Glucose tolerance test preparation. How to conduct a glucose tolerance test - indications for the study and interpretation of the results. Classification of glucose tolerance methods

A glucose tolerance test has recently been included in the list of mandatory tests for pregnant women. All women are recommended to take a glucose tolerance test at 24-28 weeks of pregnancy. However, if the pregnant woman is at risk for gestational diabetes, then the test is carried out at the first visit to the antenatal clinic.

Risk factors for gestational diabetes: diabetes in close relatives, obesity, diabetes during a previous pregnancy, macrosomia of a previous child (newborn weight more than 4 kilograms).

The glucose tolerance test raises many questions for expectant mothers, as doctors usually do not explain why it is needed, how to take it correctly, and what result is considered normal.

Glucose tolerance test: why is it needed.

A woman's body reacts differently to pregnancy. In some expectant mothers, from the second half of pregnancy, a violation of glucose metabolism begins, and the level of sugar in the blood on an empty stomach often remains normal.

It is not dangerous for a woman's health and after childbirth everything returns to normal. However, the child in this situation receives an excess amount of sugar and may be too large at the time of delivery.

It is known that the birth of a large child increases the risk of complications in childbirth, including birth injuries and surgical interventions.

A glucose tolerance test is needed in order to detect a violation of sugar metabolism, the so-called gestational diabetes or diabetes in pregnancy, in time, prescribe treatment for a woman and prevent possible complications.

Preparing for a glucose tolerance test.

Three days before the test, you must eat your usual food, that is, stick to your usual diet. 24 hours before the test, it is necessary to exclude physical activity, smoking.

Basic preparation for a glucose tolerance test involves fasting for 8-12 hours prior to the test, but fasting should not last more than 14-16 hours.

In acute diseases, for example, SARS, influenza, you need to wait for a full recovery, otherwise the test results may be inaccurate. By the way, severe stress can also affect the results of the analysis.

Find out in advance if the laboratory will give you a ready-made glucose solution or if you need to prepare it. Public and some private laboratories generally offer to bring a ready-made glucose drink with you.

In the pharmacy you need to buy 75 grams of glucose powder. Before going to the laboratory in the morning, you need to dilute glucose in 300 ml of water. To make the drink easier to drink (it is cloyingly sweet), you can add freshly squeezed juice of half a lemon to the solution.

Glucose tolerance test: how to pass.

There are two main tests for gestational diabetes, one of them is screening, that is, it simply predicts the development of diabetes, and the other is diagnostic. Screening does not make a diagnosis; if abnormalities are found, a diagnostic test is recommended.

In principle, these two tests do not differ much in terms of the method of conducting; for screening, you need to drink 50 grams of glucose, for a diagnostic test - 75 or 100 grams. Doctors usually suggest that pregnant women immediately undergo a diagnostic test with a load of 75 grams of glucose.

The test is carried out in the morning. On an empty stomach, a blood test is taken from a vein, after which the pregnant woman should drink glucose in small sips for several minutes.

Repeated blood sampling is carried out after two hours. This time, it is desirable for the expectant mother to be at rest (lie down, sit), not to be nervous, not to smoke. You can't eat anything, you can drink water.

Glucose tolerance test: normal.

If the lab performs a glucose tolerance test, the rates will be listed on the test form you receive. Most labs, especially government labs, simply do two blood sugar tests and indicate when they are done.

That is, you will have two blood sugar results, for example, at 8 o'clock and at 10 o'clock. According to the World Health Organization, fasting glucose levels should not exceed 5.5, and two hours after taking 75 grams of glucose, its blood level should not exceed 7.8 mmol / l.

The test is considered positive if one or both of the indicators exceed the norm. If the result is positive, the glucose tolerance test is recommended to be repeated. With two positive results, a diagnosis of gestational diabetes is made.

The normal range in different medical institutions may vary, so it is better to interpret the results of the analysis together with your doctor. But even if your glucose tolerance test values are indeed out of the normal range, this is not a reason to panic. Compliance with the recommendations of the doctor will prevent possible complications and give birth to a healthy child.

Glucose tolerance test (OGTT - Oral Glucose Tolerance Test), otherwise called oral glucose tolerance test, used in the diagnosis of diabetes mellitus.

