All About Your A1C

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What has your blood sugar been up to lately? Get an A1C test to find out your average levels—important to know if you’re at risk for prediabetes or type 2 diabetes, or if you’re managing diabetes.

The A1C test—also known as the hemoglobin A1C or HbA1c test—is a simple blood test that measures your average blood sugar levels over the past 3 months. It’s one of the commonly used tests to diagnose prediabetes and diabetes, and is also the main test to help you and your health care team manage your diabetes. Higher A1C levels are linked to diabetes complications, so reaching and maintaining your individual A1C goal is really important if you have diabetes.

What Does the A1C Test Measure?

When sugar enters your bloodstream, it attaches to hemoglobin, a protein in your red blood cells. Everybody has some sugar attached to their hemoglobin, but people with higher blood sugar levels have more. The A1C test measures the percentage of your red blood cells that have sugar-coated hemoglobin.

Who Should Get an A1C Test, and When?

Testing for diabetes or prediabetes:
Get a baseline A1C test if you’re an adult over age 45—or if you’re under 45, are overweight, and have one or more risk factors for prediabetes or type 2 diabetes:

• If your result is normal but you’re over 45, have risk factors, or have ever had gestational diabetes, repeat the A1C test every 3 years.
• If your result shows you have prediabetes, talk to your doctor about taking steps now to improve your health and lower your risk for type 2 diabetes. Repeat the A1C test as often as your doctor recommends, usually every 1 to 2 years.
• If you don’t have symptoms but your result shows you have prediabetes or diabetes, get a second test on a different day to confirm the result.
• If your test shows you have diabetes, ask your doctor to refer you to diabetes self-management education and support services so you can have the best start in managing your diabetes.

Managing diabetes:
If you have diabetes, get an A1C test at least twice a year, more often if your medicine changes or if you have other health conditions. Talk to your doctor about how often is right for you.

How to Prepare for Your A1C Test

The test is done in a doctor’s office or a lab using a sample of blood from a finger stick or from your arm. You don’t need to do anything special to prepare for your A1C test. However, ask your doctor if other tests will be done at the same time and if you need to prepare for them.

Your A1C Result

Diagnosing Prediabetes or Diabetes

A normal A1C level is below 5.7%, a level of 5. 7% to 6.4% indicates prediabetes, and a level of 6.5% or more indicates diabetes. Within the 5.7% to 6.4% prediabetes range, the higher your A1C, the greater your risk is for developing type 2 diabetes.

Managing Diabetes
Your A1C result can also be reported as estimated average glucose (eAG), the same numbers (mg/dL) you’re used to seeing on your blood sugar meter:

What Can Affect Your A1C Result?

Get your A1C tested in addition to—not instead of—regular blood sugar self-testing if you have diabetes.

Several factors can falsely increase or decrease your A1C result, including:

• Kidney failure, liver disease, or severe anemia.
• A less common type of hemoglobin that people of African, Mediterranean, or Southeast Asian descent and people with certain blood disorders (such as sickle cell anemia or thalassemia) may have.
• Certain medicines, including opioids and some HIV medications.
• Blood loss or blood transfusions.
• Early or late pregnancy.

Let your doctor know if any of these factors apply to you, and ask if you need additional tests to find out.

Your A1C Goal

The goal for most people with diabetes is 7% or less. However, your personal goal will depend on many things such as your age and any other medical conditions. Work with your doctor to set your own individual A1C goal.

Younger people have more years with diabetes ahead, so their goal may be lower to reduce the risk of complications, unless they often have hypoglycemia (low blood sugar, or a “low”). People who are older, have severe lows, or have other serious health problems may have a higher goal.

A1C: Just Part of the Toolkit

A1C is an important tool for managing diabetes, but it doesn’t replace regular blood sugar testing at home. Blood sugar goes up and down throughout the day and night, which isn’t captured by your A1C. Two people can have the same A1C, one with steady blood sugar levels and the other with high and low swings.

If you’re reaching your A1C goal but having symptoms of highs or lows, check your blood sugar more often and at different times of day. Keep track and share the results with your doctor so you can make changes to your treatment plan if needed.

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A1C Test and A1C Calculator

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.

A1C calculator*

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 sample of hemoglobin A1C cells—a component of your red blood cells.

