What is hemoglobin in the blood and what is it responsible for? Critical level of hemoglobin in the blood - how dangerous are deviations from the norm? Hemoglobin performs

What is hemoglobin? is a complex blood protein. It is found in red blood cells and is formed from iron and protein. Hence its name. In translation, iron is “heme”, and protein is “globin”. It is thanks to the iron ion that blood acquires its color. There is an opinion that the brighter and more saturated the color of the blood, the better the hemoglobin level in the blood. It transports oxygen from the lungs to the rest of the cells in the body, and also performs the function of removing carbon dioxide from the tissues to the lungs. The greater the amount of hemoglobin, the better cages The body receives oxygen and works faster.

When there is not enough hemoglobin, the transport of oxygen throughout the body deteriorates. Then the metabolism in the cells is disrupted and their functions deteriorate.

Hemoglobin norm

Checking indicators is an important stage in diagnosing the condition of the body. As a result of a blood test alone, no diagnosis can be made, but timely determination of the amount of hemoglobin in the blood can indicate obvious disturbances in body functions and the need for treatment.

Norm for men and women different ages is different. The other is for pregnant women. For girls and boys under the age of 12, the norm is the same. We present below the hemoglobin norm scale for infants, children, women and men of different ages.

In infants:

• newborns - from 135-140.

Normal level in children:

• from one month: from 100-200;
• from one to two months: from 100-180;
• from two to six months: from 105-140;
• from six months to two years: from 105-135;
• from two to six years: from 115-135;
• from six to twelve years: from 115-155.

Among women:

• from twelve to eighteen years: from 120-160;
• from eighteen to sixty years: from 120-150;
• after sixty years: from 117-138.

In pregnant women:

• in pregnant women, the norm can drop to 110.

For men:

• from twelve to eighteen years: from 130-160;
• from eighteen to sixty years: from 136-177;
• after sixty years: from 124-149.

Low hemoglobin

This condition is called anemia (anemia). It is characterized by a sharp decrease in full-fledged red blood cells. If hemoglobin is low, cells and tissues begin to suffer from a lack of oxygen.

Causes

• Significant blood loss. Among them there are obvious and hidden. Obvious blood losses include menstruation, bleeding during hemorrhoids, and blood loss during injuries or operations. Hidden blood loss can occur during gastrointestinal diseases.
• Lack of vitamins C and B12.
• Transferred infectious diseases or autoimmune. Such diseases damage red blood cells, shortening their lifespan. Dysentery, salmonellosis, hepatitis, pneumonia, pyelonephritis, tuberculosis - all these diseases damage red blood cells.
• Helminths. They suck great amount B12, responsible for the absorption of iron.
• Unbalanced diet. The diet does not contain foods containing folic acid, protein, or B vitamins.
• Carrying a child and feeding. During these periods, a woman’s body consumes too much iron.
• Iron is not absorbed. This happens with gastritis, when the gastric mucosa becomes thinner, during dysbacteriosis, after undergoing surgical interventions in the gastrointestinal tract.
• Poor quality blood diseases.
• Gastrointestinal cancer.
• Blood pathologies.
• Bone marrow diseases.
• Chemotherapy sessions.
• Kidney failure.
• Stress.
• Diets.
• Liver disorders.

Symptoms

You can find out about low hemoglobin not only from a blood test. Almost always this is due to iron deficiency.

Some symptoms may indicate low hemoglobin:

• low pressure;
• lack of energy, lethargy;
• accelerated heartbeat;
• headache;
• brittle nails, spotting, lamination;
• hair loss;
• skin becomes dry;
• strange taste preferences (for example, most often such people like the smells of gasoline, paint, varnish, solvent);
• the skin becomes pale;
• changes in the color of the tongue - it becomes reddish and painful in appearance;
• slight increase in body temperature.

Treatment

Treatment always depends on the causes of deviations. If the disorder is caused by gastritis, you need to treat it; if the cause is bleeding, solve this problem.

In addition to local treatment, you are prescribed to take an iron supplement, which can only be prescribed by a doctor. Iron supplements are prescribed in moderate dosage, since an increased dose can cause the opposite effect - intolerance to the body. Daily norm The average iron intake for an adult is 300 mg. At the beginning of treatment, doctors give maximum dosage, then after normalizing the hemoglobin level, the dose of the drug is reduced by two or three times.

When the level returns to normal, treatment should be continued for another two or four months.

After completing the course of treatment, you should definitely do prophylaxis two or three times a year. At this stage, you are prescribed to take about 40-60 mg of iron per day. An increase in hemoglobin will be observed only a month after taking the medication.

When low hemoglobin is associated with a lack of vitamin B12, vitamin injections are prescribed at a dosage of 300-500 mcg per day. When hemoglobin normalizes, which often happens in the fourth or sixth week, the dosage is reduced, and treatment with the drug also continues for about two or three months.

A special diet will help increase your level. List of foods that increase hemoglobin:

• meat products
• liver
• languages
• beef meat
• egg yolks
• buckwheat
• peas
• lentils
• tomatoes
• all types of onions
• pumpkins
• potato
• apple
• grenades
• pears
• apricots
• black currant berries
• cranberries
• nuts
• all types of dried fruits
• dried mushrooms
• salmon caviar
• dark chocolate
• green tea (promotes iron absorption)

Video: Low hemoglobin - School of Dr. Komarovsky

Increased hemoglobin

Too high a level indicates an excess of red blood cells. There is such a diagnosis - erythrocytosis. This disrupts blood circulation, its clotting and leads to poor health.

Natural causes

An increase in hemoglobin will be normal for people living in the mountains, where the air contains less oxygen. Then the excess cannot be called a deviation. This is how the body adapts to the external environment.

Hemoglobin may naturally increase in athletes. Their body needs oxygen more and therefore the body reacts in this way to constant physical activity.

