What is HDL cholesterol. What is cholesterol, and low and high density cholesterol? Causes and danger of changes in HDL in the blood
Cholesterol is one of the most important substances for any living being belonging to the animal kingdom. This fatty monohydric alcohol is one of the natural intermediate products of metabolic processes.
At the same time, it is cholesterol that is considered one of the "culprits" of atherosclerosis and some other diseases. After the discovery of the role of this substance in pathophysiological processes, cardiologists, nutritionists, and doctors of some other specialties took up arms against him. In fact, everything is not so simple and unambiguous, the trouble is not in cholesterol, as such, but in its quantity and the body's ability to absorb this substance properly.
Its function is to carry cholesterol from the liver to the cells. However, these lipoproteins are similar to arteries and can get "stuck" in the middle of the road, blocking the vessels that carry blood. Therefore, it is important to consume carbohydrates and sugars in moderation, as this exchange can be bad for cardiovascular health.
What are the safe levels of cholesterol for our body? - Aparecida Basso - retired, 68 years old. How is the diagnosis made? - Marcos Veras - Currently unemployed, 40 years old. No symptoms high cholesterol. Usually, people know that levels are high when doing lab tests.
About 80% of the need for this substance is provided by the body on its own, cholesterol is synthesized in the liver. The rest of the body receives from food of animal origin. It enters the blood in the form of complex complex compounds and is included in a number of processes, in particular:
- Growth and reproduction of cells, as one of the components of cell membranes and intracellular structures;
- Synthesis of hormones;
- Transportation of substances with antioxidant activity and fat-soluble vitamins;
- Synthesis of bile acids.
What is "bad" and "good" cholesterol
Cholesterol is insoluble in water, therefore, for transportation to target organs, it forms complex lipoprotein complexes. The complex has a spherical shape and consists of cholesterol esters and triglycerides coated with protein molecules.
A blood test that contains lipid and blood glucose values may already provide enough data for a doctor to make a diagnosis. However, additional tests may be required. Always look for your doctor, because only this specialist can confirm your diagnosis.
What are the forms of treatment? - Secretary Mirtes Andrade de Albuquerque, 47 years old. Most Recommended physical exercises, quit smoking, take care of food, reset excess weight and in the case of diabetes, glycemic control. All of the changes described above are part of treating or maintaining low cholesterol levels. It is necessary that you people with high level cholesterol understand who is responsible for your body and get a commitment to put in place lifestyle changes. This is important for maintaining heart and brain health.
There are several types of lipoprotein complexes in the blood, differing in composition and other physical and chemical properties. One of key features lipoprotein complex - density. On this basis, the complexes are just divided into “bad” and “good” cholesterol.
Low-density lipoprotein complexes are abbreviated as LDL and conventionally called "bad" cholesterol. Lipoproteins high density or HDL were called "good".
Statins are a group medicines used to lower cholesterol levels and can only be prescribed by a doctor after diagnosis and risk assessment of each patient. However, lifestyle changes are critical to prevention.
Can high cholesterol kill? - Joao Mendez - Tailor, 79 years old. On the normal levels Cholesterol is essential for the proper functioning of the body. Only when very high and uncontrolled for a long period of cholesterol can contribute to changes in cardiovascular system such as obstructions in the arteries.
In fact, both LDL and HDL cholesterol are vital to keep the body functioning.
"Bad" cholesterol
As part of LDL, this compound comes from the liver to target organs, where it is included in the synthesis processes. LDL are the precursors of many hormones, including sex hormones. The body's need for readily available cholesterol is higher, so LDL accounts for over 60% of all cholesterol present in the blood. The content of cholesterol derivatives in them reaches 50%. When moving in the bloodstream, loose complexes can be damaged and cholesterol esters, which are outside the protein coat, settle on the walls of blood vessels.
What is the relationship between eggs and cholesterol? - Sandra Maria Silvia - housewife, 33 years old. The amount of cholesterol in any food, including an egg, does not direct influence on blood cholesterol levels. This means that egg consumption, contrary to what many believe, does not increase these cholesterol levels.
