%), you may not experience any noticeable symptoms. So, if you are at risk for diabetes (obesity, high blood pressure, history of heart disease, lack of physical activity), it’s particularly important to keep tabs on your HbA1c levels.⁹

How are HbA1c tests used to monitor and manage diabetes?

HbA1c tests are often used by diabetic patients as a monitoring tool that can help with glycemic control. Typically, they’re repeated every three to six months.

According to the American Diabetes Association, the target range for most people with diabetes is an HbA1c of less than 7%, but the lower, the better. ¹⁰ Higher numbers mean increased risk of diabetes complications.

Testing HbA1c levels regularly can help patients with diabetes determine if their lifestyle changes are working, and when they need to adjust their treatment plan to reduce the risk of complications.

How quickly can you improve your HbA1c levels?

Because red blood cells live an average of three months, you could theoretically notice a decrease in your levels within three months of adopting consistent healthy lifestyle changes. How much (and how quickly) you lower your HbA1c will depend on various factors, like your diet and physical activity levels.

“I saw a patient with an HbA1c of more than 12, which is an extremely destructive number, get down to 8.5 in three months, and then to 6.5 in three more months…I’ve also seen plenty of people in the six-plus area get into the fives in three months,” says Dr. Ford Brewer, a board-certified preventive and occupational medicine specialist. 

Keep in mind, though, reducing levels to this extent takes work.  

“These drastic improvements require very significant lifestyle changes,” says Dr. Brewer. “This typically means going from a typical standard American diet to a very low-carb or keto diet and adding in a new exercise routine.”

Here are some proven ways to lower blood sugar and hit HbA1c targets over time:

1. Scale back on carbs and added sugars.¹¹
2. Eliminate refined carbs and sugars (think: breads, cereals, pasta, sweets). 
3. Mindfully consume high-glycemic fruits, whole grains and legumes.¹² 
4. Pair higher glycemic foods with a source of protein and fat to minimize blood sugar spikes.¹³
5. Test your blood sugar with a glucometer after meals to understand what specific carb sources you may tolerate best.
6. Aim for seven to nine hours of consistent, high-quality sleep a night.¹⁴¹⁵

What are the shortcomings of HbA1c testing? 

An HbA1c test isn’t a total picture of metabolic health or glycemic control. For example, it’s possible to have a normal HbA1c even if you have elevated insulin. Insulin, a hormone released by the pancreas in response to eating carbohydrates and sugars, helps usher sugar into cells where it can be used for energy. High insulin levels in the bloodstream mean your body is working extra hard to maintain normal blood sugar levels; over time, this can progress to insulin resistance —which is also linked to cardiovascular disease¹⁶ — and to diabetes. 

According to the National Institute of Diabetes and Digestive and Kidney Diseases, anything that changes the lifespan of red blood cells, including recent blood loss, sickle cell disease, blood transfusion, pregnancy, liver and kidney disease, iron deficiency and anemia can affect HbA1c results and lead to falsely elevated or lowered results.¹⁷

In his practice, Dr. Brewer sees diabetic patients coming in with HbA1c values in the 5% range, or even lower. 

“Their doctors tell them, ‘There’s no way you have diabetes. You don’t even have prediabetes,’” he says. “Then the patients shows the doctor their oral glucose tolerance test or insulin survey test and their blood sugars, when challenged, are off the charts. ” 

Dr. Brewer notes that these patients typically eat very low-carb diets, which explains their low HbA1c. So, while it’s great if your HbA1c is in the target range and you’re eating a diet that makes that range attainable, Dr. Brewer cautions that HbA1c should be considered the bare minimum of diabetes screening tests. 

If you’re concerned about your diabetes risk, Dr. Brewer suggests asking your doctor for the more comprehensive oral glucose tolerance once a year, or any time you gain 10 pounds or more. For this test, you’ll be given a strong glucose drink, then have your blood drawn at various intervals to measure your body’s response to the sugars. 

Summary

Whether you’re already diabetic or just trying to be proactive in maintaining optimal health and blood sugar, an HbA1c test is an extremely valuable tool. When you notice levels creeping up, it can be a great motivator to change your habits or start working with a healthcare professional to bring those levels down. Just remember that an HbA1c test is only one part of the picture, so if you want a complete assessment of your glycemic control and overall health, work with your doctor to determine if additional testing is needed.

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Hemoglobin (HbA1c) and other markers of diabetes

Hemoglobin (HbA1c) and other markers of diabetes – Product Information Hytest

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Diabetes is one of the most serious health problems of the 21st century and one of the leading causes of death in the world. Diabetes causes significant health costs due to the complications often associated with the disease. These complications include coronary and peripheral vascular disease, diabetic neuropathy, amputations, kidney failure, and blindness.

Diabetes is one of the most serious health problems in the 21st century.

Hytest offers antibodies and antigens for the development of immunoassays for the detection of various markers of diabetes such as hemoglobin (HbA1c), C-peptide and insulin.

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Glycated hemoglobin HbA1c

Several studies have shown that glycated hemoglobin (HbA1c) provides a better estimate of mean hyperglycemia than conventional blood glucose measurements. Measurement of HbA1c in the diagnosis of type 2 diabetes is recommended by the American Diabetes Association, the World Health Organization and the International Diabetes Federation.

Calibration curve for fluorinated HbA1c immunoassay. Capture antibody: anti-HbA10 (Cat. No. 4HH0). Detection antibodies: anti-HbA1c (cat. no. 4HA1). Calibrator: native HbA1c.

