Sweet topic. What is the difference between sugar, glucose, fructose and other “oses”?

What is glucose used for?

Glucose takes part in metabolism. The brain needs this substance. When there is a lack of sugar in the body, a person experiences a feeling of hunger, which is the first signal.

The benefits of glucose are as follows:

• supplies energy;
• helps fight stressful situations and depression;
• takes part in metabolic processes;
• supports normal functioning of the cardiovascular system;
• has a positive effect on the general condition.

The substance is also useful in the presence of liver diseases.

What is the normal blood glucose level?

The human body processes the substance daily. This happens during meals, since at this moment the pancreas starts working. The liver and insulin monitor the amount of sugar rising in the blood.

If a person suffers from diabetes, the necessary insulin is not produced. Insulin injections help maintain blood sugar levels.

On a note! It is especially important to maintain acceptable blood sugar levels in children with diabetes.

Many patients perform glucose tests on their own at home, without the need to constantly visit the hospital.

The performance of the body is largely determined by the sugar content. Before a person eats food, the level of the substance fluctuates between 100-120 mg/dl. After a couple of hours, the glucose concentration should not exceed 10 mg/dL. Depending on age, the permissible level of a substance in the body differs - the older the person, the higher the value will be.

A blood glucose test should be performed on an empty stomach, preferably in the morning.

Glucose is a simple sugar, the main hydrocarbon in the blood and the main source of energy for all cells.

Synonyms Russian

Blood sugar test, blood glucose test, fasting blood glucose test.

English synonyms

Blood sugar, fasting blood sugar, FBS, fasting blood glucose, FBG, fasting plasma glucose, blood glucose, urine glucose.

Research method

Enzymatic UV method (hexokinase).

Units

Mmol/L (millimoles per liter), mg/dL (mmol/L x 18.02 = mg/dL).

What biomaterial can be used for research??

Venous, capillary blood.

How to properly prepare for research?

1. Do not eat for 12 hours before the test.
2. Avoid physical and emotional stress 30 minutes before the test.
3. Do not smoke for 30 minutes before the test.

General information about the study

Glucose is a simple sugar that serves as the body's main source of energy. The carbohydrates consumed by a person are broken down into glucose and other simple sugars, which are absorbed by the small intestine and enter the blood.

Most cells in the body require glucose to produce energy. The brain and nerve cells need it not only as a source of energy, but also as a regulator of their activity, since they can function only if the glucose level in the blood reaches a certain level.

The body can use glucose thanks to insulin, a hormone produced by the pancreas. It regulates the movement of glucose from the blood into the body's cells, causing them to accumulate excess energy in the form of a short-term reserve - glycogen or in the form of triglycerides, deposited in fat cells. A person cannot live without glucose and without insulin, the content of which in the blood must be balanced.

Normally, the glucose level in the blood plasma increases slightly after a meal, while secreted insulin lowers its concentration. Insulin levels depend on the volume and composition of food taken. If the concentration of glucose in the blood drops too low, which can happen after several hours of fasting or after intense physical activity, glucagon (another pancreatic hormone) is released, which causes liver cells to transform glycogen back into glucose, thereby increasing its level in the blood .

Maintaining normal blood glucose levels is extremely important. When the glucose-insulin feedback mechanism works properly, blood glucose levels remain fairly stable. If this balance is disturbed and the blood sugar level increases, then the body seeks to restore it, firstly, by producing more insulin, and secondly, by excreting glucose in the urine.

Extreme forms of hyper- and hypoglycemia (excess and lack of glucose) can threaten the patient’s life, causing organ dysfunction, brain damage and coma. Chronically elevated blood glucose levels can cause damage to the kidneys, eyes, heart, blood vessels and nervous system. Chronic hypoglycemia is dangerous for the brain and nervous system.

Sometimes women experience hyperglycemia (gestational diabetes) during pregnancy. If left untreated, it can cause the mother to give birth to a large baby with low blood glucose levels. Interestingly, a woman who suffers from hyperglycemia during pregnancy will not necessarily have diabetes after pregnancy.

What is the research used for?

Glucose levels are important in the diagnosis of hyper- and hypoglycemia and, accordingly, in the diagnosis of diabetes mellitus, as well as for its subsequent monitoring. Sugar testing can be done on an empty stomach (after 8-10 hours of fasting), spontaneously (any time), after a meal, and can also be part of an oral glucose tolerance test (OGT).

If diabetes is diagnosed, it is recommended to perform a fasting blood glucose test or a glucose tolerance test. Moreover, for final confirmation of the diagnosis, tests should be carried out twice at different times.

Most pregnant women are tested for gestational diabetes (a temporary type of hyperglycemia) between 24 and 28 weeks of pregnancy.

