Hypercholesterolemia is a certain pathological syndrome that is not a disease, in the usual sense of this. Rather, it is a prerequisite for the development of certain diseases. As a result of certain violations (as a result of genetic defects and secondary disorders) in the body increases the level of certain substances that are the results of fat metabolism processes. Deferred in biological tissues, these substances cause blockage of blood vessels and various disorders in the whole body. It is hypercholesterolemia that is the cause of such diseases as atherosclerosis and obesity .
Hypercholesterolemia is a complex syndrome that is characterized not only by pathophysiological disorders, but also by factors such as a violation of the normal diet, psychological problems and endocrinological disorders.
In principle, hypercholesterolemia is the "cradle" of the development of the most common diseases of the human population: cardiac and vascular lesions. It is important to correctly understand the processes of its genesis and the pathological action that hypercholesterolemia has on the body. It is useful to know about hypercholesterolemia for everyone: both physicians and ordinary people. This will help to apply preventive measures to identify this disease.
In order to understand the pathogenesis of hypercholesterolemia, it is first necessary to study the processes of lipid metabolism.
Under normal conditions, fats of different types enter the human body. The main ones, those that participate in energy and various anabolic processes are triacylglycerides, free cholesterol and compound lipids.
After these fats enter the body, each of them undergoes its cleavage processes. Triacilglycerides under the action of pancreatic and bile acids decompose to smaller components. Similarly, other lipids are absorbed: cholesterol is absorbed in the free state, its more complex compounds are cleaved by enzymes.
Further, the split and lighter fats are absorbed by the enterocytes. These are cells of the small intestine that absorb nutrients from the chyme, a food lump that moves along the human gastrointestinal tract during the process of digestion. In enterocytes, the split fats are converted into their transport forms. They are called chylomicrons. Chylomicrons are microscopic fat droplets, covered with a layer of active proteins and phospholipids. Further, chylomicra through the membrane of enterocytes travel to the lymphatic system, and through it enter the peripheral bloodstream.
Here it is necessary to say that chylomicrons can not independently get into the necessary organs for their further transformation, for this they need the help of other components. This help is provided by blood lipoproteins - special complexes of blood lipids, connected with proteins. Lipoproteins help chylomicrons not to dissolve in the blood before the time, before they reach the necessary organs. Lipoproteins differ in their density and are divided into the following subclasses:
- Lipoproteins having a very low density (VLDL)
- Lipoproteins characterized by low density (LDL)
- Lipoproteins with intermediate density (LDL)
- High density lipoproteins (HDL)
It would seem that a very simple classification, but it occupies the leading place in the prerequisites of hypercholesterolemia. Each of these lipoproteins is involved in the transport of certain lipids. Hypercholesterolemia develops due to a disruption in the function of lipoproteins, which consist in the capture and transport of lipids into tissues.
The most important role in the transport of chylomicrons is played by very low and low density lipoproteins. These lipoproteins appear in the liver cells and are directed along the vessels to the enterocytes, where they bind to the chylomicrons and transport them to the tissues. The main specification of these lipoproteins is the transport of triglycerides.
LDL is the main "transport" for cholesterol. They carry cholesterol to the necessary organs.
Lipoproteins, which are highly dense, appear in the cells of the liver and small intestine, having a very special function. They are engaged in "pulling" excess cholesterol from tissue cells. These are the most important "defenders" of the body, which perform an "anti-atherogenic" function.
Thus, HDL are lipoproteins "protectors", and lipoproteins that have a low density - this is "transport" for the converted fats.
It is low density lipoproteins that can cause hypercholesterolemia. But this happens only when low density lipoproteins are "disoriented", that is, they lose the function of carrying the chylomicrons along the tissues that need them. It is then that a general condition develops, such as hyperlipoproteinemia (hypercholesterolemia is its subspecies).
Hyperlipoproteinemia is characterized by a pathological increase in the amount of lipids in the blood. Accordingly, hypercholesterolemia, by analogy, will be a condition in which the blood will increase the level of cholesterol. As you guessed, low-density lipoproteins will be "guilty" for the appearance of hypercholesterolemia, which will transport excessive cholesterol to cells and tissues.
The reasons why suddenly in a normally functioning organism there are similar problems, a few. According to them, the disease is divided into primary hypercholesterolemia and secondary hypercholesterolemia.
The pathogenesis of hypercholesterolemia
Primary hypercholesterolemia develops due to violations of the genetic structure. Main reasons:
1. Defects of the protein part of lipoproteins. As a result, low-density lipoproteins can not dock with tissues and give them chylomicrons with cholesterol.
2. Violations of the synthesis of transport enzymes involved in the processes of interaction of chylomicrons with lipoproteins. As a result, there is no transport of them to the right segments of the body, and in the blood absolutely unnecessary cholesterol accumulates there.
3. Disturbance of the structure of receptors of tissue cells to lipoproteins. And here the following situation occurs: both enzymes are needed, and lipoproteins are in perfect order, but they can not connect to tissue cells. In their own words, they can not make a "landing" in a certain tissue.
