Glucose is the main source of energy for the body's cells and the only source of energy for the brain and cells of the nervous system. A healthy body maintains a certain level of glucose in the blood. The balance of glucose in the blood depends on the hormones of the pancreas: insulin and glucagon. Insulin promotes the absorption of glucose by the body's cells and the formation of its reserves in the liver in the form of glycogen. Glucagon, on the contrary, mobilizes glucose from storage in order to, if necessary, increase blood glucose levels.
Blood sugar
When we talk about blood sugar, we mean the level of glucose - the main source of energy that ensures the normal functioning of organs and muscles.
Glucose concentration deviates from the norm in the presence of certain hormones in the body. Insulin, which is produced in the pancreas, is responsible for the decrease. And an increase in glucose levels can be triggered by several active substances: glucagon, adrenaline, norepinephrine, cortisol and corticosterone.
Such deviations cause certain pathological conditions, which are discussed below.
Symptoms of high sugar
High blood sugar can be recognized by the following symptoms:
- thirst and dry mouth;
- constant feeling of hunger;
- slow healing of wounds.
The subsequent increase in sugar leads to hyperglycemic coma, ketoacidosis and hyperosmolar coma.
Cost of tests
The price of ACS depends on the organization where the blood is drawn. The cheapest way is a government agency. In state clinics, AKS will be free or the cost will be up to 300 rubles. In private clinics, this analysis will cost from 400 rubles.
In addition, you can monitor your glucose levels without leaving home. To do this, it is enough to purchase a glucometer, the approximate cost of which is 900-1600 rubles, and the cost of testers is 50 rubles per package.
Blood test for sugar: norms
If the patient has the above symptoms, the doctor gives a referral for a blood sugar test. The norm when taken from a finger on an empty stomach is from 3.3 to 5.5 mmol/l, and after eating - 5.6-6.6 mmol/l. If the second indicator is reached when donating biomaterial on an empty stomach, then insulin sensitivity is impaired.
A reading of 6.7 mmol/l after analysis on an empty stomach indicates hyperglycemia - high blood sugar. If the symptom manifests itself chronically, then there is a high probability that the patient has diabetes. Hyperglycemia may be a sign of:
- endocrine diseases;
- disorders of the liver and hypothalamus;
- development of inflammatory processes.
A level below 3.3 mmol/l, on the contrary, is a signal of the development of hypoglycemia - a decrease in glucose levels, which can lead to seizures, headaches, and disruption of the pancreas, liver, kidneys and adrenal glands.
A blood sugar test helps detect existing pathologies.
In what cases is a glucose test usually prescribed?
Typically, glucose levels are determined when a carbohydrate metabolism disorder is suspected. The most common cause of chronic high blood glucose (hyperglycemia) is diabetes mellitus. It is important to check fasting glucose during clinical examination for healthy people, since diabetes can be asymptomatic for several years and is diagnosed already at the stage of complications.
A glucose test (otherwise called “blood sugar”) is used to screen healthy individuals, to identify patients with prediabetes and diabetes, and when examining pregnant women.
Low glucose levels (hypoglycemia) can be life-threatening, and acute hypoglycemia can lead to coma and death of brain cells.
Several sequential blood glucose measurements are taken during a glucose tolerance test. In this case, the patient is first measured on an empty stomach, and then given a so-called “sugar load”, after which the glucose level is measured after 1 and 2 hours. The glucose tolerance test (OGTT) is not performed in medical laboratory offices because the patient must be under the supervision of a physician while performing the test. The OGTT (oral glucose tolerance test) can only be done in patients whose fasting glucose level does not exceed 7 mmol/l.
How to prepare?
Preparation methods differ depending on the type of analysis:
- Glucose tolerance test. Allows you to understand how the body reacts to a sugar load. Before the test, you need to drink a sweet drink;
- Analysis for glycated hemoglobin. Determines the average sugar level over several months. Does not require special training;
- Determination of plasma glucose levels. Used in the morning on an empty stomach. 8 hours before the procedure you should not eat or drink anything except water.
Medical term
The terminology “blood sugar, sugar test” has become part of the daily speech of citizens. But among medical terminology there is no such concept as blood sugar, because sugar consists of a large number of elements. So the correct name is blood glucose test.
There are 4 methods for determining blood glucose, namely:
- Laboratory - analysis is carried out in medical institutions. The main advantage is obtaining a 100% reliable result.
- Express - carried out using a home device called a glucometer. When using this device, blood from your finger should be applied to a special test strip. You can get the result in a couple of seconds. The disadvantage is the receipt of unreliable information (error up to 20%) due to non-compliance with the rules for caring for the device.
- Load analysis – blood testing is performed in 2 stages. Read more about this method in our article.
- Glycated hemoglobin - thanks to this technique, you can determine your sugar level over the past 3 months. This method is most often used in the treatment of diabetes.
What does load analysis mean?
Glucose tolerance test is another name for ACS with stress. With this test you can find out how the body reacts to insulin, which is produced in the pancreas.