Diabetics should closely monitor their blood glucose levels to adjust their tablet intake and insulin injections. It is usually necessary to determine how far the glucose concentration deviates from the norm several times a day.

Measuring glucose levels at home is usually carried out using a special device - a glucometer, into which a test strip is placed with a previously applied drop of blood from the patient’s finger.

When is this test prescribed?

• During preventive examination of patients without suspicion of diabetes, since diabetes is a disease that begins with minor symptoms. It is especially important to monitor blood glucose levels in patients with a genetic predisposition to diabetes, those with increased body weight, and those over 45 years of age.
• When diagnosing diabetes in patients with symptoms of hyper- or hypoglycemia. Symptoms of hyperglycemia or high sugar: increased thirst, increased urination, fatigue, blurred vision, increased susceptibility to infections. Symptoms of hypoglycemia or low sugar: sweating, increased appetite, anxiety, clouded consciousness, blurred vision.
• If you lose consciousness or become very weak, to see if they are caused by low blood sugar.
• If the patient has a prediabetic state (in which plasma glucose levels are higher than normal, but lower than in diabetic patients), the analysis is carried out at regular intervals.
• For people diagnosed with diabetes, a blood glucose test is prescribed in conjunction with a glycated hemoglobin (A1c) test to track changes in blood glucose levels over a long period of time.
• In some cases, a plasma glucose test may be performed in conjunction with an insulin and C-peptide test to monitor insulin production.
• Pregnant women are usually tested for gestational diabetes at the end of their pregnancy. If a woman has been diagnosed with gestational diabetes before, she is tested for glucose throughout pregnancy, as well as after childbirth.

What do the results mean?

Reference values ​​(Blood glucose norm)

Other causes of elevated glucose levels:

• acromegaly,
• severe stress (reaction to trauma, heart attack, stroke),
• chronic renal failure,
• hypercortisolism syndrome (Itsenko-Cushing),
• taking medications such as corticosteroids, tricyclic antidepressants, diuretics, epinephrines, estrogens, lithium, diphenin (Dilantin), salicylates,
• excessive consumption of high carbohydrate foods,
• hyperthyroidism,
• pancreas cancer,
• pancreatitis.

Causes of low blood glucose levels:

• adrenal insufficiency,
• alcohol abuse,
• taking medications such as acetaminophen and anabolic steroids,
• liver diseases,
• hypopituitarism,
• hypothyroidism,
• insulin overdose,
• insulinomas,
• starvation.

What foods contain glucose

The substance is present in many foods. The food consumed is broken down into fats, proteins and carbohydrates. Glucose is present in sufficient quantities in the following components:

• sweet;
• honey;
• fruits;
• bread;
• cabbage;
• sugar;
• carrot.

Boiled potatoes and corn contain glucose in the form of starch.

Properties of glucose

Physical properties

Chemical properties

Glucose is a reducing agent - it gives up electrons from the outer electronic level of atoms and reduces another substance. Glucose molecules uniting with each other produce polysaccharide products: glycogen, cellulose, starch. Glucose as a structural unit is found in more complex sugars - sucrose, lactose, maltose. Reverse cleavage of these disaccharides produces glucose and fructose.

1. Glucose reacts with an ammonia solution of silver oxide to form a silver mirror:

CH2OH-(CHOH)4-CHO+Ag2O → CH2OH-(CHOH)4-COOH + 2Ag

1. When reacting with copper hydroxide it gives a red precipitate Cu2O

CH2OH-(CHOH)4-CHO + 2Cu(OH)2 → CH2OH-(CHOH)4-СОOH + Cu2O↓ + 2H2O

1. Reduced with hydrogen to form hexahydric alcohol (sorbitol)

CH2OH-(CHOH)4-CHO + H2 → CH2OH-(CHOH)4-CH2OH

1. Fermentation processes

• lactic acid fermentation

C6H12O6 → 2CH3 –CHOH–COOH;

• alcoholic fermentation

С6H12O6 → 2СH3 –CH2OH + 2CO2↑.

Symptoms of glucose deficiency

If there is a lack of a substance in the body, serious problems with its functioning may begin. A lack of a substance can be determined by the following symptoms:

• dizziness;
• lethargy;
• headache;
• pallor;
• cardiopalmus.

Hypoglycemia can occur as a result of diabetes mellitus or is an independent pathology. If a person begins to feel dizzy or has confused thinking, then you need to eat, for example, white bread or a sweet roll. This leads to an increase in glucose levels and cope with the symptoms that appear.

On a note! With a constant shortage of the substance, serious harm to a person occurs. You need to see a doctor who will prescribe an appropriate examination.

Obtaining glucose

Artificial acquisition

The most studied method of producing glucose chemically is the process of decomposition of di- and polysaccharides. The reagents used are starch or cellulose and water, which decompose to form glucose and by-products.

