Hemoglobin is a substance contained in red blood cells, absolutely essential for life, as it absorbs the oxygen introduced into the body with breathing, and transports it to the organs that use it for energy.
Hemoglobin is a molecule present inside red blood cells, essential for the transport of oxygen in our body. Hemoglobin also gives red color to red blood cells, or erythrocytes, and is one of the most performed blood tests, given the low cost of the test and the large amount of information it provides. In the presence of low hemoglobin or anemia, or high hemoglobin, diagnostic investigations are necessary to rule out the presence of pathologies related to the marrow or other organs. Often even an incorrect diet can cause changes in blood counts.
WHAT IS HEMOGLOBIN (Hb)
What is hemoglobin? Hemoglobin, or Hb, is a tetrameric protein with a globular structure, present in red blood cells, composed of four subunits equal to two by two, each consisting of a polypeptide chain (α or β) and a heme group, that is to say a non-protein molecule containing iron to which an O2 molecule can bind.
FUNCTIONS OF THE HEMOGLOBIN
What is hemoglobin used for? Its main function is to transport oxygen O2 through the blood, it can also bind and transport other molecules such as nitric oxide (- NO - vessel muscle relaxant), carbon monoxide (CO) and cyanide (CN) , all toxic and harmful.
NORMAL VALUES OF HEMOGLOBIN
What are the normal values of HEMOGLOBIN? At the time of birth the average hemoglobin values in the umbilical cord are equal to 16/17 g / 100ml, in the weeks following the birth a modest reduction in hemoglobin is observed, up to the age of 10 there are values equal to 12 / 13 g / 100 ml, subsequently there is an increase in values which, after puberty, reach those of adults. After the 50th year there is a progressive reduction in hemoglobin levels. At the age of 65, values equal to 12 g / 100 ml are to be considered physiological. The reduction is due to a decrease in bone marrow production. The values vary according to sex, the mean values in men are 15.8 g / 100 ml and in women 13.9 g / 100 ml.
HEMOCHROME AND ITS ERITROCYTARY PARAMETERS
MCV (mean corpuscular volume) is perhaps the most important. It is the average corpuscular volume of red blood cells. Red blood cells can be small, large, or normocytic. It varies between 82 and 92 fl (femtoliters):
- High MCV if it is higher than 95 fl, in this case we speak of macrocytic anemias;
- Low MCV when the value is less than 80 fl and in this case we speak of microcytic anemias.
MCH (mean cell hemoglobin) is measured in picograms. It is the average content of Hb in the red blood cells.
MCHC (mean corpuscular hemoglobin concentration) is the average concentration of hemoglobin in red blood cells. Normal value is between 32-33% and 36%:
- High MCHC can indicate spherocytosis, folic acid and Vitamin B12 deficiency, liver disease;
- Low MCHC may indicate iron deficiency anemia.
RDW (red cell distribution width) measures the variability of the size or volume of red blood cells. The normal value is between 12 and 15%. Higher values indicate that the RDW is high and there may be iron, vitamin B12, folic acid deficiency or a recent blood transfusion.
It allows to evaluate structural hemoglobin anomalies. It is based on an analytical-separative technique that monitors the movement of electrically charged particles under the effect of an electric field if they are in a medium of fluid consistency. With this technique, Mediterranean anemia or beta-thalassemia and other forms of anemia are diagnosed.
We speak of high hemoglobin when the values exceed those that are considered "average" in the individual. High hemoglobin is often asymptomatic and is found randomly in blood tests done for other reasons.
Causes of high hemoglobin
What are the main causes of high hemoglobin? This can manifest itself:
- in particular climatic conditions such as those present at high altitudes. At high altitudes oxygen is rarefied and, therefore, the body compensates for the lack of oxygen by synthesizing a greater number of red blood cells;
- in case of fever when associated with vomiting and dehydration;
- in competitive doping the increase can also be induced voluntarily when it is desired to increase the oxygen supply to the tissues by resorting to the use of drugs that stimulate the red blood cell production process (EPO, erythropoietin);
- in the presence of some forms of cancer;
- in polycythemia vera (also called Vasquez's disease);
- with cigarette smoke;
- in the presence of COPD (Chronic Obstructive Pulmonary Disease).