It consists in administering a high dose of glucose to the patient and then studying the reaction of the body - how quickly the blood sugar level is restored and how quickly insulin is released.

Oral glucose tolerance test allows diagnosing metabolic diseases such as diabetes mellitus, as well as diabetes mellitus in pregnant women.

Relationship between glucose and insulin

Glucose plays a very important function in the body - it is the main source of energy. All types of carbohydrates that we consume are converted into glucose. Only in this form they can be used by the cells of the body.

Therefore, during evolution, numerous mechanisms have been formed that regulate its concentration. Many hormones affect the amount of available sugar, one of the most important is insulin.

Insulin is produced in the beta cells of the pancreas. Its functions are primarily to transport glucose molecules from the blood to cells, where they are converted into energy. Besides, hormone insulin stimulates the storage of sugar in cells, and, on the other hand, inhibits the process gluconeogenesis(synthesis of glucose from other compounds, such as amino acids).

All this leads to the fact that the amount of sugar in the blood serum decreases, and in the cells it increases. If there is not enough insulin in the blood or tissues are resistant to its action, the amount of sugar in the blood rises, and the cells receive too little glucose.

In a healthy body, after the administration of glucose, the release of insulin from the cells of the pancreas occurs in two stages. First fast phase lasts up to 10 minutes. Then insulin, accumulated earlier in the pancreas, enters the bloodstream.

IN next phase insulin is made from scratch. Therefore, the process of its secretion takes up to 2 hours after the administration of glucose. However, in this case, more insulin is produced than in the first phase. It is the development of this process that is studied in glucose tolerance test.

Performing a Glucose Tolerance Test

Research can be done in almost any laboratory. First, blood is taken from the cubital vein to study the initial glucose level.

Then, within 5 minutes, you should drink 75 grams of glucose dissolved in 250-300 ml of water (ordinary sugar syrup). The patient then waits in the waiting room for further blood samples to be taken for analysis.

The glucose tolerance test is primarily used to diagnosis of diabetes and also helps in the diagnosis of acromegaly. In the latter case, the effect of glucose on the decrease in growth hormone levels is evaluated.

An alternative to oral glucose is intravenous glucose. During this study, glucose is injected into a vein for three minutes. However, this type of study is rarely done.

The glucose tolerance test itself is not a source of discomfort for the patient. During blood sampling, a slight pain is felt, and after taking a glucose solution, you can experience nausea and dizziness, increased sweating, or even loss of consciousness. These symptoms, however, are very rare.

There are different types of glucose tolerance tests, but they all include the following steps:

fasting blood test;
the introduction of glucose into the body (the patient drinks a solution of glucose);
another measurement of blood glucose levels after consumption;
depending on the test - another blood test after 2 hours.

Most often, 2- and 3-point tests are used, sometimes 4- and 6-point tests. 2 point glucose tolerance test means that the level of glucose in the blood is examined twice - before drinking a glucose solution and an hour after.

The 3-point glucose tolerance test involves another blood sample 2 hours after ingesting the glucose solution. In some tests, the glucose concentration is studied every 30 minutes.

The patient during the study must be in a sitting position, do not smoke or drink liquids, and also report any medications taken or existing infections before the start of the study.

A few days before the test, the subject should not change diet, lifestyle, increase or decrease physical activity.

How to prepare for a glucose tolerance test

The first very important requirement is that the glucose tolerance test should be done on an empty stomach. This means that you should not eat anything for at least 8 hours before taking blood. You can only drink clean water.

In addition, for at least 3 days before the test, you must eat a complete diet (for example, without restricting carbohydrate intake).

It is also necessary to determine with the doctor who ordered the study which of the drugs taken on an ongoing basis can increase glucose levels (in particular, glucocorticoids, diuretics, beta-blockers). Probably, their reception will need to be suspended before execution OGTT studies.

Oral glucose tolerance test in pregnancy

This glucose test is done between 24 and 28 weeks of pregnancy. Pregnancy itself predisposes to the development of diabetes. The reason is a significant increase in the concentration of hormones (estrogens, progesterone), especially after 20 weeks.

This leads to an increase in tissue resistance to the effects of insulin. As a result, the concentration of glucose in the blood serum exceeds the permissible norm, which can be the cause of formidable complications of diabetes mellitus, both in the mother and in the fetus.