Doctors prescribe a glucose tolerance test in the following situations:
- suspected diabetes mellitus;
- polycystic ovary syndrome;
- overweight;
- metabolic syndrome (occurs when the body's cells do not respond to the produced pancreatic hormone);
- diabetes;
- pathologies in the digestive system.
ACS with load occurs in several stages, namely:
- Receiving a referral for analysis.
- Preparation as follows: do not eat 12 hours before blood sampling; tests must be taken in the morning; You cannot drink or eat during the test; 2 days before blood sampling, it is necessary to exclude fatty foods, physical activity, stress, alcohol, smoking, and taking medications.
- The clinic performs the first blood sampling from a finger.
- After the analysis, you should consume 100 grams of glucose in the form of tablets or solution (for an adult, 250 ml of liquid must be diluted with 100 grams of glucose).
- After 2 hours, another blood sample is taken from a vein.
The norm among children and adults
The norm among women and men is the same - 3.5-5.5 mmol/l (from a finger) and 3.7 - 6 mmol/l (from a vein). If the analysis needs to be done urgently, then the readings will vary between 4-7.8 mmol/l.
Newborns have glucose levels of 2.8-4 mmol/l; in older age, the norm is up to 5 mmol/l. After reaching 6 years of age, the norm of sugar concentration is identical to that of adult patients.
The glucose norm is fixed in the following table:
| Age criteria | Norm, mmol/l |
| Up to a year | 2,8-4,4 |
| Children from 1 year | 3,3-5 |
| Adults | 3,5-5,5 |
| Pregnant women | 3,8-5,8 |
Each laboratory has its own sugar norms. Therefore, the laboratory assistant or doctor must inform about the standards on the basis of which the interpretation was made.
In addition, it is worth considering a number of features when determining the norm, namely:
- diabetics: the norm is 6 mm/l or more;
- a value between 5.5-6 mm/l refers to an intermediate state - in such a situation the doctor makes a diagnosis called “impaired glucose tolerance”;
- after eating, glucose level is below 10 mm/l;
- The rate of the glycated method varies between 6.5-7% (more details in the next chapter).
How to submit?
To obtain reliable results, the patient must prepare for the analysis as follows:
- It is forbidden to eat food 8-12 hours before the test.
- You can drink regular water.
- 2 days before the ACS, you should not drink alcohol or eat fatty, fried foods.
- On ACS day, you should not brush your teeth or use chewing gum, since toothpaste and chewing gum contain sugar.
- You cannot take medications for 3 days. If such cancellation is not possible, then the patient must notify the doctor.
- The test must be taken before 9 am.
- The day before ACS, you cannot perform serious mental (physical) work.
- Smoking is prohibited on the day of the ACS (before the actual collection).
- You cannot donate blood after therapeutic procedures (for example, massage, ultrasound, x-ray).
- If colds or inflammatory diseases develop, ACS should be postponed until after recovery.
Glycation analysis
Thanks to this method, you can determine how successful your diabetes treatment is. Such an analysis must be taken once a week for 3 months in one laboratory.
Important! Doctors refer to glycation analysis as follows: A1C, HbA1C.
In addition, a glycation test is required if there are symptoms such as: slow wound healing; fatigue; fruity breath; frequent urination; sudden deterioration of vision; dryness (mouth).
First of all, the risk group includes:
- obese persons;
- pregnant women;
- persons leading a passive lifestyle;
- employees of hazardous production;
- patients who drink a lot of alcohol;
- women who have polycystic ovary syndrome (leading to infertility);
- patients with low cholesterol levels;
- heredity to diabetes.
Blood is taken from a finger at any time of the day, but doctors recommend donating blood on an empty stomach in the morning. The results will be ready in 2 days.
Important! The norm of glycated hemoglobin is 4-9%. In diabetics, these indicators are 2 times higher.
It is worth highlighting the pros and cons of this method, and let's start with the advantages:
- It is not necessary to take tests on an empty stomach.
- This method allows you to identify the disease at an early stage of development.
- The analysis is carried out quickly and without preparation.
- Accuracy of the results obtained.
- The test helps determine how well the patient controls their sugar levels.
- The results obtained do not depend on the use of medications, physical activity, or the emotional (or physical) state of the patient.
The disadvantages of the analysis are the following:
- high cost - from 500 to 2000 rubles;
- with anemia or hemoglobinopathy (impairment or change in the structure of the hemoglobin protein), the results may be inaccurate;
- This test cannot be taken in all clinics or laboratories;
- indicators increase with increased levels of thyroid hormones.
For more information about glycated hemoglobin, see the following video:
Continuous Glucose Monitoring Systems CGM
There are also systems for continuous monitoring of blood glucose levels. One of them is FreeStyleLibre. The mechanism consists of a sensor that is attached to the skin and a reading device. The sensor is replaced once every 14 days.
The Dexcom continuous monitoring system operates on a similar principle.
We should also not forget about the built-in blood sugar monitoring systems that are found in the latest models of insulin pumps. The operating system is designed in such a way that the user does not need to make any punctures, except for the place where the pump cannula is attached. The built-in sensor detects blood sugar levels and signals at dangerous glycemic thresholds. Which is very convenient at night. When blood glucose levels are low, the pump stops delivering insulin.