Secondary hypercholesterolemia is a consequence of various acquired disorders. This includes alcoholism, just the aforementioned errors in the diet, wrong lifestyle, endocrinological disorders, liver and kidney damage, etc. They all lead to disruptions in the normal transport of fats from enterocytes to tissues.
Also, types of hypercholesterolemia are distinguished, according to the disturbances in the function of production and the utilization of lipoproteins: Production (increased lipoprotein formation) and reduction (disruption of lipoprotein utilization).
Hypercholesterolemia according to ICD 10
Hypercholesterolemia is such an important pathological process that it is even isolated into separate forms according to the international classification of diseases and has its own special cipher. The cipher of pure hypercholesterolemia for ICD 10 is E78.0. It belongs to the subdivision of diseases with a violation of lipoprotein metabolism (general cipher E78).
The main indicators of hypercholesterolemia is the appearance in the body of cholesterol "deposits" - deposits of cholesterol in tissues.
In the field of tendons, especially the Achilles, extensor muscles of the fingers and toes, tuberous formations - xanthomas appear. They are clusters of cholesterol deposits on the tendons.
On the eyelids, yellow and orange spots appear near the nasal corner. These are xantelasms, they are also cholesterol deposits.
Another extremely interesting manifestation of hypercholesterolemia is the appearance of a gray band on the periphery of the cornea.
Most often, hypercholesterolemia is manifested due to its secondary symptoms. That is, due to the development of vascular lesions and as a consequence of this development of atherosclerosis, damage to the heart muscle, stroke.
The most vivid manifestations of hypercholesterolemia appear during the development of atherosclerosis. A huge range of manifestations, a feature of which is the defeat of various vessels: from the vessels of the brain to small vessels of the extremities.
Depending on the lesion, the symptomatology of hypercholesterolemia will be different.
But it must be said that clinical signs are a consequence of the advanced stages of hypercholesterolemia. Before the level of cholesterol in the blood becomes critical, pronounced symptoms may be absent.
Diagnostic criterion of hypercholesterolemia is the study of a special lipid profile of blood. It will determine the levels of individual lipids: low and high density lipoproteins, triglycerides and cholesterol in the blood. It is in the presence of an increase in these four indicators that hypercholesterolemia is diagnosed.
One of the subspecies of primary hypercholesterolemia is familial hypercholesterolemia. It occupies type 2 in the general classification of hereditary hyperlipidemia. It is that as a result of genetic disorders, lipoprotein can not contact cholesterol and transfer it. In addition, the second factor of this disease is the simultaneous increased synthesis of cholesterol in the body.
As a consequence, the above signs of cholesterol deposition in tissues are manifested in patients: xanthomas, xanthelasms and senile arch (the second name is "corneal arch").
In addition, with familial hypercholesterolemia, early infarctions of "young" myocardial infarctions appear: the average age of onset of this disease in patients with familial hypercholesterolemia will be younger than 30 years. This is the only type of disorder that causes hypercholesterolemia in children.
By the way, there is one interesting fact. If you carefully look at the portrait of Mona Lisa, you can find her signs of family hypercholesterolemia: xanthoma on the hands, xantelasm in the corners of the eyes.
The treatment of hypercholesterolemia is very important, and in hereditary forms it is vitally important.
Drugs for the treatment of hypercholesterolemia
The main role in the treatment of hypercholesterolemia is given to statins. This is a special class of drugs that deals with lowering cholesterol. They block the enzyme, which increases the synthesis of cholesterol. Typically, use atorvastatin.
Healthy lifestyle for the correction of hypercholesterolemia
Also an important element in the treatment of hypercholesterolemia is a lifestyle change: adjust the amount and quality of food consumed, and assign sports loads. If in 4-6 months the level of low density lipoproteins (atherogenic lipids) does not decrease, then the treatment with statins is started.
In addition to statins, hypercholesterolemia is treated with fibrates (derivatives of fibroic acid) and sequestrants of bile acids (they will intensively break down excess cholesterol).
Diet for hypercholesterolemia
But one of the important complexes, which is used simultaneously with the treatment of hypercholesterolemia, is a special diet.
With hypercholesterolemia, you need to remove fast food, butter, various smoked meats, yolk eggs, offal, very fatty meats, sweets and buns from the diet.
It is recommended to include in the diet of patients with hypercholesterolemia more fruits and vegetables, vegetable oil, cereals and bread, low-fat fish, low-fat dairy products. You can also eat lean meats. A good example for remembering how much meat for patients with hypercholesterolemia needs to be consumed per day is "an example of a deck of playing cards": in a day you can consume meat no more than the size of a deck of playing cards.
Also a good diet for hypercholesterolemia is the "dish model": a dessert plate is taken, mentally divided in half. Half of this plate is vegetables and root vegetables, one fourth of the dish is taken for garnishes, and only the second quarter is light meat or fish.