Test for glucose tolerance during pregnancy is carried out a little differently. First, a woman should not be on an empty stomach. Arriving at the laboratory, she also donates blood to check the initial level of sugar. Then the expectant mother should drink 50 g of glucose (that is, less) within 5 minutes.

Secondly, the last measurement of the sugar level in the glucose tolerance test during pregnancy is performed 60 minutes after the administration of glucose.

When the test result is greater than 140.4 mg/dL, it is recommended to repeat the test with a 75 g glucose load and glycemic measurements 1 and 2 hours after ingestion of the glucose solution.

Norms of the glucose tolerance test

The result of the glucose tolerance test is presented in the form of a curve - a graph that displays fluctuations in blood glucose levels.

Test norms: in the case of a 2-point test - 105 mg% on an empty stomach and 139 mg% after 1 hour. A result between 140 and 180 mg% may indicate a pre-diabetic condition. A result above 200 mg% means diabetes. In such cases, it is recommended to repeat the test.

If after 120 minutes the result is between 140-199 mg/dL (7.8-11 mmol/L), low glucose tolerance is diagnosed. This is the state of pre-diabetes. You are diagnosed with diabetes when your glucose concentration is greater than 200 mg/dL (11.1 mmol/L) two hours after the test.

In the case of a 50 gram glucose test (during pregnancy), the sugar level after one hour should be less than 140 mg/dL. If higher, it is necessary to repeat the test with 75 g of glucose using all the rules for conducting it. If, two hours after a load of 75 grams of glucose, its concentration is more than 140 mg / dl, gestational diabetes is diagnosed.

It is worth remembering that laboratory standards may vary slightly in different laboratories, so the result of your study should be discussed with the attending physician.

When to do a glucose tolerance test

Glucose tolerance test carried out in cases where:

there are signs that the person has diabetes mellitus or impaired glucose tolerance;
after receiving an incorrect result of a fasting glucose test;
if there are signs of metabolic syndrome (abdominal obesity, high triglycerides, high blood pressure, insufficient HDL cholesterol);
in pregnant women with an incorrect fasting glucose test result;
there is a suspicion of reactive hypoglycemia;
any woman between 24 and 28 weeks pregnant.

The oral glucose tolerance test is important because of its ability to diagnose such a serious disease as diabetes mellitus. Used when, in other studies, the results diagnosing diabetes are inconclusive or when the blood glucose level is in the borderline zone.

The level of glucose in the blood is an important indicator of the functioning of the internal environment of the body. Deviation of the value from the norm in one direction or another may not be accompanied by any clinical symptoms, but manifest itself already against the background of significant damage to various organs. Therefore, a glucose tolerance test was developed and successfully introduced into clinical practice, allowing timely diagnosis of the preclinical period of diabetes and its latent forms.

What is a glucose tolerance test

Glucose tolerance test (GTT) is a laboratory method for diagnosing various disorders of glucose metabolism in the human body. With the help of this study, it is possible to establish a diagnosis of type 2 diabetes mellitus, impaired glucose tolerance. It is used in all doubtful cases, with borderline glycemic values, as well as in the presence of signs of diabetes against the background of normal blood sugar levels.

GGT assesses the ability of the human body to break down and assimilate glucose components by cells of organs and tissues.

The method consists in determining the concentration of glucose on an empty stomach, then 1 and 2 hours after the glycemic load. That is, the patient is asked to drink 75 grams of dry glucose dissolved in 200-300 milliliters of warm water for 3-5 minutes. In overweight individuals, an additional amount of glucose is needed, calculated from the formula 1 gram per kilogram, but not more than 100.

In order to better tolerate the resulting syrup, it is possible to add lemon juice to it. In seriously ill patients who have had acute myocardial infarction, stroke, status asthmaticus, it is advisable not to administer glucose; instead, a small breakfast containing 20 grams of easily digestible carbohydrates is allowed.

To complete the picture, blood sugar measurements can be taken every half an hour (5-6 times in total). This is necessary for compiling a glycemic profile (sugar curve graph).

The research material is 1 milliliter of blood serum taken from the venous bed. It is generally accepted that it is venous blood that is the most informative and provides accurate and reliable indicators in accordance with international standards. The time required to complete the test is 1 day. The study is carried out under appropriate conditions, in compliance with the rules of asepsis, and is available in almost all biochemical laboratories.