In recent decades, several scientific research confirming that the consumption of eggs is not harmful to health. It is food that contains fatty acid, mono and polyunsaturated, important for arterial health. Does it hurt to eat eggs every day? - Felipe Bastos - student, 19 years old.
With excessive intake of LDL into the blood, the cells do not have time to absorb it completely, and the process of deposit formation on the walls of blood vessels accelerates. Atherosclerotic plaques form. The narrowing of the lumen of the vessels over time is manifested by vascular insufficiency, ischemia in the affected area. With the destruction of the plaque, a complete overlap of the lumen of the vessel is possible - thrombosis or thromboembolism.
In addition, the egg is an important source of protein, has fat-soluble vitamins, B vitamins, among which useful material such as choline, minerals, the carotenoids lutein and zeaxanthin. Saturated fats and trans fats should be avoided because they increase "bad cholesterol" which is bad for the arteries. Consuming large portions of carbohydrates, especially refined carbohydrates, is responsible for the increase in triglycerides and is also detrimental to cardiovascular health.
It is important that people have healthy habits and a balanced diet. Egg consumption, in addition to its many health benefits, is an inexpensive meal that is inexpensive and easy to introduce into the diet. Why is it known that eggs raise cholesterol levels? - Gustavo Di Natalie Silveira - Vet, 42 years old.
"Good" cholesterol
“Good” is popularly called high-density cholesterol complexes, HDL. These compounds transport cholesterol to the liver, where it is used to synthesize bile acids and excreted from the body. The content of cholesterol in the complexes is up to 30%. In people with a normal content of this fraction of lipids in the blood, the risk of myocardial infarction is reduced to almost zero. When moving through the bloodstream, HDL captures excess cholesterol from the walls, according to some reports, even from plaques formed. If HDL cholesterol is lowered, the body cannot cope with the cleansing of the walls of blood vessels, cholesterol continues to accumulate and atherosclerosis develops.
This recommendation was based on the increasing incidence of cardiovascular disease in the United States. However, it was not taken into account at the time of calorie intake, such as fats, refined foods and sugars ingested by humans. Later studies began to be conducted to prove that the egg does not increase the risk of the disease. In addition, recent studies have demonstrated countless benefits of egg consumption due to its significant nutritional properties.
What is the difference between fresh eggs and processed eggs? Marcus Aurelio - telemarketing clerk, 25 years old. An egg is a perishable food and some precautions are necessary for both purchasing and storage. As for the product itself, it must be free from cracks and cracks and free from dirt. As for storage, it is advisable to store it in the refrigerator or in a cool and ventilated place.
At the same time, it should be understood that the names "bad" and "good" cholesterol are more than arbitrary. What is HDL cholesterol? In fact, it is one of the final stages of lipid metabolism, “construction debris”, which, before being disposed of, should serve the body in good stead. Replacing all the "bad" cholesterol with good is impossible and unsafe. The main thing is not so much the absolute indicators of the content LDL cholesterol and HDL, and their balance.
However, an industrialized egg or "egg product" can be found in powdered or liquid form and maintain the same nutritional characteristics of an egg in nature. In this case, the industrialized egg has a longer shelf life and is easier, more practical, and safer to use in institutional kitchens because the egg goes through a pasteurization process that eliminates microorganisms.
Does Eggs in Butter Raise Food Cholesterol Levels? - Maria José - housewife 54 years old. However, everything will depend on complete nutrition of people. Fried eggs are a common and popular preparation not only in Brazil but all over the world, and maintaining nutritional balance through healthy practice can include a delicious cooked fried egg.
Norm of cholesterol in the blood
“Bad” and “good” cholesterol are not interchangeable compounds, they must always be present in the body, simultaneously and in a certain ratio. Deviation from the norm in the direction of increasing or decreasing the content of any of the fractions of cholesterol or any of its fractions indicates the presence serious problems in the body or a potential threat of their occurrence in the foreseeable future.
However, a boiled egg has the advantage of not containing additional calories. Avoid the point where the oil gives off smoke as this indicates the formation of acrolein which is toxic to the body.