Pathological causes

An increase in the norm of red blood cells in a person or an increase in their size is the main reason for excess hemoglobin in the body. In addition, it may increase in the following cases:

• congenital heart disease;
• pulmonary fibrosis;
• heart and vascular failure;
• intestinal obstruction;
• cancer diseases.

Symptoms

• thick blood;
• high pressure;
• skin redness;
• sleep disturbance;
• weakness, fatigue.

Treatment

Treat increased hemoglobin This can be achieved through diet, limiting the consumption of animal protein. They contain iron, which is easily absorbed. By changing your diet, choosing foods with less iron, hemoglobin can be brought back to normal.

For treatment, medications are prescribed that help thin the blood.

Erythrophoresis helps in the treatment of high hemoglobin. This procedure reduces the number of red blood cells and lowers hemoglobin.

In treatment, it is important to take into account the cause of the disease and treat it first. Diet may lower the level, but will not eliminate the problem permanently.

Normal hemoglobin levels are very important for the normal functioning of the body. Try to eat healthy and balanced to keep its levels normal. We hope that our article will help you maintain your health and well-being in the future. long years. We wish good health you and your loved ones!

Hemoglobin is an extremely important part (protein) of red blood cells that carries oxygen molecules to all parts of the body. Low and high levels of this protein can negatively affect our health. In this article, we will look at the symptoms of high or low hemoglobin, as well as the health factors or types of diseases that increase or decrease the level of hemoglobin in our blood.

This is the second article in a series of articles on hemoglobin

1. Hemoglobin: reasons for low or high levels

The article is based on the findings of 37 scientific studies

The article quotes the following research authors:

• Department of Medicine, Milan, Italy
• University Hospital Miguel Served, Zaragoza, Spain
• Rush Alzheimer's Center, Chicago, USA
• Department sports medicine, University of Bayreuth, Bayreuth, Germany
• Center for Hematology and Oncology, Munich, Germany
• Department of Hematology, City Hospital Nottingham, UK
• and other authors.

Please note that the numbers in brackets (1, 2, 3, etc.) are clickable links to the reviewed Scientific research. You can follow these links and read the original source of information for the article.

Low hemoglobin level

Having a slightly low hemoglobin (Hb) level is usually not accompanied by symptoms. However, any decrease in hemoglobin or red blood cell (RBC) count results in decreased exercise endurance, even when hemoglobin levels are in the 12-13 g/dL range.

A deficiency of hemoglobin and/or red blood cells is called anemia.

According to the World Health Organization (WHO), anemia is defined by a hemoglobin level of less than 12 g/dl in women and less than 13 g/dl in men .

Although the ability of body tissues to obtain oxygen remains proportional to the level of circulating hemoglobin in the blood, in people with chronic anemia a compensatory mechanism develops to improve oxygen delivery to body tissues. This mechanism maintains a sufficient volume of oxygen for the functioning of organs until hemoglobin decreases to 7-8 g/dl.

Severe anemia is defined as hemoglobin levels below 7 g/dL .

Symptoms of low hemoglobin

Signs of low hemoglobin (anemia) include: [,]

• Fatigue and general weakness
• Irritability
• Dizziness
• Headache
• Poor concentration
• Shortness of breath on exertion
• Cardiopalmus
• Rapid onset of fatigue with low physical activity
• Cold hands and feet (impaired ability to maintain body temperature)

It is often not easy to tell if you are anemic. But people with low hemoglobin exhibit several designated symptoms at the same time. In addition, they often become accustomed to their symptoms and consider them normal.

High hemoglobin level

You are considered to have high hemoglobin if your hemoglobin level is greater than 16 g/dL (women) or 18 g/dL (men) [,]. This condition is called polycythemia.

Higher hemoglobin levels increase blood viscosity. The relationship between the increase in hemoglobin value and viscosity is linear up to 16 g/dl. Above this level the relationship becomes exponential - a small increase in hemoglobin leads to strong increase blood viscosity.

As soon as the hemoglobin concentration reaches values ​​above 18 g/dl, the viscosity of the blood reaches such a level that it impairs blood circulation in the small blood vessels, and the delivery of oxygen to the organs and tissues of the body decreases sharply.

This condition often manifests as a bluish discoloration of the skin and impaired mental function as a result of cerebrovascular accident. And all these signs are very similar to the course of severe anemia. In addition, due to poor blood circulation, the risk of blood clots increases significantly.

A study of people with chronic mountain sickness demonstrated that, due to the combination of high altitude and poor lung function, long-term survival with hemoglobin levels above 20 g/dL is not possible.

Increased hemoglobin has several causes, but is usually the result of these 2 mechanisms

• Increased production of blood cells. This occurs as compensation when the oxygen throughput in the blood is disrupted.
• Decreased plasma volume (the liquid part of the blood).

Symptoms of elevated hemoglobin

Signs of high hemoglobin include[,]:

• High blood pressure
• Itchy skin
• Headache
• Dizziness
• Ruddy complexion
• Blurred vision
• Burning, tingling, or stabbing sensations and numbness in the extremities.

Factors that increase hemoglobin

Height

Living at a higher altitude increases hemoglobin levels. This is due to the fact that low level Oxygen at high altitudes increases blood cell production. As a result, the amount of hemoglobin increases along with the cells in order to deliver more oxygen to the body tissues. [ , ]

For example, studies have shown that in healthy men and women, hemoglobin increased within 7 days of ascending to an altitude of 5,260 meters, but returned to normal levels within the same 7 days of descending to an altitude of 1,525 meters (the study included 21 volunteer).

Athletes often use high altitude to increase their hemoglobin levels and improve athletic performance. Increasing hemoglobin through exercise high altitude is considered legal manipulation in various endurance sports, in contrast to the illegal use of erythropoietin (EPO), androgens (more on these below), and autologous blood transfusions.

The increase in hemoglobin contributes to increased endurance, which is proportional to the increase in the oxygen capacity of the blood.