GTT is a highly sensitive test with virtually no complications or side effects. If any, they are related to the reaction of the patient's unstable nervous system to the puncture of the vein and the taking of a blood sample.

A second test is allowed no earlier than 1 month later.

Types of glucose tolerance test

Depending on the method of introducing glucose into the body, the glucose tolerance test is divided into two types:

oral (inside, through the mouth);
parenteral (intravenous, injection).

The first method is the most common, due to its less invasiveness and ease of execution. The second is resorted to involuntarily with various disorders of the processes of absorption, motility, evacuation in the gastrointestinal tract, as well as in conditions after surgical interventions (for example, gastric resection).

In addition, the parenteral method is effective for assessing the tendency to hyperglycemia in first-line relatives of patients with type 1 diabetes mellitus. This can additionally determine the concentration of insulin in the first few minutes after the injection of glucose.

The technique of injectable GTT is carried out as follows: for 2-3 minutes, a 25-50% glucose solution (0.5 grams per 1 kilogram of body weight) is injected intravenously into the patient. Blood samples for measuring levels are taken from another vein at 0, 10, 15, 20, 30 minutes after the start of the study.

Then a graph is drawn up, which displays the concentration of glucose according to the time period after the carbohydrate load. Clinical and diagnostic value is the rate of decrease in sugar levels, expressed as a percentage. On average, it is 1.72% per minute. In older and elderly people, this value is slightly less.

Any type of glucose tolerance test is performed only with the direction of the attending physician.

Sugar curve: indications for GTT

The test allows you to identify the latent course of hyperglycemia or prediabetes.

It is possible to suspect such a condition and prescribe GTT after the sugar curve is determined in the following cases:

the presence of diabetes in close relatives;
obesity (body mass index above 25 kg/m2);
in women with pathology of reproductive function (miscarriage, premature onset of labor);
the birth of a child with developmental anomalies in history;
arterial hypertension;
lipid metabolism disorders (hypercholesterolemia, dyslipidemia, hypertriglyceridemia);
gout;
episodes of increased glucose levels in response to stress, illness;
cardiovascular diseases;
nephropathy of unknown etiology;
liver damage;
established metabolic syndrome;
peripheral neuropathies of varying severity;
frequent pustular skin lesions (furunculosis);
pathology of the thyroid gland, adrenal glands, pituitary gland, ovaries in women;
hemochromatosis;
hypoglycemic conditions;
the use of drugs that increase blood glycemia;
age over 45 years (with a frequency of research 1 time in 3 years);
3rd trimester of pregnancy for the purpose of preventive examination.

GTT is indispensable in obtaining a questionable result of a routine blood test for glucose.

Rules for preparing for the test

Glucose tolerance test should be carried out in the morning, on an empty stomach (the patient should stop eating at least 8 hours, but not more than 16).

Water consumption is allowed. At the same time, during the previous three days, you should follow the usual regime of physical activity, get enough carbohydrates (at least 150-200 grams per day), completely stop smoking and drinking alcoholic beverages, do not overcool, avoid psycho-emotional unrest.

In the diet on the evening before the study, 30-60 grams of carbohydrates must be present without fail. It is strictly forbidden to drink coffee on the day of the study.

While taking a blood sample, the patient's position should be lying down or sitting, in a calm state, after a short rest (5-10 minutes). In the room where the study is carried out, an adequate temperature regime, indicators of humidity, illumination and other hygiene requirements must be observed, which can only be ensured in a laboratory or manipulation room of a hospital inpatient department.

In order for the sugar curve to be objectively displayed, the GTT should be rescheduled if:

the person under study is in the prodromal or acute period of any infectious and inflammatory disease;
during the last days surgery was performed;
there was a severe stressful situation;
the patient is injured;
the intake of certain medications (caffeine, calcitonin, adrenaline, dopamine, antidepressants) was noted.

Incorrect results can be obtained with potassium deficiency in the body (hypokalemia), impaired liver function and endocrine system organs (hyperplasia of the adrenal cortex, Cushing's disease, hyperthyroidism, pituitary adenoma).

The rules for preparing for the parenteral GTT method are similar to those for taking glucose through the mouth.