Proinsulin, insulin and C-peptide

Proinsulin, insulin and C-peptide assays are widely used to monitor hypoglycemia, pathogenesis and treatment of diabetes mellitus. Insulin is synthesized in the pancreas from its precursor proinsulin. During this process, proinsulin is proteolytically cleaved into three peptides: the A- and B-chain and the C-peptide. The A and B chains are covalently linked by disulfide bonds to form mature insulin.

Analysis of the synthesis and processing of proinsulin, as well as the release of insulin and C-peptide is very important for a better understanding of disorders of carbohydrate metabolism. Insulin, proinsulin, and C-peptide tests are widely used to monitor hypoglycemia, pathogenesis, and treatment of diabetes mellitus.

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Medical center “CONSULTANT” – Glycated hemoglobin

The measurement of glycated hemoglobin is carried out on the ADAMS Automatic Glycated Hemoglobin Analyzer, Arkray, Japan. Arkray equipment and reagents have been introduced into the world endocrinological practice and are successfully used in the leading clinical diagnostic laboratories of the Russian Federation. Analyzer Adams HA-8180V, Arkray is the most accurate analyzer in the world, which is confirmed by international quality certificates IFCC and NGSP, which Arkray receives annually.

Urgency of the problem
Currently, there are only 366 million patients with DM on our planet (7% of the world’s population). Experts of the World Diabetes Federation predict that the number of patients with diabetes by 2030 will increase by 1.5 times and reach 552 million people, i.e. every 10th inhabitant of the planet will get sick.

In modern endocrinological practice, the measurement of glycated hemoglobin (HbA1c) is an integral part of diagnosis and treatment selection. The determination of glycated hemoglobin is recognized as necessary to control the course of diabetes mellitus by the World Health Organization, and should be carried out once every 3 months in order to determine the effectiveness of treatment and assess the risk of complications.

The American Diabetes Association recommends that A1c be stable < 7.0%, tested and treated:
– Every 3-6 months (if A1c is stable < 7.0%)
– Every 2-3 months (if A1c is 7.0% – 9.0%)
– Every month (A1c > 9.0% until control is reached)

Benefits of HbA1c as a marker of early carbohydrate metabolism disorders:

1. More reliable glycemic indicator
2. Allows you to effectively assess the risk of complications
3. Test standardized
4. HbA1c is more stable as an analyte
5. Low variability
6. No need for frequent measurements, fasting measurements
7. The impact of stress on the result is minimal
8. Recommended for use in choice of therapy

The HbA1c value reflects the average level of glucose concentration in the patient’s blood during the 2-3 months preceding the study. Measurement of HbA1c allows in most cases to do without a glucose load test, which is not always safe for the patient and cannot be performed if the fasting blood glucose level exceeds 7.0 mmol / l.

Strict glycemic control is essential to reduce the risk of diabetes complications. Strict glycemic control, initiated immediately after the diagnosis of diabetes, can delay the development of microvascular and macrovascular diseases.

Quantification based on high performance liquid chromatography (HPLC) is recommended for the determination of hemoglobin fractions.

Glycated hemoglobin measurement is performed on the ADAMS Automatic Glycated Hemoglobin Analyzer, Arkray, Japan. Arkray equipment and reagents have been introduced into the world endocrinological practice and are successfully used in the leading clinical diagnostic laboratories of the Russian Federation. Analyzer Adams HA-8180V, Arkray is the most accurate analyzer in the world, which is confirmed by international quality certificates IFCC and NGSP, which Arkray receives annually.

Who should be tested for Hb1c?

• Diabetes monitoring
• Screening: people over 40 every 3 years
• Population over 40 with 1 or more risk factors (obesity BMI ≥30 kg/m2; hypertension)
• People with cardiovascular disease (myocardial infarction, angina pectoris, stroke or peripheral vascular disease)
• Obese women with polycystic ovary syndrome
• People taking antipsychotics (some drugs, especially glucocorticoids and antipsychotics, can interfere with glucose metabolism and increase the risk of diabetes)
• Women planning a pregnancy and at 24-28 weeks of gestation and 30-32 weeks in case of polyhydramnios during pregnancy)
• Women who had gestational diabetes (GDM) during pregnancy (6-8 weeks postpartum and 1-2 years postpartum).

GDM is the most common metabolic disorder in pregnant women encountered by endocrinologists and obstetrician-gynecologists. Despite advances in obstetric diabetology, the overall incidence of pregnancy complications and neonatal morbidity in GDM does not fall below 80%. The course of pregnancy in this pathology is complicated by the development of gestosis in 25-65% of cases, and its severe forms are observed in 2.9-3.7% of cases ¹ .

Due to the fact that in most pregnant women the disease occurs without severe hyperglycemia and obvious clinical symptoms, one of the features of GDM is the difficulty of its diagnosis and late detection.

Incidence of neonatal GDM:

• Erb’s palsy – 7.8%
• Severe asphyxia – 5.3%
• Fetal shoulder dystocia ~ 6.3%
• Fracture of the clavicle of a newborn – 19%
• Violation of cerebral circulation of traumatic genesis – 20%
• There is a high probability of developing hyperinsulinism and postnatal hypoglycemia, polycythemia and hyperbilirubinemia, neurological disorders GDM is a serious medical and social problem, because. significantly increases the frequency of undesirable pregnancy outcomes for the mother and for the fetus (newborn), is a risk factor for the development of obesity, type 2 diabetes and cardiovascular diseases in the mother and offspring in the future.