It is in the presence of low hemoglobin when the levels in the blood have values lower than those considered "normal", that is, below. It is always necessary to relate the values measured with the patient's age, sex, diet and any pathologies he suffers from. Normally a low hemoglobin value indicates anemia and the causes can be the most diverse, the most common are:
- nutritional factors: iron deficiency, folic acid deficiency, vitamin B12 deficiency (pernicious anemia);
- gastrointestinal bleeding: can occur in the presence of ulcers caused by non-steroidal anti-inflammatory drugs or in the event of colorectal cancer;
- menstrual cycle: women generally have lower hemoglobin values due to the loss, more or less abundant, of blood during the menstrual period;
- kidney problems: nephritis or damage to the kidney parenchyma;
- defects present in the synthesis of red blood cells: there may be genetic diseases due to alterations concerning the genes responsible for the synthesis of hemoglobin chains.
- defects related to the marrow production of red blood cells in the presence of oncohematological diseases, for example:
- myeloproliperative syndromes
- multiple myeloma
- surgical interventions: small interventions such as those of dental implantology and removal of cysts cause a lowering of hemoglobin due to any bleeding;
- Radiotherapy and chemotherapy: in the treatment of neoplasms (leukemia and other tumor pathologies of the figurative elements of the blood) there is a decrease in hemoglobin as a secondary effect of the use of chemotherapy drugs (anaplastic effect).
- The lowering of hemoglobin values can also occur in the case of:
- cirrhosis of the liver
- bacterial infections
- pregnancy, systemic lupus erythematosus (SLE) and other rheumatological diseases
- Addison's disease
Anemia is the main manifestation of low hemoglobin. The term anemia originates from the Greek and literally means "lack of blood".
Low hemoglobin symptoms
The most common symptoms of low hemoglobin or anemia that arise are:
- INTERCOSTAL PAIN
- COLD TO THE LIMBS
These are diseases that concern qualitative hemoglobin abnormalities connected to point-like mutations of one of the genes that encode the protein chains of hemoglobin. The genetic defect involves the loss or modification of an amino acid that is part of the globin chain, modifying the three-dimensional structure of the molecule and, in this way, alters its function.
They are caused by mutations that lead to the synthesis of hemoglobins with a different sequence than normal:
FALCIFORM OR DREPANOCYTOSIS ANEMIA (HbS)
It is a form of anemia characterized by the presence of sickle-shaped red blood cells. Sickling of red blood cells is particularly relevant only in homozygous individuals in whom all blood contains HbS. These red blood cells are rigid and cause tissue anoxia, they are then destroyed by the spleen and other blood-producing organs. Vascular obstructions and heart attacks occur that can affect different organs: brain, kidney, bones, lungs.
HEMOGLOBINS C, D, E
A further mutation of the β gene encodes the amino acid and produces hemoglobin C. HbC is less soluble than hemoglobin A and has a tendency to crystallize within red blood cells.
Most common disease in South-East Asia, whose clinical manifestation requires the coexistence of multiple mutations, as each cell contains 4 genes for the α chain of hemoglobin. The state of complete absence of the α chains is incompatible with life (fetal hydrops), as the α chain becomes part of all major hemoglobins.
It occurs when both alleles of the genes for the hemoglobin beta chain are mutated. This condition causes severe microcytic and hypochromic anemia, major splenomegaly and bone deformities.
MINOR THALASSEMIA, BETA THALASSEMIA OR MEDITERRANEAN ANEMIA
It is the mildest form of beta thalassemia, involving microcytic anemia with low Hb, low MCV and high red blood cells. It often requires chelation therapy for iron, since the increased turnover of red blood cells leads to the accumulation of iron in organs and tissues.
