All About The Hemoglobin A1c Test
People with diabetes used to depend only on urine tests or daily finger sticks to measure their blood sugars. These tests are accurate, but only in the moment. As an overall measurement of blood sugar control, they’re very limited. This is because blood sugar can vary wildly depending on the time of day, activity levels, and even hormone changes. Some people may have high blood sugars at 3 a.m. and be totally unaware of it. Once A1C tests became available in the 1980s, they became an important tool in controlling diabetes. A1C tests measure average blood glucose over the past two to three months. So even if you have a high fasting blood sugar, your overall blood sugars may be normal, or vice versa. A normal fasting blood sugar may not eliminate the possibility of type 2 diabetes. This is why A1C tests are now being used for diagnosis and screening of prediabetes. Because it doesn’t require fasting, the test can be given as part of an overall blood screening. The A1C test is also known as the hemoglobin A1C test or HbA1C test. Other alternate names include the glycosylated hemoglobin test, glycohemoglobin test, and glycated hemoglobin test. A1C measures the amount of hemoglobin in the blood that has glucose attached to it. Hemoglobin is a protein found inside red blood cells that carries oxygen to the body. Hemoglobin cells are constantly dying and regenerating, but they have a lifespan of approximately three months. Glucose attaches, or glycates, to hemoglobin, so the record of how much glucose is attached to your hemoglobin also lasts for about three months. If there’s too much glucose attached to the hemoglobin cells, you’ll have a high A1C. If the amount of glucose is normal, your A1C will be normal. The test is effective because of the lifespan of the hemogl Continue reading >>
Why The A1c Test Is Important
The A1c is a blood test, done in a lab, that shows what your average blood sugar has been for the past 3 months. Other names for this test are glycosylated hemoglobin, glycohemoglobin, hemoglobin A1c, and HbA1c. How the A1c Test Works The glucose that the body doesn't store or use for energy stays in the blood and attaches to red blood cells, which live in the bloodstream for about 4 months. The lab test measures the amount of glucose attached to the red blood cells. The amount is the A1c and is shown as a percentage. Your A1c number can give you and your health care team a good idea of how well you've controlled your blood sugar over the previous 2 to 3 months. When you get your A1c result from a Kaiser Permanente lab, you'll also see another number called the estimated Average Glucose, or eAG. Understanding the eAG Your estimated Average Glucose (eAG) number is calculated from the result of your A1c test. Like the A1c, the eAG shows what your average blood sugars have been over the previous 2 to 3 months. Instead of a percentage, the eAG is in the same units (mg/dl) as your blood glucose meter. The chart shows the relationship between the A1c percentage and the eAG. If A1c % is: Your eAG is: 6 126 6.5 140 7 154 7.5 169 8 183 8.5 197 9 212 9.5 226 10 240 10.5 255 11 269 11.5 283 12 298 What the Numbers Mean The A1c and eAG reflect your average blood sugar over a period of time. These numbers help you and your doctor see how well your treatment plan is working. The higher your A1c and eAG numbers are, the higher your chances for having long-term health problems caused by consistently high blood sugar levels. These problems include heart attacks, strokes, kidney failure, vision problems, and numbness in your legs or feet. The lower your A1c and eAG numbers, the lower you Continue reading >>
What's A "normal" A1c? When Is It Misleading?