Here’s how it works:

• Some blood sugar (or glucose) naturally attaches itself to A1C cells as they move through your bloodstream. When this happens, the cell is considered “glycated.”
• Once a cell has been glycated, it stays that way. And since each A1C cell has a lifespan of about 4 months, your A1C sample will include cells that are a few days, a few weeks and a few months old. As a result, the test covers a span of about 2 to 3 months.
• The more sugar in your blood, the higher the percentage of glycated A1C cells you’ll have—that percentage is your A1C test result.³

Self-monitoring blood glucose and A1C

A1C is important, but it’s not a substitute for frequent self-monitoring. Only regular blood sugar checks show you how meals, activity, medications and stress affect your blood sugar at a single moment in time, as well as over the course of a day or week.

Without regular self-testing to provide day-to-day insights, an A1C result can be confusing. Because it gives a long-term view, a person with frequent highs and lows could have an in-range A1C result that looks quite healthy.⁴

The only way to get a complete picture of your blood sugar control is by reviewing your day-to-day self-checks along with your regular A1C tests, and working closely with your healthcare team to interpret the results.

How often do I need an A1C test?

This calculator only estimates how the A1C of someone who self-monitors quite frequently might correlate with their average meter readings. But many factors can affect blood glucose, so it’s critical to have your A1C checked by your doctor regularly.

The ADA recommends an A1C test at least 2 times a year for those who are in good control. For those who have changed their therapy or who are not in good control and not meeting glycemic goals, an A1C test is recommended quarterly. Your doctor will help you decide what’s right for you.¹

Benefits of lowering your A1C test result

Keeping your A1C test results low can significantly reduce the risk of long-term diabetes complications such as nerve problems, damage to your eyes, kidney disease and heart problems.³

¹American Diabetes Association. Standards of medical care in diabetes—2017 [position statement]. Diabetes Care. 2017;40(1): S1-S135. Available at: http://care.diabetesjournals.org/content/diacare/suppl/2016/12/15/40.Sup…. Accessed July 28, 2017.

²Nathan DM, Kuenen J, Borg R, Zheng H, Schoenfeld D, Heine RJ. Translating the A1C assay into estimated average glucose values. Diabetes Care. 2008;31(8): 1473-1478. Available at http://care.diabetesjournals.org/content/31/8/1473.full.pdf. Accessed July 28, 2017.

³American Diabetes Association. A1C and eAG. Available at: http://www.diabetes.org/living-with-diabetes/treatment-and-care/blood-gl…. Accessed July 28, 2017.

⁴Tylee TS, Trence DL. Glycemic variability: looking beyond the A1C. Diabetes Spectrum. 2012;24(3): 149-153. Available at http://spectrum.diabetesjournals.org/content/25/3/149.full. Accessed July 28, 2017.

Glycosylated hemoglobin – what is it, the norm in women and men

It is very important in the management of patients with diabetes 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 taking, 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 the patient’s carbohydrate metabolism over a long period of time only by measuring the concentration of glycated hemoglobin in the blood, according to the recommendations of the Committee for the Control of Diabetes and its Clinical Complications (DCCT).

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

Characteristics of indicator

Glycosylated hemoglobin (the term “glycated hemoglobin” is also used) is formed as a result of the non-enzymatic addition of glucose to the N-terminal regions of the β-chains of hemoglobin A1 _{globin and is designated as HbA1c. The concentration of HbA1c is directly proportional to the average concentration of glucose in the blood. In healthy people, the concentration of HbA1c in the blood is from 4.80 to 5.90%, in patients with diabetes its level is 2-3 times higher (depending on the degree of hyperglycemia).}

The resulting HbA1 accumulates inside the erythrocytes and persists throughout the life of the erythrocyte. The half-life of erythrocyte circulation in the bloodstream is 60 days, thus, the HbA1c concentration reflects the patient’s glycemia level 60-90 days before the study [2, 3].

A huge number of studies using traditional methods for measuring glucose content have confirmed the relationship between HbA1c and the level of glycemia of the patient [12-14]. Results of studies conducted by DCCT in 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 glycated hemoglobin. As a result of his work, the National Glycosylated Hemoglobin Standardization Program (NGSP) was developed. Manufacturers of test systems for measuring glycated hemoglobin have been required to undergo rigorous testing to ensure that the results correspond to data obtained by reference DCCT methods. In case of a positive result of the check, 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;
• column techniques;
• immunological techniques.