Glucose tolerance in men and women

The World Health Organization (WHO) recommends that the following blood sugar levels be considered normal:

on an empty stomach - less than 6.1 mmol / l (<109,8 мг/дл);
1 hour after oral GTT - less than 7.8 mmol / l (<140,4 мг/дл);
2 hours after oral GTT - less than 7.8 mmol / l (<140,4 мг/дл).

According to the American Diabetes Association (ADA), these values are somewhat different:

on an empty stomach - less than 5.6 mmol / l (<100,8 мг/дл);
2 hours after oral GTT - less than 7.0 mmol / l (<126 мг/дл).

Glucose tolerance is considered impaired if fasting glucose is 6.1-6.9 mmol/l, 2 hours after exercise - 7.8-11.0 mmol/l according to WHO. The values suggested by ADA are as follows: on an empty stomach - 5.6-6.9 mmol/l, after 2 hours - 7.0-11.0 mmol/l.

Women

In women, glucose levels correspond to generally accepted standards. However, these values are more subject to fluctuations during the day, due to the influence of the hormonal background, more pronounced emotional perception. Sugar can rise slightly during critical days, pregnancy, which is considered an absolutely physiological process.

Men

Men are also characterized by concentrations that do not differ from classical standards and age categories. If the subject is at risk for diabetes and all indicators are normal, it is advisable to conduct the examination at least once a year.

Children

Normal values in children under 14 years of age correspond to 3.3-5.6 mmol/l, in newborns - 2.8-4.4 mmol/l.

For children, the calculation of the required volume of dry anhydrous glucose for GTT is carried out as follows - 1.75 g per 1 kilogram of body weight, but in a total volume not more than 75 grams. If the weight of the child is 43 kilograms or more, use the usual dosage, as for adults.

The risk of developing hyperglycemia is increased in children with overweight and an additional risk factor for diabetes mellitus (burdened heredity, low physical activity, malnutrition, etc.). However, such violations are often transient and require definition in dynamics.

Glucose levels in diabetes

According to data provided by the World Health Organization, the diagnosis of diabetes mellitus is confirmed by the following indicators of glucose in the blood serum:

on an empty stomach - 7 or more mmol / l (≥126 mg / dl);
2 hours after GTT - 11.1 or more mmol/l (≥200 mg/dl).

The criteria of the American Diabetes Association are the same as above.

The diagnostic process involves repeated determinations of glycemia on other days. In the debut of a pathological condition and during its decompensation, measurements for glucose tolerance are carried out especially often.

The diagnosis is immediately made in case of the presence of classic symptoms of the disease (polydipsia, dryness in the oral cavity, increased urination, weight loss, impaired visual acuity) and with an accidental (regardless of food intake, time of day) measurement of glucose more than 11.1 mmol / l independently from eating.

Measurement of glycemia in order to confirm or exclude diabetes is not advisable to carry out:

in case of onset or aggravation of any disease, injury or surgical operation;
with short-term use of medications that increase blood sugar (glucocorticosteroids, thyroid hormones, statins, thiazide diuretics, beta-blockers, oral contraceptives, drugs for the treatment of HIV infection, nicotinic acid, alpha and beta adrenomimetics);
in patients with cirrhotic liver disease.

In the absence of unequivocal hyperglycemia, the result is confirmed by another test.

Glucose tolerance test during pregnancy

In pregnant women with previously undiagnosed diabetes mellitus, testing for gestational variant disease is performed at 24-28 weeks using a glucose tolerance test (measurement of 2-hour plasma glycemia with a load of 75-100 grams of glucose) and an assessment of diagnostic significance.

Normal blood glucose values during pregnancy are:

on an empty stomach - less than 5.1 mmol / l (<91,8 мг/дл);
1 hour after GTT - less than 10 mmol / l (<180 мг/дл);
2 hours after GTT - less than 8.5 mmol / l (<153 мг/дл).

Gestational diabetes mellitus is established when the following results are obtained:

on an empty stomach - 5.1 mmol / l or more (≥91.8 mg / dl), but less than 7.0 mmol / l (126 mg / dl);
1 hour after GTT -10 mmol/l and above (≥180 mg/dl);
2 hours after GTT -8.5 mmol/l and more (≥153 mg/dl), but less than 11.1 mmol/l (200 mg/dl).