- Change the way you prepare an egg within a week.
- This will reduce the consumption of fried foods.
- Use the medium temperature to heat the oil.
- Cooking oil cannot be reused.
Approximate levels of cholesterol:
- General - less than 5.2 mmol / l
- Triglycerides - no more than 2 mmol / l;
- LDL - up to 3.5 mmol / l
- HDL - more than 1.0 mmol / l
The concept of a norm is rather conditional. Cholesterol levels depend on gender, age, the presence of endocrine and other chronic disease, hereditary features lipid metabolism. This indicator is influenced by stress, physiological changes seasonal nature. The individual norm may differ slightly from the average values; in the presence of certain diseases and other risk factors, it is necessary to control cholesterol levels more strictly.
The blood test serves as a literal "eye" inside the arteries, looking for problematic agents that can give the doctor an accurate indicator of how far you've headed for a heart attack. Cholesterol and triglyceride tests are widely available for this. Cholesterol This is a substance that exists in all parts of your body: brain, muscles, bones and heart. And the body needs only a little to function normally. The extra cholesterol that results from an improper or poor diet causes fats to accumulate in the walls of blood vessels, clogging arteries and preventing blood from flowing.
About the individual norm and acceptable limits for each patient will tell the attending physician. He will give recommendations for effective lowering of cholesterol levels and, if necessary, prescribe treatment.
How to normalize cholesterol
First of all, doctors recommend to adhere to special diet. Foods containing trans fats are excluded from the diet, the consumption of animal fats and sweets is limited. It is better to replace fatty meat with fatty sea fish, which contains omega-3 and omega-6 polyunsaturated fatty acids.
If it is not processed in time, it may cause. heart attacks and strokes. "Good" and "Bad" Cholesterol There are three types of cholesterol in your blood: high-density cholesterol, low-density cholesterol, and very-low-density cholesterol. Today, experts say the risk is not with total cholesterol, but with a high ratio of "bad" cholesterol to "good" cholesterol.
Diagnosis of cholesterol Diagnosis is carried out by regular blood tests. inactivity, overweight and a diet rich in refined carbohydrates can raise triglycerides in the blood. To lower levels without using medication, police what you eat, exercise and get rid of sagging, especially around the waist. Remember: cholesterol and triglycerides have no symptoms.
If necessary, the doctor will prescribe drug treatment. The course of treatment includes:
- statins;
- Bile acid binders;
- Fibric acids;
- B vitamins, vitamin E, omega-3 fatty acids, folic acid.
High density lipoproteins circulate in the blood plasma. Their main property is anti-atherogenic. It is these lipoproteins that protect blood vessels from the deposition of atherosclerotic plaques on their walls. For this property, they (LPH) received the name good cholesterol, as they also remove excess cholesterol, transporting it to the liver. Some patients are concerned that HDL cholesterol levels are elevated on blood tests. This is especially true for people with problems in the cardiovascular system, in particular, those with a high risk of developing atherosclerosis.
Without a blood test, you won't know if you have high body fat until you have heart attack or a stroke. Homocysteine The amount of this modified amino acid in the blood rises after eating, rich in protein. high concentrations of this substance seem to cause problems with the arteries.
Recommendations If your cholesterol level is high, you should follow your doctor's recommendations, which may include. Exercise: Help increase levels of “good cholesterol,” which helps the body eliminate unnecessary cholesterol. You will also lose weight, which is great!
HDL provide the processing and removal of fats from the body, so they are called good cholesterol
The content of LDL and total cholesterol is also evaluated. It is important to know due to which fractions of lipoproteins the level of cholesterol is increased, or what it consists of at its normal numbers.
To determine the value of both cholesterol and lipoproteins of different densities, blood is taken from a vein in the morning, on an empty stomach. According to the results laboratory tests a lipid profile is formed containing the concentration in the blood of total cholesterol, high, low and very low density lipoproteins, as well as triglycerides. All indicators are analyzed first independently of each other, and then in aggregate.
