What is cholesterol?
What is cholesterol? Cholesterol is one of the most important lipids or fats in the body. Cholesterol is essentially used in the formation of cell membranes in our organs and as a “raw material” for the synthesis of sex hormones and adrenal-derived hormones.
Under normal conditions, almost all of the cholesterol in the body comes from what we absorb from food and what the liver can produce. This cholesterol passes through the bloodstream, carried by specially designed proteins called lipoproteins, and is distributed to various devices and systems in the body.
When too much cholesterol circulates in the blood, it tends to settle on the walls of the arteries, causing what is called “arterial plaque”. Arterial plaque consists mainly of cells that phagocytose cholesterol, where it is stored: macrophages, muscle cells reach these lesions, where they synthesize substances that cause fibrosis and changes in the plaque.
The high cholesterol level in the blood perpetuates this process. The plaques increase in size, contributing to the stiffening and progressive occlusion of the blood vessels. Occasionally, the plaque may rupture and form a clot that completely or partially blocks the artery.
This rupture and clot can release emboli that would otherwise circulate in the bloodstream, affecting smaller arteries and preventing perfusion of the tissues that depend on those arteries.
All these phenomena cause a disease called atherosclerosis, which, depending on the location of the affected artery, causes various cardiovascular diseases that we call ischemic heart disease: angina pectoris or acute myocardial infarction, stroke: heart attack or cerebral thrombosis, and peripheral arterial disease: lower extremity ischemia, aortic aneurysm or intestinal ischemia.
Yes, but in a nuanced way. If cholesterol is a special principle, then, as mentioned above, it is carried into the blood by lipoproteins. Basically, two types of lipoproteins are responsible for this transport: low-density lipoprotein or LDL (low-density lipoprotein) and high-density lipoprotein or HDL (high-density lipoprotein). The former is responsible for transporting cholesterol into the tissues, an excess of which is associated with the development of atherosclerosis; HDL extracts excess cholesterol from atheroma cells and plaques.
In addition to total cholesterol, laboratories measure cholesterol associated with two types of lipoproteins: LDL cholesterol and HDL cholesterol. These correspond to what is commonly known as “bad” or “good” cholesterol because it increases or decreases atherosclerotic plaque.
The more cholesterol you have, the more heart attacks you will have. Several epidemiological studies have shown that cardiovascular processes increase when total cholesterol levels in the blood exceed 200 mg/dl. This level should be lower if other concomitant risk factors and cardiovascular diseases are present. For this reason, it is guided by LDL (bad) cholesterol levels.
For very high-risk patients who are considered to be type 2 diabetics, or who already have cardiovascular disease, or have a calculated risk of dying from the cardiovascular disease at 10% or more within 10 years, cholesterol levels should be targeted at a CLDL of less than 70 mg/dl.
For those at high risk (5-10%), the maximum level should be 100mg/dl and for those at intermediate risk (1-5%), and the CLDL level should not exceed 115mg/dl.
Talk to your doctor. Your doctor will guide you through the possible causes of this elevated level and initiate an appropriate diet (which may be supplemented with medication).
He or she will also determine if you should be referred to the lipid unit, depending on the number of problems and the need for an accurate diagnosis. In the next article, we will discuss how diet and exercise can affect cholesterol levels.