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Is Fasting Required For A1c Test

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What Are We Looking For With Routine Blood Work

What is the difference between A1c and Fasting Blood Glucose Testing?

With most routine blood work, were trying to catch early warning signs of diseasebefore symptoms arise. The tests your practitioner orders will depend on your age and sex, along with your medical history and family risk factors. Baseline tests check for blood sugar levels, blood cell counts, and metabolic function . Your doctor will generally order panels that test for several things with one draw. Here are some of the most common blood tests we see in primary care:

  • A Complete Blood Count checks red blood cells, white blood cells, and platelets. A CBC can identify conditions including anemia, heart disease, autoimmune disease, leukemia, and other cancers.
  • A Basic Metabolic Panel checks kidney function, lung function, and blood sugar levels by testing blood filtration, blood sugar, and electrolyte levels. This test can identify common kidney problems, lung problems, and diabetes or pre-diabetes.
  • A Complete Metabolic Panel covers the tests included in a BMP with additional tests related to liver function.
  • A Lipid Panel checks for cholesterol and triglycerides in the blood and can detect the buildup of plaque in your arteries. This test is an important early screening for coronary artery disease.

Some other frequently ordered tests include:

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What Is The Benefit Of Hba1c Over Other Diabetes Tests

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

This is compared with other tests that can be used in the diagnosis of diabetes. A fasting blood sugar level, as the name implies, requires you to fast for a certain period of time before having the blood test.

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

How To Choose A Kit

Several FDA-approved home A1C test kits are available at pharmacies and online retailers. Some health insurance plans cover the cost, which can run between $50 to $150.

Accessories for the test, such as replacement strips, are sold as well, so be sure to check that you have all of the necessary parts. A very inexpensive box might contain only a few replacement accessories.

Buy your device from a reputable brand, and make sure the packaging is sealed before first use.

Currently approved brands include:

  • Testing instructions from the manufacturer

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A1c Results And What The Numbers Mean

*Any test used to diagnose diabetes requires confirmation with a second measurement, unless there are clear symptoms of diabetes.

Diabetes 6.5 percent or above

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

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

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

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

Glycosylated Hemoglobin Or Hemoglobin A1c

Hemoglobin A1c Blood Sugar Table

Reflects average blood sugar levels over the preceding 90-day period. Elevated levels are associated with prediabetes and diabetes. Individuals with diabetes have an increased risk of a cardiac event. A diabetic person’s risk for heart attack is the same as a non-diabetic person, who has experienced one heart attack, having a second heart attack. Aggressive global preventive risk reduction efforts, such as lower LDL targets, diet, exercise and blood pressure control, are recommended.

Goal values :

  • A range of 5.7-6.4 percent indicates an increased risk for development of diabetes , and lifestyle interventions may be beneficial.
  • A value equal or greater than 6.5 percent is considered diabetic.


This test may be measured any time of the day without fasting.

Glycosylated hemoglobin is blood glucose attached to hemoglobin . This test is often called the “diabetic report card.” It reflects the average blood sugar for the two to three month period before the test.

To calculate the average blood glucose level from the HbA1C:

HbA1C level x 33.3 86 = average blood glucose level for the past 90 days. HbA1C can be helpful to track diabetic control over time.

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Hba1c Not Fasting Morning Blood Sugar

Doctors used to use your fasting morning blood sugar level as a guide to managing diabetes. Now they depend far more on a test called Hemoglobin A1C, or HBA1C. Eating raises blood sugar levels. If your blood sugar rises too high, sugar sticks to the surface of cells where it cannot be removed. The sugar is converted to a poison called sorbitol that damages the cell to cause heart attacks, kidney damage, blindness and other nerve damage. Your fasting morning blood sugar level doesn’t tell you if you are getting cell damage, but the Hemoglobin A1C test actually measures how much sugar sticks to cells. Once you start treatment, your doctor should check you once a month to measure your HBA1C. If it is high, you should change your diet and or your doctor should change your medication. When the HBA1C is normal, you are doing everything right. See my reports on Who is Pre-Diabetic? Treatment of Insulin Resistance Dietary Treatment of Diabetes HWM Breuer. The postprandial blood glucose level – A new target for optimizing treatment of diabetes mellitus. European Heart Journal Supplements, 2000, Vol 2, Iss D, pp D36-D38. Checked 12/2/15Continue reading > >

A Need To Update Older Guidelines

Aldasouqi also points out that specialists currently recognize that eating before undergoing a blood cholesterol test is unlikely to affect relevant measurements. Therefore, having a meal before going in for a test may actually be better than fasting and potentially losing consciousness on the way to the laboratory.

