What Is the Main Cause of Arteriosclerosis?

Arteriosclerosis is the thickening of small size arteries caused by an injury of the artery wall, aging, hypertension, or diabetes [1].

The hardening of small size arteries is due to a process known as intimal hyperplasia that is caused by the following lesions:

• The presence of vascular smooth muscle cells between the endothelium (layer of endothelial cells) and the internal elastic lamina.
• Deposition of hyalin between the endothelium and the internal elastic lamina.

A small or medium-sized artery is composed inside out from the following structures:

• A layer of endothelial cells that form the internal lining of the artery and are in contact with the circulation blood. It is also known as intima.
• An internal elastic structure known as internal lamina that surround the endothelial cells.
• A layer of smooth muscle cells that sits on the top of the internal lamina and known as tunica media or media.
• An external elastic structure known as external lamina.
• A layer of fibroblast cells known as adventitia.

1. What Is the Difference Between Arteriosclerosis and Atherosclerosis?

Arteriosclerosis is the general term that is used to classify 3 types of artery lesions [2]:

• Atherosclerosis
• Mönckeberg’s medial calcific sclerosis
• Arteriosclerosis

Atherosclerosis and Mönckeberg’s medial calcific sclerosis are pathologic lesions, while arteriosclerosis can be pathologic or natural (e.g. aging) [3].

• What Is Atherosclerosis?

Atherosclerosis is a disease of elastic and large arteries caused by the formation of atheroma. It is considered a chronic inflammatory as inflammation is involved in the process of atherosclerosis [4].

An atheroma is made of macrophages (type of immune cells), fibrous connective tissue, lipids, and calcium.

• What Is Mönckeberg’s Medial Calcific Sclerosis?

Mönckeberg’s medial calcific sclerosis is a calcification disease of the arteries associated with idiopathic (unknown cause), renal failure, or type II diabetes [4].

• What Is Arteriosclerosis?

Arteriosclerosis is the hardening of small and medium-size arteries caused by intimal hyperplasia due to an injury of the artery wall, aging, and inflammation [1].

2. What Are the Warning Signs of Arteriosclerosis?

Arteriosclerosis and atherosclerosis can limit the blood flow to the brain and affect the function of the arteries which cause the following signs:

• Sudden weakness
• Confusion
• Facial or lower limb numbness
• Difficulty understanding speech
• Vision problems
• Chest pain
• Dizziness
• Palpitations
• Shortness of breath

These signs or symptoms are due to the low supply of oxygen and nutrients to the brain causing ischemia or stroke that leads to brain damage, while this low supply affects the function of the arteries leading to a heart attack associated with acute myocardial ischemia.

Ischemia is a low blood supply to any type of tissue, while a stroke is in the absence of blood supply to the brain.

3. How Is Arteriosclerosis Diagnosed?

Following the appearance of signs that suggest potential arteriosclerosis or atherosclerosis, and physical examination, the diagnosis may involve the following examinations:

• Blood tests to check the blood levels of sugar and cholesterol.
• Electrocardiography to evaluate the heart electric signals.
• Exercise stress test.
• Echocardiogram.
• Cardiac catheterization angiogram to check the potential thickening or blockage of the arteries.
• Heart scan using CT (computerized Tomography) imaging of the heart.
• Doppler ultrasound to measure the blood pressure along the arms and legs.
• Ankle-brachial index to check the potential presence of atherosclerosis in the arteries of legs and feet.

4. What Are the Risk Factors of Atherosclerosis?

Atherosclerosis is associated with the following risk factors [2]:

• Aging
• Gender
• Family History
• Hypertension
• Smoking
• Obesity
• Type II Diabetes (mellitus)
• Unhealthy Diet/Lipid level
• Gout
• Emotional Stress
• Hypothyroidism
• Inactivity
• Type A Personality
• Fibrinogen Level
• Sleep apnea

5. What Are the Stages of Atherosclerosis?

There are 5 stages in the formation of an atheroma:

Stage 1

The first stage is associated with the injury of the endothelium that can be caused by hypertension, hyperlipidemia (excess of lipid in the blood), toxins, smoking, homocysteine, viruses, inflammation, and hemodynamic factors.

Stage 2

The injury of the endothelium results in alterations of its function that manifest by increased permeability, leukocyte adhesion, and monocytes adhesion and emigration.

Stage 3

Emigration of the muscle smooth cells from the media to the intima results in the activation of macrophages.

Stage 4

Muscle smooth cells and macrophages engulf low-density lipoprotein-cholesterol (LDL-C) forming foamy cells which lead to the formation of fatty streaks.

Stage 5

The final step is the completion of the formation of an atheroma that is made of proliferating (increased cell division) muscle smooth cells, deposited collagen, and other compounds of the extracellular matrix (space surrounding cells), lymphocytes, and foamy cells.

6. How to Prevent Atherosclerosis?

The risk of atherosclerosis can be reduced by making lifestyle changes such as:

• Avoiding or stopping smoking
• Consumption of a healthy diet that contains less sugar and cholesterol
• Losing weight
• Regular exercise
• Maintaining a healthy blood pressure
• Reducing stress
• Treating sleep apnea

7. Can Arteriosclerosis Be Cured?

The prevention of atherosclerosis is the first line of treatment; however, some cases require medications or surgery [5].

• Medications

Medications are aimed at significantly reducing the level of low-density lipoprotein (LDL) cholesterol using statins and cholesterol medications.

To prevent a further potential narrowing of the arteries, blood thinners may be used to stop the formation of blood clots on top of the atheroma.

To prevent any potential complications associated with atherosclerosis, blood pressure medications may also be used.

• Surgery

Surgery may be indicated if the atherosclerosis is becoming severe with a high risk of ischemia that can result in the loss of arteries tissues.

Coronary Angioplasty and Stenting

This procedure involves introducing a catheter with an inflated balloon that is inflated afterward to open the blocked artery. This step of the surgery is followed by the introduction of a mesh tube (stent) to keep it open after the surgery.

Coronary Artery Bypass Grafting (CABG)

Arteries or veins from other parts of the body are used to bypass the part of the artery with atherosclerosis which allows the blood to flow around the blocked part of the artery.

Carotid Endarterectomy

This procedure removes the artery plaque from within the carotid arteries (neck region) to deblock blood flow to the brain.

Conclusion

Arteriosclerosis and atherosclerosis can lead to significant damages to the brain and arteries resulting in stroke and acute myocardial ischemia. Most of the causes of these diseases are associated with lifestyles such as unhealthy diet, lack of exercise, obesity, stress, and smoking. Therefore, making lifestyles changes can significantly reduce the risk of arteriosclerosis and atherosclerosis.