Long-term living at altitudes between 2,100 and 2,500 meters increases hemoglobin levels and studies show that this effect persists for 2-3 weeks after descending to sea level.

High hemoglobin is also a sign chronic mountain sickness.

Residents of the Himalayas, but not residents of the Andes Mountains ( South America) were able to adapt to high altitude by reducing the level of hemoglobin in their body. Because of this, they rarely suffer from chronic mountain sickness. These differences in adaptation are due to the very long time that the inhabitants of the Himalayas were forced to adapt to higher altitudes. At high altitude, the inhabitants of the Andes mountains have been inhabited for 9,000 to 12,000 years, but the Himalayan plateau was filled with people more than 50,000 years ago.

Residents of Tibet (the high-altitude part of it) by lowering hemoglobin levels were able to increase their physical endurance and reduce the risk of blood clots, chronic mountain sickness, pre-eclampsia during pregnancy, and reduce infant mortality rates (study involving 1,749 women). [ , ]

Smoking

Carbon monoxide (CO) in tobacco smoke competes with oxygen to bind to hemoglobin, and CO is 210 times more efficient at this bond than oxygen.. To compensate for the “loss” of part of the hemoglobin bound by carbon monoxide, the body begins to produce red blood cells, which contribute to the growth of hemoglobin. This condition is often called smoker's polycythemia.

Respiratory and cardiovascular diseases

Lung diseases and cardiovascular diseases, which contribute to a decrease in the amount of oxygen in the blood and also stimulate an increase in hemoglobin levels.

In addition to smoking, increased hemoglobin also appears as the body's response to conditions of low oxygen in the blood. Such conditions include chronic obstructive disease lungs (COPD) or sleep apnea.

Polycythemia vera

Polycythemia vera is a bone marrow disease in which there is an overproduction of red blood cells (and high hemoglobin as a result).

Today there is no specific treatment for this disease. However, it is possible to treat symptoms and increase life expectancy.

In women with increased level hemoglobin more than 16 g/dl or in men more than 18 g/dl, polycythemia vera can be suspected. It is more common in older people.

People with polycythemia vera may not have any symptoms. However, sometimes, they may experience an itching sensation after taking a warm bath, weakness, weight loss, development of gouty arthritis and peptic ulcers. In many cases, this condition is caused by a mutation in the JAK2 gene.

Due to a gene mutation, the disease is often hereditary; children of the first degree have a 5-7 times higher risk of developing polycythemia vera compared to the general population. Additionally, high incidence rates of polycythemia vera are common among descendants of Ashkenazi Jews.

Long-term risks of this disease include progression to acute leukemia or severe bone marrow damage.

Dehydration

A decrease in plasma volumes (the liquid part of the blood) contributes to an increase in the relative values ​​of hemoglobin. .

Any condition that results in fluid loss, such as dehydration or severe burns, results in relatively high hemoglobin levels.

Severe dehydration can raise hemoglobin concentrations by 10-15%.

In a short period of time, there is a transient increase in hemoglobin levels, the values ​​of which are restored over the next 24 hours.

The increase in hemoglobin during physical activity is associated with a decrease in the volume of fluid in plasma (the liquid part of the blood), the replenishment of which does not occur intensively enough during exercise.

Regular exercise, on the other hand, reduces hemoglobin levels by increasing blood volume.

Erythropoietin

Testosterone and other hormones

Testosterone stimulates the production of red blood cells and increases hemoglobin levels, especially if there is a lot of testosterone or it comes from outside in high doses.

Androgens ( male hormones) stimulate the production of blood cells. They do this by increasing the production of erythropoietin, which stimulates bone marrow function and increasing the amount of iron incorporated into red blood cells. .

Other hormones that increase red blood cell production include cortisol, a growth hormone And insulin-like growth factor.

Kidney disease

Wilms tumor, other types of kidney cancer, and polycystic kidney disease - increase the number of red blood cells and hemoglobin.

A kidney transplant can work in a similar way. The study found that 10 of 59 kidney transplant patients who survived more than 3 months after surgery had high hemoglobin.

Factors that reduce hemoglobin

Iron deficiency

Red blood cells require large amounts of iron to produce hemoglobin. Actually, More than half of all iron in the body is contained in hemoglobin.

Iron deficiency lowers hemoglobin levels and leads to anemia when the body's iron stores are depleted.

In the absence of major bleeding, Iron deficiency anemia usually develops slowly over months or years.

Establishing a diagnosis of iron deficiency anemia can be similarly time-consuming, especially if the amount of iron in the diet helps maintain hemoglobin in the normal range.

In developed countries, 4-20% of the population suffers from iron deficiency anemia, while in developing countries oh these numbers range from 30-48%.

Deficiency of minerals and vitamins

In addition to iron deficiency, anemia can develop when there is a decrease in the intake of other vitamins and minerals, such as vitamin A, vitamin B9 (folic acid), vitamin B12, selenium, zinc, or copper. All of these vitamins and minerals are important for the production of blood cells.

Vitamin A deficiency

Vitamin A deficiency can lead to anemia because this substance is important for the production of blood cells and the binding of iron. [ , ]

Vitamin A increases erythropoietin production(EPO), a stimulant of red blood cell production. Vitamin A deficiency is common in developing countries but rare in developed countries.

The study found that children aged 6 to 59 months after birth who received a high dose of vitamin A showed increased-normal hemoglobin levels and had a reduced risk of developing anemia (study of 2,397 Ethiopian children).

Another study found that in Moroccan schoolchildren, vitamin A supplementation increased hemoglobin by an average of 0.7 g/dL and reduced the prevalence of anemia from 54% to 38% (81 schoolchildren in the study).

Mothers with vitamin A deficiency exhibit lower hemoglobin and a higher incidence of anemia. They also give birth to babies with lower hemoglobin levels (200 Egyptian mothers took part in the study).

