What is atherosclerosis?
Atherosclerosis is characterised by the buildup of plaque in an artery. This plaque is composed mostly of fat, cholesterol, and calcium. It can cause a restriction or complete blockage of blood flow. When it happens in the coronary arteries it leads to heart attack or stroke when the cerebral arteries are affected. Atherosclerosis is directly connected with damage to the inner lining of the arteries, the endothelium made of the endothelial cells. When these cells are damaged, inflammation arises in the internal layer of the vessel and causes the development of the plaque [1, 2].
What is arteriosclerosis?
Arteriosclerosis is a more general term. It refers to the stiffening and hardening of the wall of arteries. It is a condition that affects mostly older people and is caused by the gradual loss of elasticity of the arteries. The change in the arterial wall increases the risk of hypertension and other health conditions. [1, 3].
Causes and risk factors of atherosclerosis and arteriosclerosis
The cause of atherosclerosis is primarily damage of the internal lining of the arteries. This damage and, caused by it, inflammation both promote the development of the plaque. The crucial part in this process is played by cholesterol. It is the main component of the plaque and plays a crucial role. High cholesterol accumulation and its oxidation during the inflammatory process increase the size of the plaque. The growing plaque extends into the lumen of the artery, causing restriction or even complete obstruction of blood supply to vital organs [1].
Risk factors are those that cause damage to the lining leading to the plaque. They include smoking, high blood cholesterol, hypertension, age, high blood sugar (hyperglycaemia), and genetic factors. Additionally, certain infections, such as influenza, herpes, hepatitis viruses, or papillomaviruses, have been positively linked to the development of atherosclerosis [4].
Arteriosclerosis is caused by stiff and hard walls of the arteries. This impedes the pressure regulation of the organism at the artery level and increases the blood pressure. This process is initiated by long-term hyperglycaemia, which is why it mostly affects older people. The prolonged exposure to glucose leads to the glycation of collagen and elastin by glucose and its metabolites, allowing them to interconnect by forming cross-links between fibres. Also, simply with age, the arteries become stiffer and harder on their own. [1, 5].
Risk factors for arteriosclerosis include prolonged overnutrition, nicotine abuse, lack of physical exercise, muscular overstrain, emotional stress, and concomitant diseases like arterial hypertension, diabetes mellitus, and dyslipidaemia [6].
In arteriosclerosis as well as atherosclerosis, unhealthy nutrition, sedative lifestyle, overweight, and smoking have been identified as primary causes [7].
Symptoms of atherosclerosis and arteriosclerosis
Atherosclerosis is responsible for myocardial infarctions and strokes. In the first case, the main symptom is chest pain or angina, which, depending on the type (stable angina or unstable angina), can appear during physical or emotional stress (unstable angina) or continuously, regardless of the situation or activity (stable angina) This chest pain occurs due to an insufficient blood supply to a part of the heart [1].
Shortness of breath is often an accompanying symptom of atherosclerosis, as are nausea and general weakness [1]. However, in some atypical cases, they can present without chest pain. Aside from these most common symptoms, cold sweats, dizziness, fatigue, or a fast heart rate (tachycardia) can also occur [1]. Also, some people may experience cramping, especially in the buttocks, while walking [1, 8].
In cases where the blockage is in the brain arteries, brain circulation is affected, causing a stroke [1, 8]. Depending on the location and size of the affected artery, the symptoms of the stroke include confusion, muscle weakness or paralysis, and abrupt speech problems [1, 8]. More specifically, a stroke in the basal ganglia may cause movement disorders such as hemiballism or dystonia.
Arteriosclerosis, on the other hand, often causes no symptoms. Especially in the early stages, even if it progresses into hypertension, it can cause no symptoms. However, with a significant high blood pressure, symptoms can include chest pain, headaches, or blurred vision [1, 9].
Diagnosis of atherosclerosis and diagnosis of arteriosclerosis
Blood pressure measurement is a key diagnostic tool, especially for arteriosclerosis. High blood pressure can be an indication of the development of arteriosclerosis or a risk factor for atherosclerosis [1]. In atherosclerosis biochemistry of the blood is performed to confirm the presence of bad cholesterol, or another risk factor like diabetes [1].
Imaging techniques are also used in the diagnostic process. For instance, transoesophageal echocardiography (TEE) can be used to diagnose aortic atherosclerosis. Its presence is associated with an increased risk for recurrent ischemic stroke and cardiovascular death [10]. 75.9% of patients with coronary artery disease (CAD) had aortic atherosclerosis detected by TEE [10].
Non-invasive methods such as echography and tomodensitometry can be used in suspicion of asymptomatic atherosclerotic lesions in a coronary artery, carotid artery, aorta, and renal arteries [11]. However, in cases of suspected CAD coronary angiography remains the gold standard [11].
To confirm an arteriosclerosis the B-mode sonography is a reliable method, with an impressive specificity of 100%. Its only backdrop is that its sensitivity in detecting different arteriosclerotic lesions is 85% [12].
Treatment of atherosclerosis vs arteriosclerosis
For atherosclerosis, which is a chronic inflammatory disease, affecting medium and large arteries, the primary approach is to stabilise the disease by reducing low-density lipoprotein cholesterol levels using statins. Also, raising atheroprotective high-density lipoprotein (HDL) and/or improving HDL function is part of the treatment strategy [13]. Other treatments target inflammatory cells, particularly the T cells, to slow down the atherosclerosis process [14].
On the other hand, arteriosclerosis, the condition where the artery walls become stiff and hard, is treated first by cessation of risk factors like smoking. A regime of healthy diet and exercise is introduced to stop the progress of the diseases. In severe cases, pharmacologic therapy, balloon angioplasty and stenting of vessels, or bypass surgery, and therapeutic angiogenesis are used [15]. The pharmacological treatment includes antiplatelet agents and anticoagulants, with anticoagulation with heparin or low-molecular-weight heparin being effective in reducing cardiovascular events by approximately 50% [16].
A common part of the treatment are healthy lifestyle habits. They include physical activity, with a recommendation of 90 to 150 minutes of exercise per week, and eating heart-healthy. Recommended is a food rich in monounsaturated fats, fruits, vegetables, and fibre, and low in salt, according to WHO lower than 5g a day, and saturated fat [1, 17]. An important step is cessation of smoking and restriction of alcohol. Lifestyle changes include good stress management and sleep (7 to 9 hours each night) [1].
In some cases, autologous adipose-derived mesenchymal stem cells (Ad-MSC) administration has been used for the treatment of arteriosclerosis. It showed significant improvements in lipid profile [18].