He adds that the idea of fasting before a blood test comes from antiquated sets of guidelines from the 1970s, which specialists in Canada and most European countries no longer use.

For this reason, he says that United States-based specialists may want to consider revising their own guidelines to better fit the needs of their patients.

According to the studys findings, only 35 percent of participants had received advice about how to prevent a FEEHD event before going in for a blood cholesterol test.

We encourage patients who receive orders for a lab test, explains Aldasouqi, to ask their doctor if fasting is really necessary, and if so, how they should handle their diabetes medications during the fasting period to account for the changes in their blood sugar levels.

FEEHD is overlooked in clinical practice, and we aim to bring this problem to light and further educate doctors and patients about the consequences of fasting while on diabetes medications, he adds.

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A1c Captures Chronic Hyperglycemia Better Than Two Assessments Of Fasting Or 2

Diabetes has been diagnosed for decades with fasting plasma glucose assessment or, much less frequently, with an oral glucose tolerance test . Hyperglycemia as the biochemical hallmark of diabetes is unquestionable. However, fasting and 2-h OGTT gauge just a moment of a single day. In addition, the two assessments required to confirm diagnosis might be fallacious in describing a chronic and complex clinical condition. In this respect, there is no doubt that a biochemical or clinical parameter describing the extent of a biological phenomenon over a long period provides a more robust indicator of glycemia than a parameter describing it in the short term or in a given moment only. Accordingly, there are some good examples in medicine: urinary albumin excretion rate provides more reliable information on the presence and the degree of microalbuminuria than spot urinary albumin-to-creatinine ratio serum IGF-I is definitely more efficacious than serum growth hormone when monitoring patients with acromegaly, etc.

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For Monitoring Diabetes Control

What Is a Good Score on the A1c Diabetes Test?

Experts disagree somewhat on what the A1C target should be. The ADA recommends a general A1C target of less than 7% without significant hypoglycemia , while the American Association of Clinical Endocrinologists recommends a general target level of 6.5% or below.

The ADA’s Standards of Medical Care in Diabetes for 2021 note the following A1C targets:

A1C Targets for Diabetes Management
Most non-pregnant adults without significant hypoglycemia < 7%
Adults who take no medication or only oral medication have a long life expectancy or have no significant cardiovascular disease Target may be set lower than < 7%
Adults with limited life expectancy or advanced micro- or macro-vascular disease < 8%

The ADA recommends that an A1C target should only be set below 7% if it can be achieved without significant hypoglycemia or other adverse effects.

While helpful, these targets are general guidelines. Both the ADA and the AACE emphasize that A1C goals should be individualized based on factors such as:

  • Age
  • Length of time you’ve had diabetes
  • How well you comply with your treatment plan
  • Your risk of developing complications from hypoglycemia

However, for most people, a lower A1C is ideal so long as they’re not having frequent bouts of low blood sugar. Some people are able to substantially lessen their risk of complications from diabetes if they can keep their A1C under 7%.

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Is The Everlywell Hba1c Test A Good Option For Me

Our HbA1c Test is a great option if youâre looking for a convenient and easy way to see how well your blood sugar has been controlled over the last 90 days. Our at-home HbA1c Test only requires a small blood sample from a quick finger prick. All you do is prick your finger and mail your sample to a certified laboratory using a prepaid shipping label.

When your results are ready, youâll receive a secure digital report thatâs easy to understand. Youâll get to see how well your blood sugar levelsâas indicated by HbA1câhave been controlled over the last three months, and can choose to share your results with your healthcare provider to start a conversation with them about recommended next steps.


1. What is diabetes. International Diabetes Federation. URL. Accessed March 25, 2021.

2. Hemoglobin A1C Test. Medline Plus. URL. Accessed March 25, 2021.

3. Bonora E, Tuomilehto J. The pros and cons of diagnosing diabetes with A1C. Diabetes Care. 2011 34 Suppl 2:S184-S190.

4. Katwal PC, Jirjees S, Htun ZM, Aldawudi I, Khan S. The Effect of Anemia and the Goal of Optimal HbA1c Control in Diabetes and Non-Diabetes. Cureus. 2020 12:e8431. Published 2020 Jun 3.