Folic acid (vitamin B9) levels

Shortage folic acid(vitamin B9) is another major cause of anemia.

Folate deficiency anemia occurs due to poor nutrition, impaired intestinal absorption, increased need for this vitamin (for example, during pregnancy), when taking certain medications, or when hereditary diseases. [ , ]

Vitamin B12 and pernicious anemia

Lack of vitamin B12 (cobalamin) leads to anemia. It is usually caused by malabsorption in the intestines of people in developed countries due to their unhealthy diets, and insufficient dietary intake in people of developing countries.

Vitamin B12 deficiency occurs in 6% of people aged 60 years and older, while minor (mild) deficiency occurs in almost 20% of people in their lifetime.

Decreased absorption of vitamin B12 is often associated with diseases - pernicious anemia, autoimmune gastritis(inflammation of the stomach that prevents the absorption of vitamin B12). Prevalence pernicious anemia V European countries makes up about 4% of the population, and is more common in older people.

Vitamin D increases hemoglobin levels

Research shows vitamin D deficiency increases risk of anemia(findings of a meta-analysis from 7 studies involving 5,183 adults).

Vitamin E helps increase hemoglobin

Vitamin E supplementation improved hemoglobin levels in mildly anemic healthy adults (study of 86 and 60 patients).

Zinc is important for maintaining iron levels

Zinc is necessary for the proper functioning of several enzymes that play a role in the production of iron from foods. That is why Zinc deficiency can lead to anemia.

The study found that patients with low zinc levels were more likely to have symptoms of anemia (86 study participants).

Copper promotes blood cell production

Copper deficiency causes disturbances in the production of blood cells and copper-deficiency anemia.

Too much tea

Green tea leaves naturally contain high levels of polyphenols, tannins, and aluminum. Both polyphenols and aluminum reduce iron levels and have been shown in a study to reduce hemoglobin levels in animals.

Tea interferes with the absorption of iron and can lead to iron deficiency anemia if consumed in very large quantities. However, this only happens if you consume excessive amounts of tea.

There is not a single case where a person developed anemia after daily intake of more than 1.5 liters of green tea (4 or more teaspoons of dry tea) for over 20 years.

Trained athletes, particularly in endurance sports, often have “sports anemia.”

This is not anemia in the clinical sense. In fact, athletes have increased total cell mass and hemoglobin levels in the blood compared to non-athletes. However, the relative decrease in hemoglobin is caused by an increase in the volume of plasma (the liquid part of the blood) in their blood.

Exercise also causes the destruction of old red blood cells in working muscles or during compression, such as in the soles of the feet during running.

The study found that decreases in hemoglobin were more common in people who trained for endurance compared to strength training or mixed training (endurance + strength) (747 athletes and 104 untrained adults participated).

Pregnancy

During a normal pregnancy, blood volume increases by an average of 50%. This rapid addition of blood volume begins in the first trimester. However, plasma volume (the liquid part of the blood) increases more than the mass of red blood cells, which leads to a relative decrease in hemoglobin levels in the first half of pregnancy. This condition is known as anemia of pregnancy.

This relative decrease in hemoglobin is most pronounced in women with a large fetus or in those who are planning twins.

It is important to note that although hemoglobin decreases, another value called mean erythrocyte volume (MCV), also obtained from a clinical blood test, does not change significantly during pregnancy.

Thus, a hemoglobin level below 9.5 g/dL in combination with an MCV (mean erythrocyte volume) value below 84 femtoliters (fl) is used to indicate true anemia (iron deficiency) in pregnancy. .

Bleeding

Blood loss can occur as a result of wounds and ruptured abscesses, heavy menstrual bleeding, or frequent blood donations (donation).

Women with heavy menstrual bleeding have lower hemoglobin levels and are more likely to have anemia (pilot clinical trial with the participation of 44 women).

Nonsteroidal anti-inflammatory drugs (NSAIDs) are known to cause disruption of the intestinal integrity and bleeding in the upper part of the intestine. In addition, low doses acetylsalicylic acid(aspirin, a drug from the NSAID group) increase blood loss, and frequent use aspirin can lead to anemia.

People who donate blood too frequently may also develop iron deficiency anemia. This is because blood donation removes large amounts of iron from the blood. It has been found that even a 56-day interval between donating blood as a donor is not sufficient to restore normal hemoglobin and iron values.

Monitoring your iron levels by measuring ferritin in your blood may also be helpful.

Medicines to lower blood pressure

Medicines used to lower blood pressure may also reduce hemoglobin levels. Usually these changes are small. However, in some cases, these drugs cause clinical significant degrees anemia.

Antihypertensive drugs blood pressure cause blood thinning (increased fluid content in the blood), hemolytic anemia(pathological destruction of red blood cells), and/or suppression of red blood cell production.

This most often occurs with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers.

Increased weight (obesity)

A study of 707 teenagers found that it was associated with lower hemoglobin levels in girls.

Hypothyroidism

Anemia often accompanies illness thyroid gland.

Thyroid hormones stimulate the production of red blood cells, both directly and by increasing the production of erythropoietin (EPO).

Adding iron to standard treatment thyroxine (one of two iodine-containing thyroid hormones) improves hypothyroidism better than thyroxine alone (study of 60 patients). [ , ]

This relationship between anemia and thyroid disease goes both ways, as decreased activity of the thyroid gland leads to anemia, and iron deficiency anemia reduces the level of thyroid hormones. .

Pregnant women with iron deficiency anemia are more likely to have hypothyroidism or subclinical hypothyroidism (study of 2,581 participants).

Chronic inflammatory diseases

Anemia of inflammation(also called anemia of chronic disease) – This commonly diagnosed anemia is associated with a worse prognosis and increased mortality in some diseases. [ , ]

This anemia of inflammation occurs when obesity, aging, kidney failure, cancer, chronic infections and autoimmune diseases.