By Adithi Gandhi and Jeemin Kwon Why we use A1c, what values are recommended, and what impacts A1c – everything from anemia to vitamins Want more information just like this? Hemoglobin A1c (“HbA1c” or just “A1c”) is the standard for measuring blood sugar management in people with diabetes. A1c reflects average blood sugars over 2 to 3 months, and through studies like DCCT and UKPDS, higher A1c levels have been shown to be associated with the risk of certain diabetes complications (eye, kidney, and nerve disease). For every 1% decrease in A1c, there is significant pretection against those complications. However, as an average over a period of months, A1c cannot capture critical information such as time spent in a target range (70-180 mg/dl) and hypoglycemia (less than 70 mg/dl). This article describes why A1c is used in the first place, as well as factors that can lead to misleadingly high or low values. In a follow-up piece, we will discuss time-in-range, hypoglycemia, hyperglycemia, blood sugar variability, and how to measure and interpret them. Click to jump down to a section: What tools are available if an A1c test is not accurate or sufficient? What is A1c and why is it used? A1c estimates a person’s average blood sugar levels over a 2 to 3-month span. It is the best measure we have of how well blood glucose is controlled and an indicator of diabetes management. Though A1c doesn’t provide day-to-day information, keeping A1c low has been proven to lower the risk of “microvascular” complications like kidney disease (nephropathy), vision loss (retinopathy), and nerve damage (neuropathy). The relationship between A1c and “macrovascular” complications like heart disease is harder to show in clinical trials, but having high blood sugar is a major ris Continue reading >>
What Do My A1c Test Results Mean?
By: Mandy Jones, Contributor, living with diabetes If youve had a healthcare appointment lately, you may have heard your healthcare provider mention your A1C level. So, whats that mean, exactly? A1C gives an estimate of your average blood sugar for the past three months. While your meter gives you an in-the-moment picture, this test gives a long-term overview. Specifically, it works by measuring how much sugar is attached to your red blood cells.2 A1C can be measured using a drop of blood from your fingertip, or a blood draw. This test is one of the standard recommended ways to diagnose diabetes, and is usually tested every 3-6 months. Most insurance companies cover at least two tests per year if you get your test done through your healthcare provider; you can also buy an at-home test kit from your local drugstore.3 When looking at your lab results, look for Hemoglobin A1C or HbA1c (sometimes it is also called glycated hemoglobin).4 According to the American Diabetes Association (ADA) Standards of Care, an A1C greater than 6.4% indicates diabetes.1 An A1C between 5.7% and 6.4% indicates an increased risk of developing diabetes, or prediabetes as your healthcare provider may say.1 Having a high A1C could mean that youve had high blood sugars for the past three months. Having high blood sugars over an extended period of time deteriorates blood vessels and nerves. This damage to blood vessels and nervescan put you at risk for heart attacks and strokes, damage to organs like the kidneys, reduced energy, and slower healing from infections.2 The ADA says that for people with diabetes (who arent pregnant) who are managing blood sugars with oral medications or insulin, a reasonable goal is to have an A1C of less than 7%.1Some healthcare providers may suggest a higher or lower Continue reading >>
Print Overview The A1C test is a common blood test used to diagnose type 1 and type 2 diabetes and then to gauge how well you're managing your diabetes. The A1C test goes by many other names, including glycated hemoglobin, glycosylated hemoglobin, hemoglobin A1C and HbA1c. The A1C test result reflects your average blood sugar level for the past two to three months. Specifically, the A1C test measures what percentage of your hemoglobin — a protein in red blood cells that carries oxygen — is coated with sugar (glycated). The higher your A1C level, the poorer your blood sugar control and the higher your risk of diabetes complications. Why it's done An international committee of experts from the American Diabetes Association, the European Association for the Study of Diabetes and the International Diabetes Federation, recommend that the A1C test be the primary test used to diagnose prediabetes, type 1 diabetes and type 2 diabetes. After a diabetes diagnosis, the A1C test is used to monitor your diabetes treatment plan. Since the A1C test measures your average blood sugar level for the past two to three months instead of your blood sugar level at a specific point in time, it is a better reflection of how well your diabetes treatment plan is working overall. Your doctor will likely use the A1C test when you're first diagnosed with diabetes. This also helps establish a baseline A1C level. The test may then need to be repeated while you're learning to control your blood sugar. Later, how often you need the A1C test depends on the type of diabetes you have, your treatment plan and how well you're managing your blood sugar. For example, the A1C test may be recommended: Once every year if you have prediabetes, which indicates a high risk of developing diabetes Twice a year if Continue reading >>
What Does A1c Stand For?
