What is cholesterol?
Cholesterol, like triglycerides, is part of the body’s fats, also known as lipids. Lipids are present in the structure of all cells, as they form part of the membrane (wrapping). They are used as raw material for the synthesis of some hormones and, when metabolized, produce energy. The level of cholesterol in the blood depends in part on the amount and type of fats that are taken with food, but mainly comes from its manufacture by the body itself in the liver.
A high blood cholesterol level is not a problem in the short term, but if sustained for a long time, it accelerates the development of arteriesclerosis, an age-related degenerative arterial process, consisting of hardening and narrowing of arteries. They carry blood to different organs and body parts.
It is often said that there are two types of cholesterol: the “good”, called high-density lipoproteins (HDL), and the “bad”, made up of low-density lipoproteins (LDL).
LDL transports and transfers cholesterol to all tissues and its excess favors artery disease (cardiovascular disease). HDLs, on the other hand, have a beneficial effect, by collecting excess cholesterol and returning it to the liver. In this way they prevent the development of atherosclerosis.
The ratio between both forms of cholesterol (LDL and HDL) is what actually influences the appearance of atherosclerosis and its complications at premature ages (what is called the cardiovascular risk for thrombosis in the heart, brain, etc.) .
The level of LDL cholesterol can be reduced with a low-fat diet and, if necessary, with medications. The level of HDL cholesterol can be increased by exercise, reducing excess weight and quitting smoking.
What is cholesterol measurement?
It is performed by a blood test, preferably after having fasted for 12 hours, in order to calculate the levels of all forms of cholesterol. It is difficult to determine what the normal cholesterol levels are, as they increase with age. In addition, women usually have a higher level of HDL than men, until menopause.
On the other hand, the importance of high cholesterol is very different, in addition to the ratio between LDL and HDL, according to the existence of other risk factors for atherosclerosis, such as smoking, diabetes and high blood pressure (hypertension), or a history With cases of cardiovascular disease. It is possible, for example, that a person has a high cholesterol level and his cardiovascular risk in the end, is relatively low because of the absence of other risk factors and antecedents in his family.
Although there are differences between normal cholesterol levels for each sex and age, as a general guideline, the following categories can be given, depending on total cholesterol levels:
However, if a person has already had symptoms of cardiovascular disease, such as angina pectoris or a myocardial infarction, or had an angioplasty or by-pass operation in their coronary arteries, they should receive medical treatment to maintain their level Of LDL cholesterol below 100 mg / dL.
- Ideal level: less than 200 mg / dL
- Cholesterol slightly elevated: between 200 and 240 mg / dL
- Moderately elevated cholesterol: between 240 and 300 mg / dL
- Very high cholesterol: above 300 mg / dL.
- Cholesterol Levels
- In general, the following values are supported for cholesterol levels (mg / dl):
- Ideal: less than 200
- Slightly high: between 200 and 240
- Height: between 240 and 300
- Very high: more than 300
What causes cholesterol elevation?
In cholesterol levels, there are very different factors: race, geographical origin, diet, lifestyle, etc., and in the countries of southern Europe, such as Spain, average cholesterol levels are lower than those in the north or the United States.
The main factor, however, is genetic influence or inheritance. This is why there are several people with high cholesterol in the same family. There is a hereditary form that produces slight elevations of levels, but when there are many relatives with very high cholesterol, serious metabolic disease, such as familial hypercholesterolemia (HF) or combined familial hyperlipidemia (HFC), should be suspected. Triglycerides are also elevated. In some cases, cholesterol is high as a result of other diseases, such as thyroid hormone defect, kidney disease or diabetes. A very common cause of triglyceride elevation is excessive ingestion of alcohol.
What symptoms does cholesterol raise?
Most people with high cholesterol do not have any symptoms or alterations to suspect. In some cases cholesterol deposits can be seen in the eyes, skin and tendons. As mentioned above, the true importance of hypercholesterolemia is that, along with other risk factors, it favors the premature development of atherosclerosis and cardiovascular diseases.
Atherosclerosis is a slow process so that, over the years, fat and cholesterol are deposited on the walls of the arteries (atherosclerotic plaques). As a result, their hardening and narrowing occurs, which reduces the amount of blood that can pass through them and decreases the irrigation necessary for different organs. Over time, the artery can become obstructed and thus cause a heart attack in areas that depend on your blood supply (resulting in the death of those tissues).