LOW HEMOGLOBIN AND IRON DEFICIENCY: WHAT TO EAT
In case of iron deficiency, a meat-based diet is recommended, especially liver and red meat.
THEY ARE RECOMMENDED:
Meat: fillet or steak of adult bovine, veal, pork and horse meat cooked on the grill, grilled, grilled, liver, spleen, lung, kidney and offal.
- Fish: mackerel, salmon, sea bream or sea bass steamed, grilled or in the oven.
- Vegetables / vegetables: bean sprouts, rocket.
- Sweets: unsweetened cocoa powder and dark chocolate (in a percentage of 85% of cocoa upwards).
- Legumes: beans, fresh broad beans, lentils and chickpeas stewed, in a pan and with pasta.
FOODS NOT RECOMMENDED
- Dairy products, coffee and tea decrease the absorption of iron contained in food.
LOW HEMOGLOBIN AND LACK OF FOLATES AND VITAMIN B12: WHAT TO EAT
In case of Vitamin B12 deficiency:
- it is necessary to resort to a diet of animal origin rich in proteins, mainly meat and fish and, to a lesser extent, dairy products and eggs.
In case of Vitamin B9 deficiency (folic acid or folate):
- it is necessary to use green vegetables such as lettuce, spinach, broccoli, artichokes, asparagus as well as legumes and some types of fruit such as strawberries, oranges and dried fruit.
WHEN TO TAKE THE EXAMS?
The hemoglobin dosage is an analysis that is normally requested, the specific value falls within the framework of more general analyzes (blood count) with which we diagnose alterations at the level of each element figured in the blood. The presence of hemoglobin in the urine, called hemoglobinuria, may be the consequence of intravascular or intravesical hemolysis involving red blood cells and should not in any case be confused with hematuria (urinary blood loss).
GLYCATED OR GLYCOSYLATED HEMOGLOBIN:
Glycated hemoglobin (HbA1c) refers to the hemoglobin associated with glucose. In the presence of high glucose concentrations, hemoglobin tends to bind carbohydrate fragments to its molecule. It is a typical condition that occurs in people with diabetes who are unable to adequately control the disease. When the blood glucose exceeds the threshold considered normal, a total saturation of the hemoglobin of the erythrocytes occurs and in this case it is referred to as: glycohemoglobin. The glycosylation of hemoglobin is a permanent change that remains in the erythrocytes for their entire half-life (120 days) and for this reason it is advisable to monitor the situation of patients who have undergone insulin therapy for diabetes.
The values of glycated hemoglobin must remain between 4 and 6%.
HIGH GLYCATED HEMOGLOBIN: CAUSES AND SYMPTOMS
We speak of high glycated hemoglobin when the values of glucose concentration in hemoglobin are higher than 8%. Generally it is in the presence of a form of diabetes mellitus. It is very important to undergo blood tests because diabetes, in the initial phase, does not present any symptoms.
HOW TO LOWER GLYCATED HEMOGLOBIN:
A series of measures must be put in place to keep blood sugar levels under control:
DIET - it is advisable to avoid foods that have a high glycemic index (especially sweets and alcohol) without completely excluding carbohydrates such as wholemeal bread, pasta and rice. Foods such as legumes, sweet potatoes, green leafy vegetables, berries, and low-fat dairy products are recommended.
PHARMACOLOGICAL THERAPY - on the market there are antidiabetic drugs (metformin sulfonylureas, glitazones, acarbose) which have the effect of lowering blood glucose.
Gestational diabetes occurs in approximately 5% of pregnancies. Keeping glycemic levels under control is very important both for fetal health (in fact, the incidence of macrosomia increases and in adult life it is a predisposing risk factor for the onset of obesity, hypertension and diabetes) and for maternal health (women who have had gestational diabetes have a 50% risk of developing diabetes over 10 years). Diabetes in pregnancy is kept under control with dietary precautions and the use of insulin. To understand if the glycemic compensation is optimal, it is recommended to evaluate HbA1c every 3 months.
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