ARTERIOSCLEROSIS / ATHEROSCLEROSIS
Arteriosclerosis and atherosclerosis are widely and often interchangeably used terms, yet in all probability, few people have a precise understanding of what these words refer to. Arteriosclerosis is, in fact, the most significant element in the development of cardiovascular diseases, which as a group represent the leading cause of death and disability in the world.
The cardiovascular system pumps blood to the entire body. The heart (specifically, the left ventricle) is the "pump" that performs this function, sending blood through the body's system of arteries (the system begins at the aorta, which later spawns various different arterial branches, which in turn spawn many more branches) to all parts of the body. Arteriosclerosis debilitates the arterial system, leading to a substantial decrease in blood flow and, on occasion, blocking some arterial branches.
Contrary to common belief, this process does not begin at advanced ages; in fact, it begins at very early ages. Autopsies of young car accident victims and soldiers have revealed evidence of the onset of heart disease in the arteries.
To understand how arteriosclerosis occurs, it's necessary to understand that the arteries are coated internally with a layer called endothelium, which is the part of the artery that comes into contact with circulating blood. Through a series of factors (which we will analyze later), plaque (called atheroma) begins to form in the area underlying the endothelium; fatty substances accumulate and are trapped by cell matter, and then acquire a foamy texture, and have the appearance of fatty streaks. If this process continues the plaque continues to increase in size, covering over with a fibrous layer and forming in its interior a nucleus consisting mainly of fatty substances and inflammatory cells. The more plaque grows, the smaller the space becomes within the artery, which considerably decreases blood flow. As it grows, plaque can become ulcerated and break the fibrous layer that covers it; when this happens, coagulation occurs, further obstructing the interior of the already-narrowed artery, which can lead to various symptoms (depending on which organ is receiving blood from the affected artery).
The appearance and progress of atherosclerotic diseases are influenced by risk factors, which can be classified as nonmodifiable or modifiable. Nonmodifiable risk factors include age: risk increase with age; sex: men have higher risk than women at younger ages, while women's risk increases after menopause; and family history: having blood relatives with a history of these diseases raises your probability of having them, too.
Modifiable risk factors are extremely important, because the amount by which we reduce them determines how much we limit the progression of cardiovascular diseases. Smoking is one of the most notable modifiable risk factors: according to the World Health Organization, smoking and secondhand smoke exposure represent the world's leading cause of death. Other modifiable risk factors are blood lipid disorders: total cholesterol, elevated LDL-cholesterol and/or triglycerides; low HDL-cholesterol, etc.; overweight and obesity; physical inactivity; hypertension; diabetes; stress and another factor that in recent years has been shown to have an important role in the onset and progression of these diseases, psychosocial factors.
Given the information presented above, it is easy to conclude that to avoid atherosclerotic disease, we should begin taking preventive steps during childhood. We should encourage children to develop healthy lifestyle habits that they will maintain through adulthood, including healthy diet, weight control, physical activity, avoiding smoking, maintaining healthy blood pressure levels and optimal levels of blood glucose, cholesterol and triglycerides.
Finally, we must note that cardiovascular risk factor modification has been shown to effectively reduce, halt or even reverse atherosclerotic disease.
Dr. Italo Torchio
Córdoba - Argentina
Consejo de Epidemiología y Prevención Cardiovascular
Sociedad Argentina de Cardiología