This is mild to moderate anemia. Hemoglobin rarely decreases below 8 g/dL.

This state of the body is caused by immune activation (interleukin IL-6 increases the level of the hormone hepcidin, which reduces the amount of iron in the blood). [ , ]

Best treatment Anemia of this type is treatment of the underlying disease. When this is not possible, blood transfusions, intravenous iron, and medicines, which stimulate the production of red blood cells, which may improve the condition.

This type of anemia can be treated by activating AMPK, an AMP-activated protein kinase.

Rheumatoid arthritis

Anemia is one of the symptoms of rheumatoid arthritis. It is estimated that 30-60% of patients with rheumatoid arthritis suffer from anemia .

Additionally, people with high disease activity have lower hemoglobin levels (study of 89 patients).

Inflammatory bowel diseases

Anemia is one of the most common complications of IBD (). [ , ] This affects the quality of life and ability to work, and also increases the frequency of hospitalizations of patients.

The prevalence of anemia in IBD is variable and ranges from 6-74%, depending on the study.

Gluten intolerance (celiac disease)

Celiac disease affects about 1% of the population. Anemia is the most common symptom of celiac disease, affecting 32-69% of adults with gluten intolerance. Conversely, among patients with unexplained iron deficiency anemia, 5% of them are confirmed to have celiac disease.

Anemia in celiac disease is characterized by impaired absorption of iron and loss of blood due to damage to the intestinal walls. Even after starting a gluten-free diet, it takes 6 to 12 months for most patients to recover from anemia.

In particular, half of the patients with celiac disease still had iron deficiency anemia and low hemoglobin even after one to two years on a gluten-free diet. .

Patients with celiac disease often benefit from intravenous administration iron preparations.

The mechanism of development of anemia in chronic kidney disease (https://jasn.asnjournals.org/content/23/10/1631)

Chronic kidney disease

Anemia also often develops as a complication of chronic kidney disease(CKD). The severity of anemia is proportional to the degree of kidney dysfunction.

Kidney damage results in the inability to produce the required amount of erythropoietin (EPO), a kidney hormone, and erythropoietin is known to stimulate the production of blood cells. Therefore, hemodialysis patients receive substances that stimulate the production of red blood cells along with iron, which helps increase hemoglobin levels.

The FDA recommends 10-12 g/dL as a hemoglobin level goal in patients with (CKD). Higher hemoglobin values ​​(>13 g/dL) should be avoided as these hemoglobin values ​​have been shown to be associated with poor clinical outcome in CKD.

Liver diseases

Among patients with chronic diseases More than 75% of livers show signs of anemia. It is mainly associated with acute or chronic intestinal bleeding which leads to iron deficiency anemia.

(NAFLD) is one of the most common liver diseases worldwide, and one third of adults with NAFLD are iron deficient. [R ].

Also, some medications used to treat anemia can cause liver disease. For example, anemia is often associated with pegylated interferon alfa-2a and ribavirin, which are used in the treatment chronic virus hepatitis C.

Helicobacter infection (H. pylori)

Anemia often accompanies infection helicobacter(H. pylori). More than 50% of patients with unexplained iron deficiency anemia may have an active infectionhelicobacter (H. pylori).

Bacterium H. pylori increases iron loss due to:

• Bleeding caused by inflammation of the stomach peptic ulcer or stomach cancer.
• Reduced absorption of the gland, which also occurs due to inflammation of the stomach.
• Decreased vitamin C levels (vitamin C usually helps with iron absorption).
• Iron loss caused by iron uptake by bacteria helicobacter. [ , ]

Most sick people with H. pylori-associated anemia completely recovered from anemia only after successful anti-bacterial treatment. (study of 84 patients).

Lead poisoning

Lead poisoning impairs hemoglobin production and reduces the survival of red blood cells. .

Higher blood lead concentrations were associated with anemia in 60 children who were exposed to lead from contaminated drinking water.

Finally, factory workers with chronic low-level lead exposure had a higher risk of developing anemia (533 men and 218 women in the study).

Cadmium poisoning

Cadmium causes anemia due to the destruction of red blood cells, iron deficiency and decreased production of erythropoietin (EPO).

Anemia and low erythropoietin levels are clinical signs itai-itai disease, which is a condition caused by long-term cadmium intoxication in Japan.

Aflatoxin

Pregnant women with high level Aflatoxin B1 levels in the blood greatly increased their chances of developing anemia (study of 755 women).

Congenital sideroblastic anemia

This is a genetic disorder that prevents the formation of red blood cells, leading to hemoglobin deficiency.

Some patients require regular blood transfusions, while others require sporadic blood transfusions at times when there is suppression of activity in their bone marrow, e.g. viral infection.

In some cases, the condition of congenital sideroblastic anemia improves by taking vitamin B6.

Sickle cell anemia

Sickle cell anemia causes inflammation, blood clots, destruction of red blood cells, and oxygen deficiency, which ultimately leads to damage to the body's organs. Occasional exacerbation of the disease causes severe pain, attacks of pulmonary failure and cases of stroke.

About 240,000 children are born each year with sickle cell disease, most of whom live in Africa. Only 20% of these children survive to their second birthday. The median survival rate for patients with sickle cell disease in the United States is about 42 years.

There is an important reason why this disease is so common in Africa. Namely, people who have an abnormal copy of hemoglobin S are resistant to malaria [,].

Carriers of one copy of the hemoglobin S gene usually have 40% hemoglobin S in their blood and 56-58% normal hemoglobin. They typically live without symptoms and require severe oxygen deprivation for sickle cell disease symptoms to occur.

Approximately 8% of African Americans carry this altered hemoglobin variant. Hydroxyurea has been approved for the treatment of adult patients with sickle cell disease.