• Starch hydrolysis

(C6H10O5)n + nH2O t,H+→ nC6H12O6

• From formaldehyde

6HCOHCa(OH)2→C6H12O6

• hydrolysis of disaccharides

C12H22O11 + H2Ot,H+→ 2C6H12O6

Natural Receipt

Glucogenesis is a separate term for the process of formation of glucose from molecules of keto acids, for example, pyruvic acid. Gluconeogenesis is the formation of glucose from lactate, pyruvate and other non-carbohydrate compounds.

What are the dangers of high blood glucose levels?

Elevated glucose levels can be caused by several reasons:

• lack of physical activity;
• somatic diseases;
• stress, depression;
• heavy food;
• non-compliance with medication regimen for diabetes mellitus.

Excess sugar can cause extra pounds, diabetes and other pathologies. In such conditions, it is necessary to adhere to a special diet that will lower blood sugar.

Important tests

What additional studies need to be performed to diagnose diabetes mellitus?

Equally important is the determination of C-peptide. Insulin and C-peptide are the end products of proinsulin conversion in the beta cells of the pancreatic islets. Determination of C-peptide provides control over the functioning of pancreatic beta cells and insulin production. Diagnostically significant is that it is the C-peptide that allows one to assess the level of insulin and more clearly select the required (missing) dose of insulin. If the C-peptide in the blood decreases, this indicates a lack of insulin produced by special cells of the pancreas. Normally, the level of C-peptide is 0.5 - 2.0 μg/l. Currently, much attention is paid to the determination of antibodies to beta cells of the islets of Langerhans, the presence of which leads to the destruction of the cells themselves and disruption of insulin synthesis, which results in the appearance of type 1 diabetes. Autoimmune mechanisms of cell destruction can be hereditary in nature, as well as can be triggered by a number of external factors, such as viral infections, various forms of stress and exposure to toxic substances. Thus, the determination of antibodies to beta cells can be used for early diagnosis and identification of predisposition to type 1 diabetes. Patients with autoantibodies experience a progressive decline in beta cell function and insulin secretion. Antibodies to insulin are found in 35-40% of patients with newly diagnosed type 1 diabetes. Antibodies to insulin can be observed in the stage of prediabetes. An antigen has also been found that represents the main target for autoantibodies associated with the development of insulin-dependent diabetes. This antigen turned out to be glutamic acid decarboxylase (gad), a very informative marker for diagnosing prediabetes. Antibodies to GAD can be detected in a patient 5-7 years before the clinical manifestation of the disease. The following is important: the determination of these markers allows in 97% of cases to differentiate type 1 diabetes from type 2, when the clinical picture of type 1 diabetes is disguised as type 2. And finally, the signal marker of body weight is leptin, which is formed in fat cells. It signals the brain to stop eating and increase energy expenditure. However, this mechanism is disrupted with large excess weight. These people have too many fat cells that secrete leptin, and its levels increase significantly with every extra gram of weight. When there is too much leptin in the blood, it stops playing its signaling function. Always remember that timely diagnosis will allow you to avoid health problems. The clinical and biochemical laboratory of MK CELT performs a wide range of tests, and the modern level of equipment, the qualifications of specialists and the timing of research guarantee high quality and reliability.

How to take glucose tablets

Medicines containing glucose are prescribed for the following conditions:

• poisoning;
• lack of carbohydrates supplied with food;
• dehydration caused by vomiting and indigestion;
• lack of substance in the body.

For diabetes

Medicines are generally not prescribed for diabetes. But there are exceptions when it is urgently necessary to increase the content of an element. Hypoglycemia occurs when there is excessive inulin content.

Medicines can be taken in the form of solutions or tablets. For diabetes mellitus, tablets are the appropriate form according to doctors. The solution should be taken in critical situations.

Application

Glucose is the main nutrient of autotrophic and heterotrophic organisms, which absorb it and convert it into organic substances necessary for life. Cellular respiration of organisms begins with the process of glycolysis - the breakdown of glucose into pyruvic acid. Salts are formed from the products of glycolysis - pyruvates, and further reactions lead to the formation of adenosine triphosphate, or the energy molecules ATP. As a storage compound, organisms store reserve energy-producing substances glycogen (in heterotrophs) and starch (in autotrophs).

Glucose is a low molecular weight sweetener in the food industry and an additional substance in pharmaceuticals. The sweetener sorbitol (E420) is obtained by hydrogenating glucose until a hydroxo group is formed in place of the aldehyde.

In medicine, glucose solution is used for intravenous injection to counteract food, alcohol and other intoxications. In the field of endocrinology, it is used to diagnose diabetes as a test indicator.