Medication: When your diet fails to lower your cholesterol, your doctor will tell you a cure for it. Diet: Low-fat foods such as skim milk, lean meats, skinless chicken, fish, fruits, vegetables, rice, and beans. All cooked with little or no oil. Avoid frying and egg yolks.
Smoke: smoke; with high cholesterol and overuse alcohol can seriously damage your blood vessels. It is best to avoid alcohol and smoke! Oxidative theory of atherosclerosis. Lipid oxidation products have been detected by immunohistochemistry in both human and animal atherosclerotic lesions, which would be caused by certain cells in the arterial wall. clearly showed that these cells are able to oxidize lipoproteins. Oxidation of lipoproteins, regardless of the mode of oxidation of the lipoprotein particle, as well as the appearance of lipid oxidation products and degradation products such as aldehydes. indeed, the absorber receptor channel is not subject to negative feedback control.
Differences between HDL, LDL and VLDL
To understand the topic, first of all, it is worth learning what atherosclerosis is. Scientifically, this is a vascular disease caused by a violation of lipid and protein metabolism, which is accompanied by the accumulation of cholesterol and some fractions of lipoproteins in the lumen of the vessels in the form of atheromatous plaques. Simply put, these are deposits of cholesterol and some other substances in the vessel wall, which reduce its throughput. Consequently, blood flow becomes worse. Up to a complete blockage. In this case, the blood does not enter the organ or limb and necrosis develops - necrosis.
This massive accumulation of cholesterol esters transforms macrophages into foam cells, the first step in lipid band formation, and is cytotoxic to vascular cells, resulting in the release of lipids and lysosomal enzymes at the cellular level. intima, contributing to the progression of atheromatous lesions. It is an enzyme that hydrolyzes a large number of organophosphorus compounds, but its exact physiological role is poorly understood, but when the enzyme is inactivated, this protective role is abolished.
It is also interesting to note the decrease in paraoxanase activity in subjects with myocardial infarction, as well as in patients with familial hypercholesterolemia or diabetes, for whom there is an increased risk of developing coronary disease hearts. paraoxonase activity also decreases in the acute inflammatory phase.
Deposits of cholesterol and lipids in the walls of blood vessels lead to atherosclerosis.
All lipoproteins are spherical formations of varying density, freely circulating in the blood. Very low-density lipids are so large (of course, on a cell scale) that they are unable to penetrate the vessel wall. Accumulation does not occur and the atherosclerosis described above does not develop. But it is worth remembering that if they are increased, then the development of pancreatitis, a disease of the pancreas, is possible.
According to experiments, this variable but is about 30%. Several hypotheses have been proposed to explain this decrease in emissions. The first relates to the efflux of membrane cholesterol and is mediated by the lipid portion of the lipoprotein. We have not personally confirmed this correlation, so the proposed mechanisms are numerous and little known, and recent studies complicate things by using a peroxidase-based oxidation system that generates tyrosyl radicals. et al. made an unexpected observation.
Endothelin is indeed a vasoconstrictor mitogenic peptide involved in the development of atherosclerosis. The situation is therefore complex and new studies are needed to better evaluate the outcome of these antagonistic effects and their consequences in the development of the atheromatous process. Appeared new perspective in the fight against atherosclerosis.
Just low-density lipids are able to penetrate the vessel wall. Moreover, when the body tissues need them, lipids pass through the artery further, as they say, “at the address”. If there is no need, and the concentration in the blood is high, then LDL penetrate the wall and remain in it. Further, undesirable oxidative processes occur, which are the cause of atherosclerosis.
HDL is the smallest of the listed lipids. Their advantage lies in the fact that they can easily both penetrate the vessel wall and easily leave it. In addition, they have an antioxidant effect, inhibiting the process of transformation of low-density lipids into atherosclerotic plaques.
LDL cholesterol is considered “bad”, because when it is in excess, plaques appear in the walls of blood vessels, which can limit the movement of blood through the vessel, which threatens atherosclerosis and significantly increases the risk of heart disease (coronary disease, heart attack) and stroke
Now it becomes clear why high-density lipids are usually called good or useful cholesterol. It also becomes clear why it is worth evaluating not only total cholesterol but also its factions.