You may have heard of a diabetes test called a hemoglobin A1c, sometimes called HgbA1c, HbA1c, or just A1C. What is an A1C test, and what should you know about it? HgbA1c is hemoglobin (pronounced HE-mo-glow-bin) that has sugar attached to it. Hemoglobin is the protein that carries oxygen from the lungs to all the cells of the body. Hemoglobin is an important component of red blood cells (RBCs). Nearly all cells in the human body need oxygen to power them. All animals with backbones, except one family of fish, have hemoglobin. Hemoglobin and molecules like it are also found in many invertebrates, plants, and fungi. Types of hemoglobin The “A” in Hemoglobin A (HgbA) stands for “adult.” After a person reaches six months of age, nearly all the hemoglobin is type A. About 98% of HgbA is type 1, or HgBA1. There is also HgBA2 (in addition to other types of hemoglobin), but not much. Type A1 has subtypes A1a, A1b, A1c, and others. Type A1c is the most common, making up about two-thirds of hemoglobin with glucose attached. HgbA1c is a good marker for glucose control, because the more glucose is circulating in the blood, the more hemoglobin will be glycated (covered with sugar). What an A1C test means Once hemoglobin is glycated, it stays that way until the red blood cell dies. Red blood cells live an average of three to four months. That is why your A1C level indicates your average glucose over the last few months. A1C results are expressed as the percentage of all hemoglobin that is glycated. An A1C of 7.0% means an average blood glucose level of 154 mg/dl, according to the American Diabetes Association (ADA). You can use this calculator to convert your A1C to an estimated average blood glucose number. However, A1C tests can sometimes mislead because: • Newer blood c Continue reading >>
Your A1c Results: What Do They Mean?
If you have diabetes, you should have an A1C test at least twice each year to find out your long-term blood glucose control. The A1C test measures your average blood glucose during the previous 2-3 months, but especially during the previous month. For people without diabetes, the normal A1C range is 4-6%. For people with diabetes, the lower the A1C value, the better the diabetes control and the lower the risk of developing complications such as eye, heart, and kidney disease. Your goal should be to have A1C values less than 7%. That may be a hard target to hit, but it is important to try because the lower your A1C, the lower your health risk. The table on this page shows what your A1C results say about your blood glucose control during the past few months. Some people are surprised when they have a high A1C result because when they check their blood glucose with their meter, they have relatively low numbers. But remember that checking your blood glucose gives you only a momentary sample of your blood glucose control. The A1C test measures your blood glucose control at all times during the previous 2-3 months, even times such as after meals or when you are asleep, when you don't usually check your blood glucose. Think of the A1C test as feedback to help you better control your diabetes and improve your diabetes care habits. By giving you important information about your long-term control, the A1C test can help you stay motivated to do your best on diabetes self care. Talk with your doctor and other members of the health care team about your A1C results and how you can use them to better manage diabetes. Within the next few months, the federal government will implement the first major reorganization of the Medicare system for many years: the Medicare Prescription Drug Imp Continue reading >>
5 Ways To Lower Your A1c
For some, home blood sugar testing can be an important and useful tool for managing your blood sugar on a day-to-day basis. Still, it only provides a snapshot of what’s happening in the moment, not long-term information, says Gregory Dodell, MD, assistant clinical professor of medicine, endocrinology, diabetes, and bone disease at Mount Sinai Health System in New York City. For this reason, your doctor may occasionally administer a blood test that measures your average blood sugar level over the past two to three months. Called the A1C test, or the hemoglobin A1C test, this provides a more accurate picture of how well your type 2 diabetes management plan is working. Taking the A1C Test If your diabetes is well controlled and your blood sugar levels have remained stable, the American Diabetes Association recommends that you have the A1C test two times each year. This simple blood draw can be done in your doctor's