Particular vigilance and a higher frequency of examination should be in pregnant women with the following conditions:

exceeding the permissible value of the body mass index (more than 30 kg / m2);
the presence of gestational diabetes in previous pregnancies;
genetic predisposition (immediate relatives suffer from diabetes);
the birth of a large fetus over 4 kilograms in history;
arterial hypertension (systolic blood pressure above 140 mm Hg, diastolic - above 90 mm Hg);
polycystic ovary syndrome;
dermatosis (skin growths of dark color in the axillary, cervical, inguinal folds).

the pregnant woman suffers from toxicosis, accompanied by vomiting and nausea;
a woman is forced to observe constant bed rest;
there is an active phase of inflammatory disease of the pancreas;
there are signs of an acute period of an infectious disease.

It should be borne in mind that pregnant women are prone to conditions in which glucose levels can be reduced. For example, physical activity can lead to this condition, as the body intensively consumes energy reserves.

Which doctor should I contact with test results?

After receiving the results of GTT, the patient can contact a therapist, a general practitioner to interpret the tests and clarify further tactics, or directly to an endocrinologist.

The specialist will make a conclusion, on the basis of which an additional examination may be required (for example, determining the level of glycated hemoglobin, C-peptide), clarify or refute the diagnosis, formulate recommendations regarding lifestyle modification, medication and further control of blood sugar concentration.

In other cases, a glucose tolerance test can be prescribed by nephrologists, cardiologists, gynecologists, neuropathologists and other doctors, since hyperglycemia is characterized by damage to a wide range of organs and systems.

This analysis is also ideal for self-monitoring. This study allows you to check and accurately determine the type of pathology.

The essence of the test is to introduce a certain dose of glucose into the body and take control portions of blood for. .

A glucose solution, depending on the state of health and physical capabilities of the patient, can be taken orally naturally or injected through a vein.

The second option is usually resorted to in case of poisoning and when the expectant mother has toxicosis. To get an accurate result of the study, it is necessary.

The Importance of Proper Preparation for the Glucose Tolerance Test

Both the first and second options are distorted and cannot reflect the real state of affairs.

Accordingly, protecting the body from external influences is the key to obtaining the right result. For training, it is enough to follow some simple rules, which will be discussed below.

How to prepare for the glucose tolerance test?

To get a reliable result after passing the analysis, preparatory measures must be started a few days in advance.

During this period, you need to monitor your own.

We are talking about eating only those foods that are medium or high.

Products with a reduced content for this period are best put aside. The daily dose of carbohydrates in the preparation process should be 150 g, and at the last meal - no more than 30-50 g.

Compliance is invalid. The lack of this substance in food will provoke the development (), as a result of which the data obtained will be unsuitable for comparison with subsequent samples.

What can not be eaten before the analysis and how long should there be a break after eating?

About a day before passing the glucose tolerance test, it is advisable to refuse. Everything is banned: sweets, cakes, jellies, cotton candy and many other types of favorite foods.

It is also worth excluding sweet drinks from the diet: sweetened and, from tetrapacks, Coca-Cola, Fanta and others.

To prevent, the last meal should be 8-12 hours before the time of arrival at the laboratory. longer than the specified period is not recommended, since in this case the body will suffer from hypoglycemia.

The result will be distorted readings, unsuitable for comparison with the results of blood samples taken later. During the period of "hunger strike" you can use plain water.

What can influence the results of the study?

In addition to following a certain diet, it is also important to follow some other prescriptions that can also affect glycemic levels.

To avoid distortion of indicators, observe the following points:

on the morning before the test, you can not brush your teeth or freshen your breath with chewing gum. Both in toothpaste and in chewing gum, there is one that immediately penetrates into the bloodstream, provoking development. If there is an urgent need, you can rinse your mouth after sleep with plain water;
if you had to be pretty nervous the day before, postpone the study for a day or two. in the most unpredictable way, it can affect the final result, provoking both an increase and a decrease in the level of sugar in the blood;
you should not go for a glucose tolerance test if you previously had to undergo an x-ray, a blood transfusion procedure,. In this case, you will not get an accurate result, and the diagnosis made by a specialist will be incorrect;
you should not be tested if you have a cold. Even if it is normal, it is better to wait a little before going to the laboratory. With a cold, the body works in an enhanced mode, actively producing. As a result, blood sugar levels may also rise until you feel better;
Do not take walks between blood draws. will lower your sugar levels. For this reason, during the 2 hours of stay in the clinic, it is better to be in a sitting position. In order not to be bored, you can take a magazine, newspaper, or electronic game with you from home in advance.