However, do not panic when reading the above mechanism. This does not mean that plaques are constantly formed in the vessels, and their subsequent blockage is only a matter of time. Normally, the mechanisms of lipid regulation work constantly. Only with age, in the presence of an unhealthy lifestyle or with various pathologies this process is violated. Accumulation does not happen all at once, in a matter of minutes or hours, but rather for a long time. But you should not delay treatment.
Reasons for the increase and decrease in HDL
We can safely say that it is more dangerous low level these lipoproteins than high. If in the analysis blood HDL increased, their increase is regarded as protection against atherosclerosis, an anti-atherogenic factor. Undoubtedly, under certain circumstances, overestimated figures of this indicator can cause concern, with too high figures, high density lipoproteins lose their protective properties.
An increase in HDL levels is not dangerous!
The reasons for increasing the level of this fraction of lipoproteins are as follows:
- Genetic mutations that result in overproduction or decreased excretion of good cholesterol.
- Chronic alcoholism, especially at the stage of liver cirrhosis.
- Primary biliary cirrhosis.
- Hyperthyroidism.
- Reception of some medicines: insulin, glucocorticoids.
- Familial hyperalphapipoproteinemia. It is not accompanied by any symptoms, nothing bothers the patient, it is detected as an accidental finding.
- Perhaps an increase in the rate in women preparing to become a mother. This is especially true for later dates pregnancy, when the rate can almost double.
High cholesterol during pregnancy is due to the fact that in the body there is an increase in lipid metabolism and the synthesis of hormones by the adrenal glands.
The reasons reduced content HDL:
- Diabetes.
- Hyperlipoproteinemia type IV.
- Diseases of the kidneys and liver.
- Acute viral and bacterial infections.
You need to understand that one indicator of HDL is not proof of one or the state of the body. It can only be taken into account in comparison with the level of total cholesterol and LDL.
This is expressed, first of all, in the so-called atherogenic coefficient. It is calculated according to the following formula: high-density cholesterol is subtracted from total cholesterol, and then the resulting figure is divided again by HDL. The resulting coefficient is compared with normal values. On average, it should not be higher than 2.5-3.5 for men (depending on age) and no higher than 2.2 for women. The higher the ratio, the higher the risk of coronary heart disease. By including simple mathematical logic, one can understand that the higher the total cholesterol and the less lipoproteins, the more the value of the coefficient will increase; and vice versa. Which again proves the protective function of high-density proteins. Therefore, if both cholesterol and HDL are elevated, this means that in general the coefficient will be low, but it is worth thinking about reducing the cholesterol content in the blood. If only HDL is elevated, this means that there is no cause for concern.
It is impossible to correlate proteins of high and low density through any coefficient. They are evaluated independently of each other.
What can be done
If the reasons for the increase in high-density lipoproteins remain unknown and there is concern for your health, then you should visit your doctor. This is true if blood was donated, for example, as part of a medical examination or for some other reason not directly related to going to the doctor about problems with the cardiovascular system.
Do not worry if the doctor prescribes additional methods examinations. They are needed only for a comprehensive study of the causes of changes in blood parameters.
Two weeks prior to the study, lipid-lowering drugs should be discontinued unless the goal is to determine the effect of therapy with these drugs in the analysis.
The doctor's recommendations will contain simple, but very important remarks. To begin with, you should limit the intake of fats, in particular, saturated fats contained in butter, lard, lamb fat, margarine and a number of other products. They should be replaced with polyunsaturated fats, which include olive oil, salmon fish and others. If you are overweight, you should lose it. This is achieved by adjusting nutrition and increasing physical activity. Try to stop drinking too much alcohol and stop smoking completely.
In the event that the indicators go far beyond allowable norms, then it can be assigned drug therapy. But its effectiveness will be many times higher also if the above recommendations are followed.
An increase in the level of cholesterol in the blood, as well as its individual fractions, at first glance, may seem dangerous. But do not worry and panic ahead of time.