office. Some doctors can use a point-of-care A1C test, where a finger stick can be done in the office, with results available in about 10 minutes. The A1C test results provide insight into how your treatment plan is working, and how it might be modified to better control the condition. Your doctor may want to run the test as often as every three months if your A1C is not within your target range. What the A1C Results Mean The A1C test measures the glucose (blood sugar) in your blood by assessing the amount of what’s called glycated hemoglobin. “Hemoglobin is a protein within red blood cells. As glucose enters the bloodstream, it binds to hemoglobin, or glycates. The more glucose that enters the bloodstream, the higher the amount of glycated hemoglobin,” Dr. Dodell says. An A1C level below 5.7 percent is considered normal. An A1C between 5.7 and 6.4 perce Continue reading >>
Hemoglobin A1c Test (hba1c)
Hemoglobin A1c, often abbreviated HbA1c, is a form of hemoglobin (a blood pigment that carries oxygen) that is bound to glucose. The blood test for HbA1c level is routinely performed in people with type 1 and type 2 diabetes mellitus. Blood HbA1c levels are reflective of how well diabetes is controlled. The normal range for level for hemoglobin A1c is less than 6%. HbA1c also is known as glycosylated, or glycated hemoglobin. HbA1c levels are reflective of blood glucose levels over the past six to eight weeks and do not reflect daily ups and downs of blood glucose. High HbA1c levels indicate poorer control of diabetes than levels in the normal range. HbA1c is typically measured to determine how well a type 1 or type 2 diabetes treatment plan (including medications, exercise, or dietary changes) is working. How Is Hemoglobin A1c Measured? The test for hemoglobin A1c depends on the chemical (electrical) charge on the molecule of HbA1c, which differs from the charges on the other components of hemoglobin. The molecule of HbA1c also differs in size from the other components. HbA1c may be separated by charge and size from the other hemoglobin A components in blood by a procedure called high pressure (or performance) liquid chromatography (HPLC). HPLC separates mixtures (for example, blood) into its various components by adding the mixtures to special liquids and passing them under pressure through columns filled with a material that separates the mixture into its different component molecules. HbA1c testing is done on a blood sample. Because HbA1c is not affected by short-term fluctuations in blood glucose concentrations, for example, due to meals, blood can be drawn for HbA1c testing without regard to when food was eaten. Fasting for the blood test is not necessary. What Are Continue reading >>
The A1c Test & Diabetes
What is the A1C test? The A1C test is a blood test that provides information about a person’s average levels of blood glucose, also called blood sugar, over the past 3 months. The A1C test is sometimes called the hemoglobin A1c, HbA1c, or glycohemoglobin test. The A1C test is the primary test used for diabetes management and diabetes research. How does the A1C test work? The A1C test is based on the attachment of glucose to hemoglobin, the protein in red blood cells that carries oxygen. In the body, red blood cells are constantly forming and dying, but typically they live for about 3 months. Thus, the A1C test reflects the average of a person’s blood glucose levels over the past 3 months. The A1C test result is reported as a percentage. The higher the percentage, the higher a person’s blood glucose levels have been. A normal A1C level is below 5.7 percent. Can the A1C test be used to diagnose type 2 diabetes and prediabetes? Yes. In 2009, an international expert committee recommended the A1C test as one of the tests available to help diagnose type 2 diabetes and prediabetes.1 Previously, only the traditional blood glucose tests were used to diagnose diabetes and prediabetes. Because the A1C test does not require fasting and blood can be drawn for the test at any time of day, experts are hoping its convenience will allow more people to get tested—thus, decreasing the number of people with undiagnosed diabetes. However, some medical organizations continue to recommend using blood glucose tests for diagnosis. Why should a person be tested for diabetes? Testing is especially important because early in the disease diabetes has no symptoms. Although no test is perfect, the A1C and blood glucose tests are the best tools available to diagnose diabetes—a serious and li Continue reading >>
What Is The A1c Test? How Does A1c Relate To Blood Glucose?
