Atherosclerosis

Atherosclerosis is tarts when the endothelium becomes damaged, allowing low-density lipoproteins (LDL – bad) cholesterol to accumulate in the artery wall. It’s the usual cause of heart attacks, strokes, and peripheral vascular disease — what together are called cardiovascular disease.

Causes of atherosclerosis:
Atherosclerosis begins with damage to the endothelium. That damage leads to the formation of plaque. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood.

When bad cholesterol (LDL), crosses the damaged endothelium, the cholesterol enters the wall of the artery. That causes the white blood cells to stream in to digest the LDL. Over years, cholesterol and cells become plaque in the wall of the artery.

Certain factors can damage the inner area of the artery (endothelium) and can trigger atherosclerosis; these factors include:

•  hypertension (high blood pressure)
• high levels of cholesterol
• smoking
• high levels of sugar in the blood

Certain people have a higher risk of developing the condition:

• Diabetes – patients with poorly controlled diabetes, who frequently have high blood glucose levels, are more likely to develop atherosclerosis.
• Genetics – people with a parent or sibling who has/had atherosclerosis and cardiovascular disease have a much higher risk of developing atherosclerosis than others.
• Air pollution – exposure to air pollution appears to increase the risk of cholesterol build-up in the coronary arteries.

Symptoms of atherosclerosis:

The first signs of atherosclerosis can begin to develop during adolescence, with streaks of white blood cells appearing on the artery wall. Most often, there are no symptoms until a plaque ruptures or the blood flow is very restricted, which typically takes many years to occur.

The symptoms depend on which arteries are affected:

Carotid arteries: Carotid arteries provide blood to the brain; when the blood supply is limited, patients can suffer stroke and may experience: weakness, difficulty breathing, headache, facial numbness, paralysis.

Coronary arteries: Chest pain can be a symptom of atherosclerosis affecting the coronary arteries Coronary arteries provide blood to the heart; when the blood supply to the heart is limited, it can cause angina and heart attack; symptoms include: vomiting, chest pain, extreme anxiety, coughing, feeling faint.

Renal arteries: Renal arteries supply blood to the kidneys; if the blood supply becomes limited, there is a serious risk of developing chronic kidney disease, and the patient may experience: loss of appetite, swelling of the hands and feet, difficulty concentrating

Peripheral arterial disease: In peripheral arterial disease, the arteries to the limbs (most commonly the legs) are blocked. The most common symptom is leg pain, either in one or both legs, usually in the calves, thighs, or hips.
The pain may be described as one of heaviness, cramp, or dullness in the leg muscles. Other symptoms can include: hair loss on legs or feet, male impotence (erectile dysfunction), numbness in the legs, the color of the skin on the legs change, the toenails get thicker, weakness in the legs.

Diagnosing atherosclerosis:
Those who are at risk of developing atherosclerosis should be tested because the symptoms don’t show until cardiovascular disease develops. A diagnosis will be based on the medical history of a patient, test results, and a physical exam.

Blood tests – these measure how much sugar, fat, and protein there is in the blood. If there are high levels of fat and sugar, it could indicate an increased risk of atherosclerosis.

Physical exam-

• The doctor will listen to the arteries using a stethoscope to see if there is an unusual “whooshing” due to uneven blood flow – called a bruit. If a bruit is heard, it can mean there is plaque obstructing blood flow.
• There may also be a very weak pulse below the area of the artery that has narrowed. Sometimes, there is no detectable pulse.
• An affected limb may have abnormally low blood pressure.
• There may be signs of an aneurysm (pulsating bulge) behind the patient’s knee or in their abdomen.
• Where blood flow is restricted, wounds may not heal properly.

Ultrasound – an ultrasound scanner can check blood pressure at distinct parts of the body; changes in pressure indicate where arteries may have obstruction of blood flow.

Computed tomography (CT) scan – CT scan can be used to find arteries that are hardened and narrowed.

Treatments for atherosclerosis:

Those who are at risk of developing atherosclerosis will likely be told by their doctor to change their lifestyle and maintain a healthy weight. In some cases, treatment may include medication or surgery.

Lifestyle Changes – The changes will focus on weight management, physical activity, and a healthy diet. A doctor may recommend eating foods high in soluble fiber and limiting intake of saturated fats, sodium (salt), and alcohol.

Medication – some medications can prevent the buildup of plaque or help prevent blood clots (antiplatelet). Other medications, such as statins, might be prescribed to lower cholesterol and Angiotensin-converting enzyme (ACE) inhibitors to lower blood pressure.

Surgery – Severe cases of atherosclerosis may be treated by surgical procedures, such as angioplasty or coronary artery bypass grafting (CABG).Angioplasty involves expanding the artery and opening the blockage so that the blood can flow through properly again. CABG is another form of surgery that can improve blood flow to the heart by using arteries from other parts of the body to bypass a narrowed coronary artery.

Prevention of atherosclerosis:

Diet – Try to avoid saturated fats, they increase levels of bad cholesterol. The following foods are high in unsaturated fats and can help keep bad cholesterol levels down- olive oil, avocados, walnuts, oily fish, nuts, seeds.
Exercise – exercise will improve fitness levels and lower blood pressure; it will also help weight loss.
Smoking – this is one of the major risk factors for atherosclerosis, it also raises blood pressure. Smokers should quit as soon as possible and arrange a meeting with their doctor about ways to give up and manage withdrawal symptoms.

By – Assistant Professor – Mrs Anita Mehar
Biochemistry Department
Uttaranchal (P.G.) College Of Bio-Medical Sciences & Hospital