what should the patient report to the doctor before an oral glucose tolerance test?

by Prof. Saige Watsica 9 min read

Glucose tolerance test - Mayo Clinic

23 hours ago  · Glucose tolerance test. For this test, you should not eat anything before going to the doctor in the morning. In other words, you should not have breakfast, and you should eat your last meal the evening before. This also applies to all drinks with the exception of water. First of all, blood is taken to determine your baseline blood sugar level. >> Go To The Portal


Your doctor may ask you to make sure you consume at least 150 grams of carbohydrates each day in the three days before your glucose tolerance test. If you take any prescription medications or over-the-counter drugs, be sure to discuss these with your doctor before you take the test.

Full Answer

How to prepare for oral glucose tolerance test?

– Preparation for oral glucose tolerance test begins 3 days prior to the stipulated date. You will be advised to consume a diet containing at least 150 gm of carbohydrates for at least 3 days. You will be advised to fast midnight onwards on the night before the test.

What can affect the accuracy of the glucose tolerance test?

Various factors can affect the accuracy of the glucose tolerance test, including illness, activity level and certain medications. If you're being tested for gestational diabetes, your doctor will consider the results of each blood glucose test.

How to do glucose tolerance test for children?

After that you drink a large glass of concentrated sugar solution. In the glucose tolerance test, 75 g of glucose are dissolved in 250 to 300 ml of water. The amount given to children is based on their body weight. If the test is being done to confirm suspected diabetes, blood is drawn again after two hours and the blood sugar level is measured.

What is the normal range for glucose tolerance test?

If you're being tested for type 2 diabetes, two hours after drinking the glucose solution: A normal blood glucose level is lower than 140 mg/dL (7.8 mmol/L). A blood glucose level between 140 and 199 mg/dL (7.8 and 11 mmol/L) is considered impaired glucose tolerance, or prediabetes.

Which instruction should you give to a patient before an oral glucose tolerance test?

Do not eat or drink anything after midnight on the night before your test. When you get up in the morning, you may take your medication, but take it only with plain water. Do not drink coffee or eat anything for breakfast. Bring a book or something to do with you to the lab because you will be there for 3 hours.

What should I do before my glucose test?

DO NOT eat or drink anything (other than sips of water) for 8 to 14 hours before your test. (You also cannot eat during the test.) You will be asked to drink a liquid that contains glucose (75 g). You will have blood drawn before you drink the liquid, and again 2 more times every 60 minutes after you drink it.

What instructions should be given to a patient before a random glucose is drawn?

Remember not to eat or drink anything for at least 8 hours before this test. After this test, you'll drink a sugary drink and have your blood drawn to obtain your glucose levels three times — after 1, 2, and 3 hours.

How do nurses prepare clients for glucose tolerance test?

Patient Preparation Instruct the patient to fast for at least 8 hr before the standard oral and standard gestational GTTs and not to consume any caffeinated products or chew any type of gum before specimen collection for the test; these factors are known to elevate glucose levels.

What can I eat before glucose tolerance test?

Eat a meal low in carbohydrates before this test. Example of foods to eat for breakfast would be eggs, cheese, bacon and or sausage. Avoid breads, cereals and fruit juices. Example of foods for lunch would be lettuce/salad with any kind of meat.

Why do you carb load before glucose tolerance test?

The test is very similar to the 1 hour test, but it is longer. Before your test, you will be asked to follow a diet that is high in carbohydrates to prepare your metabolism. This makes the test more accurate. Please do a “carbohydrate loading” diet for 3 days before you come for the test.

What are the nursing responsibilities when taking blood glucose?

It is usually the responsibility of the nurse to perform blood glucose readings. As with any clinical procedure, ensure that you understand the patient's condition, the reason for the test, and the possible outcomes of the procedure.

What should you not do before a fasting glucose test?

If your health care provider has told you to fast before a blood test, it means you should not eat or drink anything, except water, for several hours before your test. When you eat and drink normally, those foods and beverages are absorbed into your bloodstream.

What is RBS report?

A Random Blood Sugar or RBS test is one of the several tests that measure blood glucose levels. An RBS is performed to measure blood glucose levels regardless of when you last ate; random measurements are taken throughout the day to help diagnose diabetes.

Do you need to fast for oral glucose tolerance test?