Anyone with diabetes will be familiar with finger-prick testing for monitoring blood glucose to see how well they are managing their disease. This kind of regular testing is essential for most people with diabetes, but what role does an occasional hemoglobin A1C blood test play in controlling blood sugars, and how does it work? Contents of this article: What is the A1C test? The abbreviation A1C is used in the US (sometimes with a lower-case 'c' - A1c) and is short for glycated hemoglobin (sometimes called 'glycosylated' hemoglobin or glycohemoglobin). The other abbreviations in use are: HbA1c (widely used internationally) HbA1c Hb1c HgbA1C. The A1C test is a blood test used to measure the average level of glucose in the blood over the last two to three months. This test is used to check how well blood sugar levels are being controlled in a person with diabetes and can also be used in the diagnosis of diabetes.1 Hemoglobin is the protein in red blood cells which is responsible for transporting oxygen around the body. When blood glucose levels are elevated, some of the glucose binds to hemoglobin and, as red blood cells typically have a lifespan of 120 days, A1C (glycated hemoglobin) is a useful test because it offers an indication of longer term blood glucose levels.2 The particular type of hemoglobin that glucose attaches to is hemoglobin A, and the combined result is call glycated hemoglobin. As blood glucose levels rise, more glycated hemoglobin forms, and it persists for the lifespan of red blood cells, about four months.2 Therefore, the A1C level directly correlates to the average blood glucose level over the previous 8-12 weeks; A1C is a reliable test that has been refined and standardized using clinical trial data.3 There are two key things to know about the appl Continue reading >>
- Home blood glucose test: How to test for diabetes at home
- Diabetes and the A1C Test: What Does It Tell You?
- Postprandial Blood Glucose Is a Stronger Predictor of Cardiovascular Events Than Fasting Blood Glucose in Type 2 Diabetes Mellitus, Particularly in Women: Lessons from the San Luigi Gonzaga Diabetes Study
The A1c Test: Uses, Procedure, Results
The A1C test, also known as an HbA1C, hemoglobin A1c,glycated hemoglobin, or glycosylated hemoglobin test, is a blood test that shows your average blood sugar levels for the past two to three months. It's a broader test than conventional home glucose monitoring , which measures your blood sugar at any given moment. It's used to diagnose and monitor diabetes. Hemoglobin A, a protein found inside red blood cells, carries oxygen throughout your body. When there's glucose in your bloodstream, it can stick (glycate) to hemoglobin A. The more glucose that's in your blood, the more it does this, creating a higher percentage of glycated hemoglobin proteins. Once glucose sticks to a hemoglobin protein , it typically remains there for the lifespan of the hemoglobin A protein (as long as 120 days). This means that, at any moment, the glucose attached to the hemoglobin A protein reflects the level of your blood sugar over the last two to three months. The A1C test measures how much glucose is actually stuck to hemoglobin A, or more specifically, what percent of hemoglobin proteins are glycated. Hemoglobin with glucose attached to it is called A1C. Thus, having a 7percentA1C means that 7 percent of your hemoglobin proteins are glycated. Your doctor may order an A1C test for these reasons: If you're overweight or obese and you have one or more other risk factors for developing type 2 diabetes , your doctor will likely order an A1C test as part of your normal medical exam every year. Such risk factors include: High-risk ethnicity (Native American, African American, Latino, Asian American) The majority of people who end up with type 2 diabetes have prediabetes first, which means that your blood sugar is higher than normal, but not high enough to be diagnosed with diabetes. The A1C tes Continue reading >>
