Atherosclerosis in blood vessels : let`s investigate this pathology as if we are medical spies

Dear reader, if you have looked at this article, it means that the topic of atherosclerosis has affected you to some extent and you already have some information about this disease.

I suggest considering the following questions about atherosclerosis:

1. What is atherosclerosis?
2. How does it form?
3. How does it manifest itself?
4. A few “clinical oddities”
5. How long does it take for atherosclerosis to make itself known?
6. At what age does atherosclerosis begin to appear?
7. Possible causes of atherosclerosis?
8. Can the patient himself influence the course of atherosclerosis?

1. What is atherosclerosis?

Atherosclerosis (generally and precisely known) is a chronic disease in which, due to various reasons, atherosclerotic plaques form in the walls of some arteries.

Here is a definition taken from Wikipedia:

Atherosclerosis (from the Greek αθήρα — “porridge” + σκλήρωσις — “hardening”) is a chronic disease of the arteries of the elastic and muscular-elastic type, arising as a result of a violation of lipid and protein metabolism and accompanied by the deposition of cholesterol and some fractions of lipoproteins in the lumen of the vessels.

Here is another definition taken from the book: Литовский И.А., Гордиенко А.В. Атеросклероз и гипертоническая болезнь. С.-Пб., Спецлит. 2013. 312 с.

Atherosclerosis is a systemic disease that initially affects the vessels, but not all of them, but only the arteries, in the walls of which cholesterol and its esters accumulate, forming plaques characteristic of this disease.

The following definition is also of interest [Sergienko S.V., Ansheles A.A., Kukharchuk V.V. Atherosclerosis and dyslipidemia: modern aspects of pathogenesis, diagnosis and treatment. M.: Patiss; 2017 (in Russ.)]
Atherosclerosis is a variable combination of changes in the inner lining of the arteries, including the accumulation of lipids, complex carbohydrates, fibrous tissue, blood components, calcification and associated changes in the middle lining.

As you can see, most definitions mainly reflect the morphological aspect of this pathology. And what practical significance does all this have? Well, we know that something is deposited in the walls of blood vessels. I think what is important here is that these plaques cause some symptoms.

Let’s give a definition of this disease that would also take into account its clinical sphere.

Atherosclerosis is a chronic systemic disease of the vascular system, which manifests itself in the formation of plaques mainly on the walls of arteries, where these plaques in advanced cases lead to a disruption of the blood supply to their organ, which in turn is expressed by the corresponding clinical picture.

2. How does it form?
   At the moment, medical science offers many theories that try to explain the occurrence of atherosclerosis.

As the author of the article, I like the following theory described in the article “Basic mechanisms of Atherosclerosis by Magnus Back and Goran Hansson” (Chronic coronary artery disease, 2018). The authors define this pathology as follows: atherosclerosis is a chronic inflammatory process caused by the accumulation of cholesterol-containing low-density lipoprotein particles in the walls of arteries.

As you can see, atherosclerosis is always accompanied by inflammation in the vascular wall.

Different authors distinguish different stages of plaque formation. Here is one option.

Atherosclerotic changes in arteries and veins include 5 stages:
a) First, local damage to the wall of the blood vessel occurs.
b) At the site of damage to the endothelial cells that line the arteries and veins, lipoproteins begin to leak out. They are then subjected to oxidative processes that cause the body’s immune response.
c) Neutrophils, lymphocytes, monocytes and macrophages – types of leukocytes designed to free the blood vessels from foreign agents – are sent to the site of inflammation.
d) When absorbing oxidized lipoprotein molecules, white blood cells are transformed into foam cells (they are filled with fats).
e) Dying, lipid-saturated foam cells form atherosclerotic plaques.
This is a fairly simplified diagram of plaque formation. In reality, everything is much more complicated, and in this process there are always opposing forces: inflammation and anti-inflammation; destruction and creation, etc.

3. How does atherosclerosis manifest itself?

A vascular plaque is unpleasant because it blocks the lumen of the affected artery. And this at a certain point leads to a deterioration in the blood supply to the area of ​​the body for which this affected artery is responsible.

The deterioration in blood supply can be gradual or rapid (and even sudden).

The following vessels are most often affected: carotid arteries; coronary arteries; arteries of the lower extremities; arteries of the abdominal cavity.

Scientists have noticed that, as a rule, atherosclerotic plaques begin to appear and become noticeable in places where arteries branch (bifurcations). According to the views of the same researchers: they believe that the bifurcation sites of arteries are characterized by greater vulnerability of the endothelium from the blood flow, that is, in these areas there is a greater probability of damage to the endothelium, hence the penetration of the same lipoproteins (for example, LDL).