Thalassemia

Thalassemia is a disorder resulting from a combination of more than 300 known mutations in the beta chain or a smaller number of mutations in the alpha chain of hemoglobin. These mutations are common in the Mediterranean, Southeast Asia and China. About 60,000 children are born each year with this disease.

People with thalassemia have varying degrees anemia. In more severe cases, such as beta thalassemia, there is an inability to maintain hemoglobin levels greater than 6.5 g/dL.

The disease is treated with transfusion, bone marrow transplantation, or gene therapy. Like sickle cell hemoglobin S carriers, thalassemia mutation carriers are also resistant to malaria. Therefore, these mutations are quite common in Africa.

Scheme of the development of iron deficiency anemia (https://blogs.nejm.org/now/index.php/iron-deficiency-anemia/2015/05/08/)

Cancer

Anemia is a common symptom of cancer. It is diagnosed in 50% of cases of various oncological diseases.

There are several causes of cancerous anemia:

• Internal bleeding
• Increased destruction of red blood cells
• Lack of nutrition
• Bone marrow damage
• Radiation therapy and chemotherapy
• Erythropoietin deficiency (EPO)
• Inflammation [ , ]

Three years after cancer diagnosis, patients with advanced anemia have twice the risk of mortality compared to patients without anemia.

Low hemoglobin levels tend to be most common in people with advanced stage cancer(study of 888 patients).

HIV infection and anti-HIV drugs

Anemia is an important factor in the treatment of HIV-infected patients. It is estimated to be common in 10% of people with HIV and asymptomatic in 92% of AIDS patients.

A large study of 32,867 HIV-infected adults and adolescents in the US found that the risk of death was 170% greater in those who showed persistent anemia compared with those whose anemia was compensated.

Malaria

Malaria threatens almost half the world's population. This important factor, but not entirely clear as the cause of anemia.

Young children have high risk development severe forms anemia associated with malaria, especially in countries where there is transmission of malaria to children at birth and frequent relapses.

This type of anemia can be effectively treated with early and effective antimalarial therapy.

Enlarged spleen

People with an enlarged spleen may develop anemia due to increased destruction of red blood cells in the spleen.

An enlarged spleen can be caused by infections, liver disease, cancer, or inflammatory diseases.

Autoimmune anemia

Autoimmune anemias are caused by increased destruction of red blood cells, which are attacked by autoantibodies. This is a rare condition that accompanies a number of diseases.

Aging

People are more likely to develop anemia as they get older. Anemia was found in 11% of men and 10% of women over age 65, and in 26% of men and 20% of women over age 85 (NHANES III, 39,695 people).

A decrease in hemoglobin levels occurs in the eighth decade of life and appears to be part of the. However, anemia in older adults is associated with a range of adverse outcomes, including functional dependence, dementia, falls, heart disease, and death. .

In approximately 50% of cases, anemia in older people has reversible causes (can be corrected), including lack of iron and vitamin B12, as well as chronic renal failure.

Factors that interfere with hemoglobin function

Methemoglobin

In healthy people, methemoglobin (metHb) accounts for 1 to 2% of total hemoglobin. Some drugs and toxins are known to increase methemoglobin levels.

Carbon monoxide (carbon monoxide)

Carbon monoxide (CO) binds to hemoglobin 210 times more than oxygen. Inhalation of large amounts of carbon monoxide (carbon monoxide) leads to toxic poisoning. .

When carbon monoxide binds hemoglobin, it is not possible to further bind oxygen. This causes tissue damage due to oxygen deficiency.

When carbon monoxide binds 20% of hemoglobin, signs of brain damage and heart damage develop. . When 40-60% of hemoglobin binds, a person enters unconsciousness, coma may develop and death may occur.

Carbon monoxide poisoning is treated by oxygenating the blood or giving a blood transfusion.

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Hemoglobin- a molecule consisting of globin protein (2a- and 2β-chains) and 4 pigment groups (heme), which are capable of reversibly binding molecular oxygen. One red blood cell contains on average 400 million hemoglobin molecules. Hemoglobin bound to oxygen is called oxyheluglobin(gives the blood a bright scarlet color). The process of its binding with oxygen is called oxygenation, and its return to oke and hemoglobin - deoxygenation. Hemoglobin not bound to oxygen is called deoxyheluglobin. Hemoglobin is able to bind with carbon dioxide (carbaminghemoglobin) and carbon monoxide (carboxyhemoglobin). In addition, NO, interacting with this protein, forms various NO forms: methemoglobin, nitrosylhemoglobin(HbFe 2+ NO) and S-nitrosohemoglobin(SNO-Hb), which play the role of a kind of allosteric regulator of the functional activity of hemoglobin.

Norm and functions of hemoglobin

The amount of hemoglobin in men is 130-160 g/l, in women - 120-140 g/l. The transport of oxygen and carbon dioxide is the function of hemoglobin. Hemoglobin is a complex chemical compound consisting of globin protein and four heme molecules.

Rice. Normal hemoglobin levels in men and women

The main functions are due to the presence in their composition of a special chromoprotein protein - hemoglobin. The molecular weight of human hemoglobin is 68,800. Hemoglobin is a respiratory enzyme that is found in red blood cells and not in plasma because:

• provides a decrease in blood viscosity (dissolving the same amount of hemoglobin in plasma would increase blood viscosity several times and impede the work of the heart and blood circulation);
• reduces plasma oncotic pressure, preventing tissue dehydration;
• prevents the body from losing hemoglobin due to its filtration in the glomeruli of the kidneys and excretion in the urine.

The main purpose of hemoglobin- transport of oxygen and carbon dioxide. In addition, hemoglobin has buffering properties, as well as the ability to bind toxic substances.

Rice. Interaction of hemoglobin with oxygen. k is the reaction rate constant

Hemoglobin consists of a protein part (globin) and a non-protein iron part (heme). There are four heme molecules per globin molecule. Iron, which is part of heme, is able to attach and release oxygen. In this case, the valence of iron does not change, i.e. it remains divalent. Iron is part of all respiratory enzymes.