When a laboratory chooses an analyzer for glycated hemoglobin testing, 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 DCCT. Such a comparison maximizes the reliability of the research results.

It is extremely important that the attending physician use in his work the results of studies obtained only in those laboratories that conduct the study of glycosylated hemoglobin using NGSP certified methods.

Study of HbA1c concentration in the laboratories of the Citylab Association

The concentration of glycosylated hemoglobin (HbA1c) in the laboratories of the Citylab Association is determined by the reference method (DCCT) of 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 analyzers. hemoglobin. This study is 23-10-002 – Glycosylated hemoglobin.

Mean blood glucose assessment

The DCCT study group demonstrated the clinical relevance of HbA1c as an estimate of mean blood glucose concentration (over 60-90 days). In these studies, patients had their daily glucose profile recorded every 3 months (seven measurements daily). The resulting profile was compared with the level of HbA1c. Over 36,000 studies have been conducted over 9 years. Empirically, a linear relationship between the average glucose content and the HbA1c level was obtained:

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

HbA1c is the 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 in the study of glucose concentration in capillary blood. The concentration of glucose in the blood serum 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 brackets 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 type 2 diabetes when taking insulin or oral hypoglycemic drugs.

To convert glucose concentration in mg/100 ml to SI units (mmol/l), the following formula is used:

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

Recommended testing frequency

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

According to the American Diabetes Association, women with diabetes in the pre-pregnancy period need a special monitoring regimen. It is recommended to reduce the level of HbA1c in order to create optimal conditions in the body of the future mother for conception and fetal development. At the beginning, HbA1c should be tested monthly. When carbohydrate metabolism is stabilized with appropriate therapy, HbA1c testing should be performed at intervals of 6-8 weeks prior to conception [5, 6].

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

Interpretation of test results

The goal of hypoglycemic therapy in diabetes mellitus is to normalize blood glucose levels. DCCT studies 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%, and the risk of polyneuropathy decreases by 60% [10].

Below are the therapeutic goals in the treatment of diabetes mellitus according to the Target Federal 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: In parentheses are glucose values ​​in mg/100 ml.

The federal target program “Diabetes mellitus” [1] adopted the values ​​recommended by the European Committee for Diabetes Recommendations [18, 19].

When evaluating the results of treatment in patients with concomitant diseases, young people, the elderly, pregnant women and patients with an unusual pattern of diabetes mellitus, other criteria for stabilizing carbohydrate metabolism should be used.

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

• enhanced patient education on self-monitoring of glucose levels;
• organization of patient support groups;
• regular examination by an endocrinologist;
• changes in drug therapy;
• more frequent testing of glucose and HbA1c.

Conclusions

1. The HbA1c study allows to assess the level of glycemia in a patient with diabetes mellitus for 60-90 days prior to the study.
2. This study provides an opportunity to monitor the course of the disease and control the adequacy of the treatment.
3. An HbA1c test should be performed to assess the risk of complications in a diabetic patient.

References

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. Diagnosis and treatment. // Practice, 2008.
3. Popova Yu.S. Diabetes. // Krylov, 2008.
4. AD. Implications of the United Kingdom Prospective Diabetes Study (Position Statement). // Diabetes Care 1999, (SI), 27-31.
5. AD. Standards of Medical Care for Patients With Diabetes Mellitus (Position Statement). // Diabetes Care 1999, (SI), 32-41.
6. AD. Preconception Care of Women With Diabetes (Position Statement). // Diabetes Care 1999, (SI), 62-63.
7. AD. 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, what is this analysis and who needs to study it? – Family Clinic

Glycated or glycosylated hemoglobin is also called HbA1c, hemoglobin a1c. What does it mean?

A stable connection of hemoglobin with glucose is formed as a result of a special biochemical reaction – non-enzymatic glycosylation. Glycated hemoglobin is divided into fractions, 80% of which is HbA1c. The lifespan of an erythrocyte is 30 days, so HbA1c is an integral indicator that reflects fluctuations in glucose levels over this period of time.

In a healthy person, the metabolism in the body is not disturbed, the glucose level is normal and the HbA1c indicator does not exceed 6.0%.

Diagnosis using the HbA1c study is necessary to detect diabetes mellitus or assess the risk of the disease.

It is very important to diagnose the presence of carbohydrate metabolism disorders at an early stage, when therapeutic measures are most effective and the risk of developing complications of diabetes mellitus is significantly reduced.