4. A few “clinical oddities”.

Point 1. Look: most definitions consider atherosclerosis a systemic disease. That is, all plaques in all arteries of the body occur according to a single pattern. It would seem that atherosclerosis should be under the supervision of one specific medical specialist (let’s call him an “artery doctor”).

But at the same time, at present:

• complications from plaques in the carotid arteries are usually treated by a neurologist;
• complications from plaques in the coronary arteries are usually treated by a cardiologist;
• complications from plaques in the arteries of the lower extremities are usually treated by a vascular surgeon.
• and complications from plaques in the arteries of the abdominal organs can be treated by anyone (gastroenterologist, nephrologist, surgeon), since these complications can imitate common pathologies of the abdominal organs.

Point 2. Atherosclerotic plaques, as a rule, occur in the arteries and are practically absent in the veins. Scientists explain this by the fact that the arteries have much higher blood pressure and higher blood flow speed. That is, these are some significant “damaging” factors. Let’s agree with this for now.

Point 3. Plaques are found in the arteries of the neck, head, legs. But these plaques are almost never found in the arteries of the arms (at least they do not express themselves clinically). How can this be explained? Are the arteries of the arms special in some way from birth? I don’t think so. The following explanation comes to mind: the arms are constantly moving.

Point 4. Researchers write that plaques in arteries most often occur in places where they branch (bifurcations). If it is only a matter of bifurcations, then: why are plaques not found in the arteries of the arms? There are many arterial bifurcations in the vessels of the upper extremities.

5. How long does it take for atherosclerosis to make itself known?

The formation of a vascular plaque is a long process. From the moment of onset to the manifestation of symptoms, years or even decades can pass. Here is what clinical scientists say. For example, for noticeable symptoms to appear in the heart, a plaque in the coronary arteries needs from 10 to 20 years from the moment of onset, and a plaque in the carotid arteries from 5 to 15 years.

6. At what age does atherosclerosis begin to appear?

Unfortunately, blood lipid deposits in the walls of blood vessels begin to appear in childhood. But vascular plaques most often begin to manifest themselves in people over 40 years old. And the older you are, the more extensive the atherosclerosis manifests itself. In general, we can say that with age, the set of factors that contribute to the development of atherosclerosis increases.

7. Possible causes of atherosclerosis?

Here it is more appropriate to talk not about causes, but about risk factors.

Official science talks about the following risk factors:

• age: this factor can be argued. There are many cases when very old people do not have signs of atherosclerosis. Although we must agree that with age, various “breakdowns” of the body accumulate, which contribute to the development of plaques in the vessels.
• genetics: a completely justified factor, and yet, I believe that genetics manifests itself to a greater extent through lifestyle (epigenetics).
• gender: men are more often affected by atherosclerosis. Most likely, this occurs due to the peculiarities of the endocrine system of men.
• high cholesterol: I think that this is also a controversial factor. Currently, there is no unambiguous data that would show a direct dependence of the occurrence of plaques on the level of cholesterol in the blood. There are many cases when a patient has a normal cholesterol level, and the vessels are heavily affected by plaques.
• concomitant diseases (obesity, hypertension, diabetes mellitus, etc.). Unfortunately, the listed diseases make a significant contribution to the development of atherosclerotic plaques. These diseases are often accompanied by deterioration of the vascular endothelium.
• bad habits (smoking, alcohol): these are definitely harmful factors. Smoking increases oxidative stress.
• low physical activity: nature created us to move, not lie on the couch.
• unhealthy diet: if you put poison in yourself, you will get poisoned. Unhealthy food can only give you unhealthiness if this food contains – a lot of flour products, sugar, trans fats.
• chronic stress. Long-term stress makes the body release stress hormones into the blood. These are cortisol, adrenaline, noradrenaline.

8. Can the patient himself influence the course of atherosclerosis?

Atherosclerosis has become widespread among the population over the past 50 years. What has changed during this time? What about the biology and physiology of the human body. It is unlikely that the physiology of the body has changed at all: 50 years is a moment for evolution in general. The reasons must be sought in the areas of ecology and lifestyle. Unfortunately, we, people, have begun to rely more often on the achievements of technical progress, and are moving further and further away from nature.

Conclusion: Common sense, compliance with the laws of biology and physiology, a positive psychological attitude, and careful attitude towards your body, I think, these are the main keys that can prevent the occurrence of atherosclerosis.

Postscript: I deliberately did not cite the sources of clinical studies. You can easily find them on the Internet.

Be healthy!