On This Site Tests: Glucose Tests; Urine Albumin; Urine Albumin/Creatinine Ratio; Fructosamine Conditions: Diabetes In the News: Screening, Diet and Exercise Key Factors in Task Force's New Diabetes Guidelines (2015), Task Force Updates Recommendations for Screening for Pre-Diabetes and Diabetes in Adults (2014), New Report Finds that Diabetes is on the Rise (2014) Elsewhere On The Web American Diabetes Association: Diabetes Basics American Diabetes Association: Risk Test American Association of Diabetes Educators Centers for Disease Control and Prevention: Diabetes Public Health Resource National Diabetes Information Clearinghouse: Prevent diabetes problems - Keep your diabetes under control National Institute of Diabetes and Digestive and Kidney Diseases: Diabetes A to Z National Glycohemoglobin Standardization Program American Diabetes Association – DiabetesPro, estimated Average Glucose, eAG Ask a Laboratory Scientist Your questions will be answered by a laboratory scientist as part of a voluntary service provided by one of our partners, the American Society for Clinical Laboratory Science (ASCLS). Click on the Contact a Scientist button below to be re-directed to the ASCLS site to complete a request form. If your question relates to this web site and not to a specific lab test, please submit it via our Contact Us page instead. Thank you. Continue reading >>
Hemoglobin A1c Test (hba1c, A1c, Hb1c)
Hemoglobin A1c definition and facts Hemoglobin A1c is a protein on the surface of red blood cells that sugar molecules stick to, usually for the life of the red blood cell (about three months). The higher the level of glucose in the blood, the higher the level of hemoglobin A1c is detectable on red blood cells. Hemoglobin A1c levels correlate with average levels of glucose in the blood over an approximately three-month time period. Normal ranges for hemoglobin A1c in people without diabetes is about 4% to 5.9%. People with diabetes with poor glucose control have hemoglobin A1c levels above 7%. Hemoglobin A1c levels are routinely used to determine blood sugar control over time in people with diabetes. Decreasing hemoglobin A1c levels by 1% may decrease the risk of microvascular complications (for example, diabetic eye, nerve, or kidney disease) by 10%. Hemoglobin A1c levels should be checked, according to the American Diabetic Association, every six months in individuals with stable blood sugar control, and every three months if the person is trying to establish stable blood sugar control. Hemoglobin A1c has many other names such as glycohemoglobin, glycated hemoglobin, glycosylated hemoglobin, and HbA1c. To explain what hemoglobin A1c is, think in simple terms. Sugar sticks to things, and when it has been stuck to something for a long time it's harder to the get sugar (glucose) off. In the body, sugar sticks too, particularly to proteins. The red blood cells that circulate in the body live for about three months before they die. When sugar (glucose) sticks to these red blood cells by binding to hemoglobin A1c, it gives us an idea of how much glucose has been around in the blood for the preceding three months. Hemoglobin A1c is a minor component of hemoglobin to which gl Continue reading >>
Average blood glucose and the A1C test Your A1C test result (also known as HbA1c or glycated hemoglobin) can be a good general gauge of your diabetes control, because it provides an average blood glucose level over the past few months. Unlike daily blood glucose test results, which are reported as mg/dL, A1C is reported as a percentage. This can make it difficult to understand the relationship between the two. For example, if you check blood glucose 100 times in a month, and your average result is 190 mg/dL this would lead to an A1C of approximately 8.2%, which is above the target of 7% or lower recommended by the American Diabetes Association (ADA) for many adults who are not pregnant. For some people, a tighter goal of 6.5% may be appropriate, and for others, a less stringent goal such as 8% may be better.1 Talk to your doctor about the right goal for you. GET YOURS FREE The calculation below is provided to illustrate the relationship between A1C and average blood glucose levels. This calculation is not meant to replace an actual lab A1C result, but to help you better understand the relationship between your test results and your A1C. Use this information to become more familiar with the relationship between average blood glucose levels and A1C—never as a basis for changing your disease management. See how average daily blood sugar may correlate to A1C levels.2 Enter your average blood sugar reading and click Calculate. *Please discuss this additional information with your healthcare provider to gain a better understanding of your overall diabetes management plan. The calculation should not be used to make therapy decisions or changes. What is A1C? Performed by your doctor during your regular visits, your A1C test measures your average blood sugar levels by taking a Continue reading >>