Compliance with the preparation rules will provide the body with protection from third-party influences that can distort the test result.

Can the patient drink water?

If it is, which does not contain flavorings and other flavorings, then you can use such a drink during the entire period of the “hunger strike” and even in the morning before taking the test.

Still or carbonated mineral water is also not suitable for use during active training.

How to prepare a glucose tolerance test solution?

Can be purchased at a regular pharmacy. It has a very affordable price and is sold almost everywhere. Therefore, there will be no problems with its purchase.

The proportion in which the powder is mixed with water may vary. It all depends on the age and condition of the patient. Recommendations regarding the choice of volumes of liquid are given by the doctor. As a rule, specialists use the following proportions.

Powder for glucose solution

Ordinary patients should consume during the test 75 g of glucose diluted in 250 ml of pure water without gas and flavors.

If we are talking about a patient, glucose is diluted at the rate of 1.75 g per kilogram of weight. If the patient weighs more than 43 kg, then the general proportion is used for him. For the proportion is all the same 75 g of glucose diluted in 300 ml of water.

In some medical institutions, the doctor himself prepares the glucose solution.

Therefore, the patient does not have to worry about the correct proportion.

If you are being tested at a public health facility, you may be required to bring water and powder to prepare the solution with you, and the doctor will take care of all the necessary steps to prepare the solution.

Norms and deviations of the test

The upper limit of the norm for the glucose tolerance test is 6.7 mmol / l, the lower limit is taken as the initial value of sugar, there is no clear lower limit of the norm for the study.

With a decrease in the load test, we are talking about all kinds of pathological conditions, they entail a violation of carbohydrate metabolism, glucose resistance. With the latent course of type 2 diabetes mellitus, symptoms are observed only when adverse conditions occur (stress, intoxication, trauma, poisoning).

If the metabolic syndrome develops, it entails dangerous health problems that can cause the death of the patient. These diseases include myocardial infarction, arterial hypertension, coronary insufficiency.

Other violations will be:

excessive work of the thyroid gland, pituitary gland;
all sorts of regulatory disorders;
suffering of the central nervous system;
gestational diabetes;
inflammatory processes in the pancreas (acute, chronic).

An oral glucose tolerance test is not a routine test, however, each person should know their sugar curve to determine formidable complications.

The analysis must be done with confirmed diabetes mellitus.

Who should be under special control

Sugar level

A glucose tolerance test is primarily indicated for patients who are at risk for type 2 diabetes. No less important is the analysis in pathological conditions that are permanent or periodic in nature, leading to a violation of carbohydrate metabolism, the development of diabetes.

In the area of attention are people whose blood relatives already have diabetes, are overweight, arterial hypertension and lipid metabolism disorders. An endocrinologist will prescribe a glucose test for atherosclerotic vascular lesions, gouty arthritis, hyperuricemia, and a long course of pathology of the kidneys, blood vessels, heart and liver.

The risk group also includes an episodic increase in glycemia, traces of sugar in the urine, patients with a burdened obstetric history, over the age of 45, with chronic infections, neuropathy of unknown etiology.

In the considered cases, a tolerance test must be carried out even if the fasting glucose values are within the normal range.

What can affect the results

If a person is suspected of impaired glucose resistance, insulin fails to neutralize the excess sugar, he needs to know that various factors can affect the test result. Problems with glucose tolerance are sometimes diagnosed in people without diabetes.

The reason for the decrease in tolerance will be the habit of often using sweets and confectionery, sweet carbonated drinks. Despite the active work of the insular apparatus, the level of glucose in the blood rises, resistance to it decreases. Intense physical activity, drinking alcohol, smoking strong cigarettes, psycho-emotional stress on the eve of the study can also reduce glucose tolerance.

Pregnant women have evolved a defense mechanism against hypoglycemia, but doctors believe it does more harm than good.

Glucose resistance is also associated with overweight, many diabetics are obese. If a person thinks about their health and switches to a low-carb diet:

he will get a beautiful body;
improve well-being;
reduce the chance of developing diabetes.

