The truth about cholesterol and lipids

Perhaps it is difficult to find a person today who would not know that cholesterol is one of the culprits in the development of heart attack, stroke and many other serious vascular problems that are based on atherosclerosis. And it is no secret that these diseases have become much younger in recent decades. And if earlier heart attack and stroke were the lot of the elderly, nowadays these complications of atherosclerosis are observed even in 30-year-olds. However, who of us knows our blood cholesterol level? As a rule, very few.

In this regard, we would like to draw your attention to the importance of such a laboratory test as cholesterol determination, or, to be more precise, the study of the entire lipid metabolism.

For any American, the question, "What is your cholesterol?" Moreover, a normal cholesterol reading is not only a source of joy, but also a well-deserved source of pride for the host. Why? Let's try to understand it.

Cholesterol, a fat-like substance, is the main substrate of atherosclerotic plaque and the main culprit in the development of atherosclerosis, a disease of human arteries.

Cholesterol in itself is not harmful. The blood must necessarily contain a certain amount of fats and cholesterol. The role of cholesterol in the human body is extremely great. It is part of cell membranes and is also necessary for the synthesis of steroid hormones (adrenal cortex hormones, sex hormones). Vitamin D is also formed from cholesterol. Cholesterol can come from food (animal fats, eggs) or be synthesised in the body (in the liver and intestines). Normal serum cholesterol levels are 3.7-5.2 mmol/l (160-200 mg/dl). Cholesterol levels are characterised by seasonal fluctuations: the highest levels are found in winter and the lowest in summer. Apparently, these differences are due to changing dietary and lifestyle habits depending on the time of year. Excess cholesterol is dangerous. When the level of cholesterol in the blood exceeds a certain value, it begins to deposit in the form of plaques on the walls of the arteries and narrows their lumen.

But to assess the true risk of vascular disease, knowledge of total blood cholesterol levels is not enough. A person may have relatively high blood cholesterol but a fairly minimal risk of coronary heart disease. Conversely, a relatively low cholesterol content may be characterised by a relatively high risk of coronary heart disease. This is explained by the fact that lipids themselves, including cholesterol, do not dissolve in the blood, but they are transported through the arteries by joining with special proteins - lipoproteins.

Therefore, when determining the individual risk of atherosclerosis, it is important to know the entire lipid spectrum of the body, which in addition to cholesterol is represented by triglycerides, high, low and very low density lipoproteins. Triglycerides are an important source of energy for muscles. They are composed of fatty acids, which can be saturated and unsaturated. Saturated fatty acids are found in animal fats (butter, lard) and unsaturated fatty acids in vegetable fats (sunflower, olive, corn oil). Saturated fatty acids can be obtained from food and synthesised in the liver, unsaturated fatty acids cannot be formed in the body, therefore they are essential and must be obtained from food. Normal triglyceride levels are 0.5-1.5 mmol/l (up to 130 mg/dl). Triglyceride levels may increase in obesity, diabetes mellitus, chronic renal failure, alcoholism, pregnancy, and certain medications.

Lipoproteins are proteins that transport cholesterol and triglycerides in a bound form. Of most interest to the clinician are high-density lipoproteins (HDL), low-density lipoproteins (LDL) and very low-density lipoproteins (VLDL). HDL HDL are small in size, contain a lot of protein and are therefore tough. When they penetrate the vessel wall, they capture cholesterol and carry it to the liver. In this way, HDLs prevent the development of atherosclerosis. HDL level of more than 50 mg/dl in men and more than 60 mg/dl in women is considered normal. HDL are small in size, contain a lot of protein and are therefore tough. When they penetrate the vessel wall, they capture cholesterol and carry it to the liver. In this way, HDLs prevent the development of atherosclerosis. An HDL level of more than 50 mg/dl in men and more than 60 mg/dl in women is considered normal. People with this level of HDL have a low risk of atherosclerosis. A high risk of atherosclerosis occurs when HDL levels are low: less than 35 mg/dl in men and less than 45 mg/dl in women. LDL and VLDL carry mainly cholesterol. Therefore, their content increases when cholesterol levels rise. LDL contains a lot of triglycerides. LDL and VLDL are low in protein, large and loose. When they penetrate the vessel wall, they "fall apart", so it becomes saturated with cholesterol and triglycerides. An increase in the blood level of LDL and LDLNP leads to the early development of atherosclerosis. Indirectly about the level of HDL can be judged by the coefficient of atherogenicity (CA). The lower it is, the more HDL in the blood.

If the patient is found to have a lipid metabolism disorder, the doctor will recommend him to follow a special diet containing a reduced amount of fats of animal origin (i.e. reduce the consumption of fatty meat, butter, cheese, eggs, kidneys), as well as easily digestible carbohydrates (sugar, chocolate, candy, white flour products). The diet of such patients should include foods with a high fibre content - vegetables and fruits, with the exception of potatoes, bananas, grapes. Seafood is useful. If dietary intake fails to normalise cholesterol levels, the doctor may additionally prescribe special cholesterol-lowering drugs.

Who makes the referral for the test?

Blood tests for lipid metabolism can be prescribed by a doctor of any speciality. Most often it is done by a cardiologist and neurologist, because an increase in lipid levels leads to increased frequency of angina attacks and increased risk of myocardial infarction and stroke.

Blood for the test is taken from the vein on an empty stomach, usually in the morning at 8-9 o'clock. In order for the results of the test to be reliable, it is necessary to prepare for it properly. The patient can have dinner no later than 19 hours. It is desirable that the dinner was light - a small piece of fish or lean meat with a vegetable side dish or mashed potatoes. You can eat porridge or low-fat cottage cheese. If you are very hungry, you can drink a glass of kefir before going to bed.