5. A1C test. Mayo Clinic. URL. Accessed March 25, 2021.

Can I Take The Test At Home

The FDA has approved or cleared a number of over-the-counter hemoglobin A1c test kits that you can use at home. At-home versions of the hemoglobin A1c test may not be as accurate as tests that are performed in a lab. But they offer a convenient alternative to testing in a medical office which may be useful for some patients.

Your doctor can advise you whether taking the test at home would be right for you and may be able to recommend a specific brand.

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What Is A Hemoglobin A1c Test

A hemoglobin A1c test measures the amount of blood sugar attached to hemoglobin. Hemoglobin is the part of your red blood cells that carries oxygen from your lungs to the rest of your body. An HbA1c test shows what the average amount of glucose attached to hemoglobin has been over the past three months. It’s a three-month average because that’s typically how long a red blood cell lives.

If your HbA1c levels are high, it may be a sign of diabetes, a chronic condition that can cause serious health problems, including heart disease, kidney disease, and nerve damage.

Other names: HbA1c, A1c, glycohemoglobin, glycated hemoglobin, glycosylated hemoglobin

Oral Glucose Tolerance Test

Is Fasting Required For Hba1c Test?

This test is not now usually used to diagnose diabetes. However, the test may be done if it is thought your body doesn’t control glucose levels normally but not badly enough to be called diabetes. This is referred to as pre-diabetes . The test may also be used to see whether a woman has developed diabetes associated with pregnancy.

For this test, you fast overnight. In the morning you are given a drink which contains 75 g of glucose. A blood sample is taken two hours later. Normally, your body should be able to deal with the glucose and your blood level should not go too high. A glucose level of 11.1 mmol/L or more in the blood sample taken after two hours indicates that you have diabetes. See the separate leaflet called Glucose Tolerance Test for more details.

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Hba1c To Diagnose Diabetes

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

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

Is There Anything Else I Need To Know About Fasting Before A Blood Test

Be sure to talk to your health care provider if you have any questions or concerns about fasting.

You should talk to your provider before taking any lab test. Most tests dont require fasting or other special preparations. For others, you may need to avoid certain foods, medicines, or activities. Taking the right steps before testing helps ensure your results will be accurate.

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What Is Glycated Haemoglobin

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

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

What Are The Symptoms Of A High A1c Test Level

Diabetes Blood Test Results Explained | A1C and Fasting Blood Sugar

Sometimes there are NO symptoms! That is probably one of the scariest things about diabetes, your sugar can be high for a while and you may not even know it. When your blood sugar goes high and stays high for longer periods of time you may notice the following:

  • tired, low energy, particularly after meals
  • feel very thirsty
  • you may be peeing more than normal, waking a lot in the middle of the night to go
  • dry, itchy skin
  • crave sugar, hungrier than normal
  • blurred vision, may feel like you need new glasses
  • tingling in feet or hands
  • cuts or sores take a long time to heal or dont heal well at all
  • frequent infections

When your blood sugar is high, this means the energy that you are giving your body isnt getting into the cells. Think about a car that has a gas leak. You put gas in, but if the gas cant get to the engine, the car will not go. When you eat, some of the food is broken down into sugar and goes into your bloodstream. If your body cant get the sugar to the cells, then your body cant go. Some of the sugar that is building up in the blood, you end up peeing out. When you pee out some of your sugar, you will see dehydration, increased risk of infection, and weight loss. Ultimately, your cells dont get the energy they need and your body starts to breakdown. Medication and/or lifestyle changes can help to get your body up and running properly again.

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Which Is More Important: The A1c Test Or Fasting Glucose Level

With all due respect to the other people who have answered, âNeitherâ as both are IMO as much âdifferentâ as they are equally important for both the patient and the physician. While the A1C test, which measures an average glucose level over a period of about 3 months, to wit : Glycated hemoglobin is a form of hemoglobin that is measured primarily to identify the three-month average plasma glucose concentration. The test is limited to a three-month average because the lifespan of a red blood cell is four months. Wikipedia and the fasting glucose level just gives you a snapshot of a single moment in time, after consuming No Liquids for â8-hoursâ before the blood draw⦠though itâs also 8â10 hrs in some journals, and Iâm not so sure if 10â12+ hours necessarily makes that much more difference. Frequently, if one tests somewhat high for 2 or more fasting levels, or the levels are rising, then the physician may very well order the A1C Not only can the A1C help diagnose diabetes, but many physicians may use it to also use it post diagnosis to monitor how well the diabetic patient is participating in controlling their diabetes. Nat, just my diabetic $.02 worthContinue reading > >

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