In blood healthy person hemoglobin content is 120-165 g/l (120-150 g/l for women, 130-160 g/l for men).

Normally, hemoglobin is contained in the form of three physiological compounds: reduced, oxyhemoglobin and carboxyhemoglobin. Hemoglobin, which has added oxygen, turns into oxyhemoglobin -НbО2,. This is a bright scarlet compound that determines the color arterial blood. One gram of hemoglobin is capable of attaching 1.34 ml of oxygen.

Oxyhemoglobin that has given up oxygen is called reduced hemoglobin (Hb). It is found in venous blood, which has a dark cherry color. In addition, venous blood contains a compound of hemoglobin with carbon dioxide - carbohemoglobin(HbCO 2), which transports carbon dioxide from tissues to the lungs.

Hemoglobin has the ability to form pathological compounds. One of them is carboxyhemoglobin - connection of hemoglobin with carbon monoxide (HbCO). The affinity of iron hemoglobin for carbon monoxide exceeds the affinity for oxygen, so even 0.1% carbon monoxide in the air leads to the conversion of 80% of hemoglobin into carboxyhemoglobin, which is not able to attach oxygen, which is life-threatening. Mild carbon monoxide poisoning is a reversible process. When you breathe fresh air, carbon monoxide is released. Inhalation pure oxygen increases the rate of HbCO breakdown by 20 times.

Table. Characteristics of hemoglobins

Methemoglobin(MetHb) is also a pathological compound, it is oxidized hemoglobin, in which, under the influence of strong oxidizing agents (ferracyanide, potassium permanganate, hydrogen peroxide, aniline, etc.), heme iron is converted from divalent to trivalent. When a large amount of methemoglobin accumulates in the blood, oxygen transport by tissues is disrupted and death can occur.

The myocardium contains muscle hemoglobin, called myoglobin. Its non-protein part is similar to blood hemoglobin, and the protein part - globin - has a lower molecular weight. Human myoglobin binds 14% total number oxygen in the body. This property plays important role in supplying working muscles. When muscles contract blood capillaries are compressed and blood flow decreases or stops. However, due to the presence of oxygen bound to myoglobin, the supply of oxygen to the muscle fibers is maintained for some time.

Globus - ball) - this is complex protein molecule inside red blood cells - erythrocytes (in humans and vertebrates). Hemoglobin makes up approximately 98% of the mass of all red blood cell proteins. Due to its structure, hemoglobin is involved in the transfer of oxygen from the lungs to the tissues, and carbon monoxide back.

The structure of hemoglobin
Hemoglobin consists of two globin chains of the alpha type and two chains of the other type (beta, gamma or sigma), connected to four molecules of heme, which contains iron. The structure of hemoglobin is written in the letters of the Greek alphabet: α2γ2.

Hemoglobin exchange
Hemoglobin is formed by red blood cells in the red bone marrow and circulates with the cells throughout their life - 120 days. When old cells are removed by the spleen, components of hemoglobin are removed from the body or released back into the bloodstream to be incorporated into new cells.

Types of hemoglobin
TO normal types hemoglobin includes hemoglobin A or HbA (from adult - adult), having the structure α2β2, HbA2 (minor adult hemoglobin, having the structure α2σ2 and fetal hemoglobin (HbF, α2γ2. Hemoglobin F - fetal hemoglobin. Replacement with adult hemoglobin completely occurs by 4-6 months (the level of fetal hemoglobin at this age is less than 1%). Embryonic hemoglobin is formed 2 weeks after fertilization, later, after the formation of the fetal liver, it is replaced by fetal hemoglobin.

There are more than 300 abnormal hemoglobins, they are named after the place of discovery.

Hemoglobin function

The main function of hemoglobin is to deliver oxygen from the lungs to the tissues and carbon dioxide back.

Forms of hemoglobin

• Oxyhemoglobin- combination of hemoglobin with oxygen. Oxyhemoglobin predominates in arterial blood going from the lungs to the tissues. Due to the content of oxyhemoglobin, arterial blood has a scarlet color.
• Reduced hemoglobin or deoxyhemoglobin(HbH) - hemoglobin that gives oxygen to tissues
• Carboxyhemoglobin- combination of hemoglobin with carbon dioxide. It is found in venous blood and gives it a dark cherry color.

How does this happen? Why does hemoglobin take up oxygen in the lungs and give up oxygen in the tissues?

Bohr effect

The effect was described by the Danish physiologist Christian Bohr http://en.wikipedia.org/wiki/Christian_Bohr (father of the famous physicist Niels Bohr).
Christian Bohr stated that with greater acidity (lower pH, for example in tissues), hemoglobin will bind less with oxygen, which will allow it to be released.

In the lungs, under conditions of excess oxygen, it combines with the hemoglobin of red blood cells. Red blood cells carry oxygen through the bloodstream to all organs and tissues. Oxidation reactions take place in the tissues of the body with the participation of incoming oxygen. As a result of these reactions, decomposition products are formed, including carbon dioxide. Carbon dioxide from tissues is transferred to red blood cells, due to which the affinity for oxygen decreases, oxygen is released into the tissues.

Bohr effect is of great importance for the functioning of the body. After all, if cells work intensively and release more CO2, red blood cells can supply them with more oxygen, preventing oxygen “starvation”. Therefore, these cells can continue to work at a high rate.

What is the normal hemoglobin level?

Each milliliter of blood contains about 150 mg of hemoglobin! Hemoglobin levels change with age and depend on gender. Thus, hemoglobin in newborns is significantly higher than in adults, and in men it is higher than in women.

What else affects hemoglobin levels?

Some other conditions also affect hemoglobin levels, such as exposure to altitude, smoking, and pregnancy.