For the three-hour test: You will be asked to come to the test fasting — not having had anything to eat or drink for the previous eight hours. A fasting blood sugar will be obtained. You'll drink about 8 ounces (237 milliliters) of a glucose solution containing 3.5 ounces (100 grams) of sugar.

What is oral glucose tolerance test used for?

Clinical Significance The glucose tolerance test is given to determine how quickly glucose is cleared from the blood. The test is used to test for diabetes, insulin resistance, impaired beta-cell function, reactive hypoglycemia, acromegaly, and other disorders of carbohydrate metabolism.

Can I drink water before GTT test?

DO NOT eat or drink anything except WATER for at least 8 hours before the test. You may drink plain water ONLY. Do NOT drink coffee, tea, soda (regular or diet) or any other beverages. Do NOT smoke, chew gum (regular or sugar-free) or exercise.

Blood Glucose Test: Levels & What They Mean - Cleveland Clinic

Glucose Tolerance Test(GTT) Test - Normal Range, Procedure ... - Portea

Why is the OGTT test so sensitive?

Lack of insulin or insulin resistance causes higher than normal levels of glucose in the blood. The OGTT is a highly sensitive test that can detect imbalances that other tests miss. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) recommends the OGTT for the following purposes: 2 .

How long before a blood test can you drink water?

You will need to stop eating and drinking eight to 12 hours before the test (time spent sleeping counts); follow your doctor's advice. You can take the occasional sip of water if desired.

How long after a meal can you get insulin?

For gestational diabetes, ACOG recommends that insulin treatment be started when your fasting blood glucose exceeds 95 mg/dL and/or your blood glucose two hours after a meal exceeds 120 mg/dL. Take time to understand your doctor's recommendations and ask any questions you may have.

What is the OGTT?

The OGTT evaluates how the body manages glucose after a meal. Glucose is a type of sugar produced when the body breaks down carbohydrates consumed in food. Some of the glucose will be used for energy; the rest will be stored for future use.

What hormones control the amount of glucose in the blood?

The amount of glucose in your blood is controlled by the hormones insulin and glucagon . If you have too much, the pancreas secretes insulin to help cells absorb and store glucose. If you have too little, the pancreas secretes glucagon so that stored glucose can be released back into the bloodstream.

What is the purpose of OGTT?

The oral glucose tolerance test (OGTT), also known as the glucose tolerance test, gauges the body’s ability to metabolize sugar (glucose) and clear it from the bloodstream. The test requires you to drink a syrupy solution after a period of fasting. A blood sample is then drawn to determine whether you are metabolizing glucose as you should be.

What is taken on the day of a blood test?

On the day of the test, after signing in and confirming your insurance information, you will be taken to an examination room where your height and weight will be recorded. Your temperature and blood pressure may also be taken.

What are the two types of glucose tolerance tests?

What types of glucose tolerance tests are there? There are two types of glucose tolerance tests: a short version called the glucose challenge test, and a full glucose tolerance test. The short version is easier to do and serves as a preliminal test to determine someone's risk of diabetes or gestational diabetes.

How much glucose is dissolved in water for a glucose tolerance test?

The blood is drawn from a vein or your fingertip or earlobe. After that you drink a large glass of concentrated sugar solution. In the glucose tolerance test, 75 g of glucose are dissolved in 250 to 300 ml of water. The amount given to children is based on their body weight. If the test is being done to confirm suspected diabetes, ...

What is an OGTT test?

Last Update: October 22, 2020; Next update: 2023. Oral glucose tolerance tests (OGTT) are used to measure how well the body can process a larger amount of sugar. If the blood sugar measured in the test is above a certain level, this could be a sign that sugar is not being absorbed enough by the body’s cells.

How often is blood drawn for gestational diabetes?

When testing for gestational diabetes, blood is drawn twice – first after one hour and then again after another two hours.

What is a glucose tolerance test?

What is Glucose Tolerance Test? Glucose tolerance test (GTT) is a screening test performed in order to determine the response of your body to glucose. It is also known as the Oral glucose tolerance test (OGTT). The two organs intrinsically involved in the metabolism and homeostasis of glucose are the pancreas and liver.

Why is glucose tolerance important in pregnancy?

It is important to diagnose and correct gestational diabetes because hyperglycemia in pregnancy is associated with an adverse prognosis both for the mother and the child. Glucose tolerance test is indicated in non-pregnant women with the polycystic ovarian disease (PCOD) to ascertain their glycemic status.

What is the result of insulin-dependent diabetes mellitus?