Therefore, when symptoms appear, they are a consequence of arterial disease. These depend on the degree of obstruction and the organ supplied by the affected arteries. An added problem is the possibility of plaques breaking, resulting in a blood clot (thrombus) that abruptly and totally obstructs the artery.
It is very common for people with arteriosclerosis to have affected the arteries of different places or organs at the same time. In addition to those already mentioned, the large aorta artery (which leaves the heart and distributes blood to the rest of the body), the arteries of the kidney and the arteries of the intestine (mesenteric arteries) tend to become diseased.
In the brain, an arterial branch can be obstructed by a thrombus, leaving a zone of the brain without blood supply, resulting in a cerebral infarction. At other times, the artery may rupture and cause bleeding. Either of these two conditions can produce similar symptoms and are called stroke or stroke (stroke). It may also happen that small clots form in the arteries of the neck and that on reaching the brain obstruct for a short time a small vascular branch (transient ischemic attack or TIA). However, when the latter are repeated, one must fear the possibility of a cerebral infarction.
In the heart, narrowing of the coronary arteries causes angina pectoris, and rupture of a fat plaque (atheroma) causes coronary thrombosis that results in a myocardial infarction. If a significant amount of cardiac tissue is damaged, there may be a reduction in the heart’s ability to pump blood (heart failure).
Partial obstruction of the arteries of the legs produce a typical pain when walking that disappears when stopped and is known as intermittent claudication. If a complete or very rapid obstruction of one of the arteries occurs, lack of irrigation leads to the death of all tissues (acute ischemia), which forces limb amputation.
All studies clearly show that middle-aged men and women who smoke have a much higher risk of having a myocardial infarction. When quitting smoking, this risk decreases progressively.
Food is another important factor and its potential benefits are greater than the variations in cholesterol levels indicate. It is recommended to maintain a Mediterranean diet rich in bread, pulses, fruits, vegetables, blue fish and olive oil, as well as to limit the consumption of whole dairy products (non-skimmed), meats and products with a high content of harmful fats.
Its very moderate consumption, especially of wine, increases HDL cholesterol and may reduce the negative effect of LDL cholesterol. However, it produces both an increase in blood pressure and can damage the liver and other organs.
It is very beneficial even if it is not too intense, and has been shown to reduce the risk of coronary heart disease. Vigorous and regular physical exercise favors the elimination of clots.
Excessive body weight
Obesity and overweight, especially when fat is concentrated in the abdomen, favor the onset of cardiovascular disease. It is beneficial to lose, even lightly, that excess weight.
What can be done to prevent vascular disease?
Atherosclerosis (with its complications) is a complex disease, which does not have a single origin. The elevated cholesterol level, although it is one of the most important risk factors, does not usually determine its occurrence by itself. The usual is that several factors coincide, which produces a marked increase in risk. For this reason, it is essential that the greatest number of them be recognized and corrected.
How does the doctor make the diagnosis?
A blood sample is analyzed after a fasting period of at least 12 hours (only water can be taken) to measure the level of total cholesterol, LDL and HDL cholesterol, and triglycerides. To avoid errors it is necessary to know that some medications and pregnancy produce elevations of cholesterol and, on the contrary, a transient decrease is observed during many diseases, such as a myocardial infarction.
In some patients with severe hypercholesterolemia of hereditary origin the external cholesterol deposits mentioned above can be found. Whenever high cholesterol is found, the doctor should look for possible symptoms of cardiovascular disease, measuring blood pressure and auscultation of the heart and checking the arterial pulses (measurement of tension). It is also convenient to measure blood glucose, assess renal function and perform an electrocardiogram (ECG).
When should high cholesterol be treated with medications?
The first steps to treat hypercholesterolemia are a proper diet (lipid-lowering), reduce excess weight and exercise regularly. When these changes in diet and lifestyle are not possible or have not achieved a sufficient reduction of cholesterol level, treatment with medication should be considered, if necessary.
This decision depends on the overall cardiovascular risk due to the presence or absence of other factors, or if there are already symptoms of cardiovascular disease. According to the case of each person a specific number of total cholesterol and LDL is chosen from which they must be treated with drugs and set goals to be achieved. In any case, it is important to know that when a drug treatment is really needed, it is usually forever.
The most effective cholesterol-lowering medications today are so-called statins, which, while expensive, have relatively few side effects. Fibers and powders can also be used with resins.