Diseases associated with changes in the amount or structure of hemoglobin

• An increase in hemoglobin levels is observed with erythrocytosis and dehydration.
• A decrease in hemoglobin levels is observed in various anemias.
• In case of carbon monoxide poisoning, carbhemoglobin is formed (not to be confused with carboxyhemoglobin!), which cannot attach oxygen.
• Under the influence of certain substances, methemoglobin is formed.
• A change in the structure of hemoglobin is called hemoglobinopathy. The most famous and frequent illnesses This group includes sickle cell anemia, beta thalassemia, persistence of fetal hemoglobin. See hemoglobinopathies on the World Health Organization website http://www.who.int/mediacentre/factsheets/fs308/ru/index.html

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Hemoglobins are iron-containing blood proteins of a complex structure that are responsible for gas exchange and maintaining a stable metabolism. IN circulatory system hemoglobin acts as a kind of intermediary between tissues and lungs in the process of exchanging carbon dioxide and oxygen.

The permissible level of hemoglobin changes with age, but slight deviations in the normal values ​​are possible. Imbalance leads to development serious illnesses, and some of them are in the nature of an irreversible pathological process.

Deviation from the norm of this protein will in any case be accompanied by a corresponding clinical picture Therefore, if you have any other symptoms, you should immediately seek medical help rather than carry out treatment yourself. Define effective treatment is possible only after a blood test for hemoglobin has been performed.

Functions

The functions of hemoglobin are to ensure the respiratory process in the body, which is carried out in three stages:

• cellular respiration - cells are saturated with oxygen;
• external breathing– oxygen enters the lungs, and carbon dioxide is released by the body;
• internal respiration - in the lungs, oxygen captures hemoglobin, they are transformed into oxyhemoglobin and distributed to all cells.

That is why an imbalance of this protein can lead to extremely negative consequences, and in some cases even fatal.

Kinds

Human blood contains different types hemoglobin:

• fetal or fetal - this type of protein is found in the blood of a newborn and decreases to 1% of the total amount of hemoglobin in the body by the fifth month of a child’s life;
• oxyhemoglobin - found in arterial blood cells and associated with oxygen molecules;
• carboxyhemoglobin - found in venous blood and associated with carbon dioxide molecules, with which it is transported to the lungs;
• glycated - a compound of protein and glucose that circulates in the blood. This type of protein is detected in sugar tests;
• methemoglobin - associated with chemicals, its increase in the blood may indicate poisoning of the body;
• sulfhemoglobin - this hemoglobin molecule appears in the blood only when taking certain medications. The permissible level of hemoglobin of this type is no more than 10%.

The types of hemoglobin, as well as determining how much of it is in the blood, are detected only through laboratory diagnostics.

Norms

The hemoglobin formula implies an inextricable connection with the number of red blood cells, on the basis of which normal indicators are compiled. Average optimal indicator the level of this protein for an adult:

• in men – 125-145 g/l;
• hemoglobin in women is 115-135 g/l.

In addition, a color indicator is also used to determine the norm of a given protein in the blood. The optimal degree of saturation is 0.8-1.1. In addition, the degree of saturation of each red blood cell with hemoglobin is determined separately, average rate at the same time – 28-32 pictograms.

Violations in the structure

The structure of hemoglobin is unstable, and any disturbance occurring in it leads to the development of certain pathological processes. As a result of the influence of certain etiological factors may occur:

• the formation of abnormal forms of the protein - at the moment only 300 forms have been clinically established;
• the formation of a stable, oxygen-impermeable compound, carbohemoglobin, during carbon dioxide poisoning;
• blood thickening;
• decrease in hemoglobin, leading to the development of a certain degree of anemia.

An increase in protein is possible due to the following etiological factors:

• pathological increase in the number of red blood cells during oncological processes;
• increased blood viscosity;
• heart defects;
• burns;
• intestinal obstruction;
• pulmonary heart failure.

At the same time, it should be noted that among mountain residents, hemoglobin in the blood is constantly elevated, which is a normal physiological indicator. Also, the norms of this protein are overestimated in people who spend a long time in the fresh air - pilots, climbers, high-altitude workers.

A decrease in hemoglobin in the blood may be due to the following factors impacts:

• transfusion of large amounts of plasma;
• acute blood loss;
• chronic microbleedings: with hemorrhoids, gingival and uterine bleeding;
• hemolysis, leading to the destruction of red blood cells;
• deficiency of iron and vitamin B12;
• in pathological processes in the bone marrow.

In addition, a decrease or increase in this protein may be due to improper nutrition - if the body has an insufficient amount or, on the contrary, an excessive amount of certain products with the corresponding chemical composition.

Possible clinical picture

With low hemoglobin, the following symptoms may be present:

• fast fatiguability;
• dry skin and mucous membranes;
• weakness, general malaise;
• frequent dizziness;
• mental retardation and physical development in children;
• increased susceptibility to infectious diseases;
• sleep cycle disturbance;
• poor appetite or lack thereof.

It should be noted that low protein levels are most dangerous for children, as they lead to developmental delays.

An increased level of this protein in the body also negatively affects human health, which will manifest itself in the following clinical picture:

• jaundice skin and mucous membranes, tongue;
• pale skin;
• underweight;
• liver enlargement;
• increasing weakness;
• pigmentation on the palms and in the area of ​​old scars.

Both the first and second can lead to extremely negative consequences.

Carrying out analysis

Blood sampling to determine how many red blood cells are included in hemoglobin, as well as other laboratory data, is carried out as prescribed by a doctor. A hemoglobin test is taken in the morning, on an empty stomach. Also, the day before donating blood, you need to give up alcohol and drugs that affect hematopoietic system. Blood is drawn from a finger. The list of methods includes the following:

• colorimetry;
• gas measurement;
• determination of iron.

Only a qualified specialist can interpret this or that designation correctly. Therefore, after receiving the test results, you should take them to your doctor - he will determine your hemoglobin level and prescribe further therapeutic measures.