The result is same-increased blood sugar levels. Diabetes can be broadly classified into the following types-. Type 1 diabetes also known as insulin-dependent diabetes mellitus (IDDM). In this case, the beta cells of the pancreas which produce insulin are destroyed due to autoimmune irregularity.

How much glucose does a plant produce?

For a healthy adult, normal blood sugar levels are between 4.0 to 5.4 mmol/L when fasting and up to 7.8 mmol/ 2 hours after eating.

What is Type 2 diabetes?

Type 2 diabetes -also known as non-insulin dependent diabetes mellitus (NIDDM). In this scenario, the cells of your body become resistant to the effects of insulin. It’s the most common type of diabetes.

What is the difference between endogenous and exogenous insulin?

Insulin keeps the blood sugar levels within the normal range. This is known as endogenous insulin. Exogenous insulin is used therapeutically in patients suffering from diabetes. Diabetes – Diabetes is a disease in which your body either doesn’t make insulin or your body’s ability to utilize insulin is impaired.

When to check glucose levels during pregnancy?

Glucose tolerance test is repeated at 6–8 weeks and 12 weeks after delivery.

Why is my SP's GT exam blocked?

If an eligible SP has not been assigned to GT and less than 1 hour and 40 minutes remains in the session, then the SP’s GT exam will automatically be blocked once the SP is assigned to phlebotomy because there is not enough time to complete the entire exam.

Who introduces the SP to the OGTT exam?

The coordinator will introduce the SP to the OGTT examination and briefly explain the examination process. The coordinator can answer any general questions the SP has about venipuncture or the OGTT. However, the entire MEC staff must be prepared to answer all the questions the SP poses about the OGTT procedure and must convince the SP of the importance of participating in the OGTT component of the examination.

What are the exclusion criteria for phlebotomy?

The phlebotomist will ask SPs aged 12-59 the shared exclusion pregnancy question if the question has not already been asked elsewhere in the MEC. Hemophilia and chemotherapy safety exclu sion questions are asked and fasting status is assessed in phlebotomy as a prelude to the initial venipuncture examination. If the SP refuses one or more of the blood tubes, then he or she is excluded. The other two exclusion criteria are listed in the first screen of the first section of the OGTT examination.

How long do diabetics have to fast for phlebotomy?

Diabetics taking insulin who are assigned to morning sessions are asked to fast for 9 hours so these SPs will be assigned to phlebotomy as the highest priority. They are not eligible for the GTT.

Why is NHANES added to the examination protocol?

Because of the increasing occurrence of diabetes in younger ages, NHANES has added this component to the examination protocol to reassess the prevalence of diabetes and impaired glucose tolerance (IGT) in the U.S. population.

What are the safety exclusion questions on Trutol?

The first question asks the SP if he or she is taking insulin, and the second question asks if he or she is taking oral medications for diabetes. The insulin question is asked during the household interview. The oral medications question may be asked during the household interview, but in the event that it is not, then it is asked in the OGTT examination. Only a “Yes” response to either question will exclude the SP from the OGTT examination.

What happens if a SP refuses to draw blood?

If an SP refuses one or more blood collection tubes or the phlebotomist is unable to draw any blood tubes during the phlebotomy examination, then the SP is blocked from the GT component.

Why It's Done

Risks

  • The risks associated with obtaining a blood sample are slight. After your blood is drawn, you may experience bruising or bleeding. You may also feel dizzy or lightheaded. In some cases, infection after your procedure is possible.
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How You Prepare

  • Food and medications
    It's important to eat and drink normally in the days leading up to the glucose tolerance test. Let your doctor know if you're ill or taking any medications, as these factors can affect the results of your test.
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What You Can Expect

  • Before the procedure
    For eight hours before the test, you won't be able to eat or drink anything. You might want to fast overnight and schedule the test for early the following morning.
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Results

  • Results of the oral glucose tolerance test are given in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L).
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Clinical Trials

  • Explore Mayo Clinic studiesof tests and procedures to help prevent, detect, treat or manage conditions.
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Purpose of Test

Risks and Contraindications

Before The Test

During The Test

After The Test

Interpreting The Results

  • Your healthcare provider should receive the test results within two to three days. Along with the results will be reference ranges with high and low numeric values. Anything between the high and low values is considered normal. Anything outside of the reference range is either considered abnormally high (often denoted with the letter "H") or abnorm...
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