Since there are no symptoms characteristic of diabetes mellitus at an early stage of the disease, a correct diagnosis can only be made with the help of a laboratory examination.

In 2011, WHO (World Health Organization) approved the possibility of using HbA1c to diagnose diabetes.

The level of HbA1c ≥6.5% was chosen as a diagnostic criterion for DM. The level of HbA1c 6.0-6.4% by itself does not allow making any diagnoses, but does not exclude the possibility of diagnosing diabetes mellitus by the level of blood glucose.

Risk factors for type 2 diabetes:

• Age ≥ 45 years.

• Overweight and obesity (BMI ≥ 25 kg/m2).

• Family history of diabetes (parents or siblings with type 2 diabetes).

• Habitually low physical activity.

• Impaired fasting glycemia or impaired glucose tolerance in previous years.

• Women with diabetes are pregnant or have a large fetus (≥ 4.1 kg).

• Arterial hypertension (≥ 140/90 mm Hg or drug antihypertensive therapy).

• HDL cholesterol ≤ 0.9mmol/l and/or triglycerides ≥ 2.82 mmol/l.

• Polycystic ovary syndrome.

• The presence of cardiovascular disease.

In the presence of these risk factors for the development of diabetes, it is recommended to control the level of HbA1c once a year.

Identification of risk groups is possible using simple questionnaires:

Do you have prediabetes or type 2 diabetes? Questionnaire for patients

Instruction

• Answer all 8 questions of the questionnaire.

• For each question, choose 1 correct answer and mark it in the appropriate box.

• Add up all the points corresponding to your answers to the questions.

• Use your total score to determine your risk of developing diabetes or prediabetes.

• Give the completed questionnaire to your doctor/nurse and ask them to explain the results of the questionnaire to you.

1. Age

¨ Up to 45 years – 0 points

¨ 45 – 54 years – 2 points

¨ 55 – 64 years – 3 points

¨ Over 65 years old – 4 points

2. Body mass index

The Body Mass Index measures whether you are overweight or obese. You can calculate your body mass index yourself:

Weight_____kg: (height_____m)2 = _____kg/m2

¨ Less than 25 kg/m2 – 0 points

¨ 25 – 30 kg/m2 – 1 point

¨ More than 30 kg/m2 – 3 points

3. Waist circumference

Waist circumference also indicates whether you are overweight or obese.

Men Women

< 94 cm < 80 cm - 0 points

94 – 102 cm 80 – 88 cm – 3 points

> 102 cm > 88 cm – 4 points

4. How often do you eat vegetables, fruits or berries?

¨ Every day – 0 points

¨ Not every day – 1 point

5. Do you exercise regularly?

Do you exercise for 30 minutes every day or 3 hours a week?

¨ Yes – 0 points

¨ No – 2 points

6. Have you ever taken medication to lower your blood pressure regularly?

¨ No – 0 points

¨ Yes – 2 points

7. Have you ever had a higher than normal blood glucose (sugar) level (during medical examination, professional examination, during illness or pregnancy)?

¨ No – 0 points

¨ Yes – 5 points

8. Did any of your relatives have type 1 or type 2 diabetes?

¨ No – 0 points

¨ Yes: grandparents, aunts/uncles, cousins ​​- 3 points

¨ Yes: parents, sibling or own child 5 points

RESULTS:

Sum of points.

Your risk of developing diabetes within 10 years is:

• If you scored less than 12 points: You are in good health and should continue to lead a healthy lifestyle.

• If you scored 12 – 14 points: you may have prediabetes. You should consult with your doctor about how you should change your lifestyle.

• If you scored 15-20 points: you may have prediabetes or type 2 diabetes. You might want to check your blood glucose (sugar) levels. You must change your lifestyle. You may also need medication to lower your blood glucose (sugar) levels.

• If you scored more than 20 points: In all likelihood, you have type 2 diabetes. You should check the level of glucose (sugar) in the blood and try to normalize it. You will need to change your lifestyle and will need medication to control your blood glucose (sugar) levels.

Reduced risk of prediabetes or type 2 diabetes

You cannot change your age or genetic predisposition to prediabetes and diabetes, but you can change your lifestyle to reduce your risk of developing these conditions.

You can lose weight, become more physically active, and eat healthier foods.