The indicators of the tolerance test are affected by diseases of the gastrointestinal tract, for example, malabsorption, motility.

These factors, although they are physiological manifestations, should make a person think about their health.

Changing the results for the worse should force the patient to reconsider eating habits, learn to control their emotions.

How to submit and prepare

To obtain an accurate result, proper preparation for the glucose tolerance test is important. In about three days, it is required to adhere to the use of the recommended amount of carbohydrates, but there is no need to change the usual mode of rest, work and physical activity.

Before the test, the last meal should be taken no later than 8 pm, 12 hours before the test, alcohol, smoking, and strong black coffee should be limited. It is better not to burden yourself with excessive physical activity, postpone sports and other active wellness procedures.

On the eve of the procedure, it is recommended to skip taking certain medications: hormones, diuretics, neuroleptics, adrenaline. It happens that a blood test for sugar coincides with menstruation in women, then it is better to postpone it for several days.

The results of the glucose tolerance test may be inaccurate if the biological material was taken:

during emotional experiences;
at the peak of an infectious disease;
after surgery;
with cirrhosis of the liver;
in the inflammatory process in the hepatic parenchyma.

A false result occurs in some diseases of the digestive tract, which occur with a violation of glucose consumption.

Incorrect numbers are observed with a reduced concentration of potassium in the bloodstream, disruption of the liver, and some serious diseases of the endocrine system.

Half an hour before blood sampling, the patient should sit in a comfortable position for him, think about good things, drive away bad thoughts.

It happens that for a tolerance test it is necessary to inject glucose intravenously. When and how to carry out the examination, the decision should be made by the attending physician.

How is a glucose tolerance test done?

The first time they take blood for an analysis of fasting sugar, the result of the study is taken as the initial data. After that, it is necessary to dilute dry glucose powder (300 ml of water diluted with 75 g of glucose), take the solution at a time. You can not take too much money, the exact amount of glucose is selected individually, the dosage depends on the patient's condition (weight, age, pregnancy).

Often, sugary sweet syrup, consumed on an empty stomach, provokes an attack of nausea in a person. To prevent such an unpleasant side reaction, add a little citric acid to the solution or squeeze lemon juice. If you have the same problem, buy glucose for the glucose tolerance test with lemon flavor, you also need to dilute it with 300 grams of water. You can buy the test directly at the clinic, the price is quite affordable.

After using the drug, the patient needs to take a walk near the laboratory for some time, after how long it takes to return and donate blood again, the medical worker will tell. It depends on the frequency and frequency of blood sampling for analysis.

By the way, you can conduct research at home. A similar imitation of a glucose resistance test is a blood glucose test. The patient can, without leaving home with a glucometer:

determine fasting sugar levels;
after a while, eat some carbohydrates;
test again for sugar.

Naturally, there is no decoding of such an analysis, there are no coefficients for interpreting the sugar curve. You just need to write down the initial result, compare it with the value obtained. At the next appointment with the doctor, this will help the doctor to see an accurate picture of the course of the pathology, so that in case of development, take appropriate measures.

Contraindications to the glucose tolerance test are acute infectious and inflammatory diseases, the consequences of violating this rule are to obtain a false result. In all other cases, the diagnostic procedure can be carried out without restrictions, the test is mandatory during pregnancy.

Test for glucose with load reviews can be read on the Internet is done in the morning on an empty stomach.

Sugar Curve Factors

In the laboratory, a glycemic curve obtained after a blood test for some time and reflecting the behavior of sugar in the body (decrease or increase) helps to calculate the hyperglycemic coefficient.

For diabetes, the Baudouin coefficient is calculated based on the ratio of the highest sugar level (peak value) during the analysis to the initial result in fasting blood. The norm of sugar in the blood is noted at a coefficient in the range from 13 to 1.5.

There is another coefficient, it is called postglycemic or Rafalsky. It is the ratio of blood sugar levels after drinking a glucose solution to the concentration of glucose on an empty stomach. In patients without impaired carbohydrate metabolism, the result obtained does not go beyond 0.9 - 1.04.

If a diabetic from time to time wants to independently test glucose tolerance using a portable one, he should take into account that special biochemical methods for evaluating the results of the study are used in clinics. A glucometer designed exclusively for express analysis can often give false results and confuse the patient.

How to take a glucose tolerance test is described in the video in this article.