Arteriosclerosis

Atherosclerosis, often referred to as “hardening of the arteries,” is a chronic inflammatory condition of the body’s arteries in which plaques (fatty deposits) build up inside the arterial wall. These plaques consist mainly of cholesterol, lipids, cellular waste products, calcium, and fibrin (a protein involved in blood clot formation)¹.

The disease develops gradually over a lifetime and rarely causes symptoms until the arteries are significantly narrowed or blocked. Atherosclerosis is considered the leading cause of cardiovascular disease and accounts for approximately half of all deaths in Western societies¹.

Causes and etiology

Atherosclerotic vascular disease has a complex, multifactorial origin in which lifestyle, environmental, and genetic factors all play a role. The most important risk factors include:

• Elevated blood cholesterol levels, especially LDL cholesterol (low-density lipoprotein)

• High blood pressure (hypertension)

• Diabetes

• Smoking

• Overweight

• Lack of physical activity

• Unhealthy diet, especially high intake of saturated fats and trans fats

• Older age (men over 45 years, women over 55 years are at higher risk)

• Male sex

• Family history (male relative <55 years, female relative <65 years with early disease)

• Certain genetic disorders (e.g., familial hypercholesterolemia, where LDL receptors are defective and cause very high cholesterol)²

Genetic factors are receiving increasing attention. Studies show that heredity can account for 38–57% of cases of early myocardial infarction². Gene variants may influence blood lipid levels, inflammatory processes, and the tendency for calcification in arteries. Mutations in certain genes can trigger inflammatory responses or calcium deposition, both of which promote the development of atherosclerosis.

Epidemiology

Atherosclerosis develops over many years and often produces no symptoms until arteries become severely narrowed or blocked. It is the main cause of the most common cardiovascular diseases, including myocardial infarction, angina, stroke, and peripheral artery disease. Cardiovascular diseases are the leading cause of death worldwide, with coronary artery disease and ischemic stroke being the most frequent manifestations³.

The prevalence of atherosclerosis increases with age, and the disease affects more men than women, particularly in younger and middle-aged groups. Because the condition is often asymptomatic, the exact prevalence is difficult to determine, but population studies show that many people already have signs of early atherosclerosis in their 30s and 40s³.

Pathophysiology

Atherosclerosis develops when lipids, particularly LDL cholesterol, are deposited in the innermost layer (intima) of the arterial wall. These lipids are bound by supporting tissue (matrix, mainly proteoglycans) and attract inflammatory cells such as macrophages and T-lymphocytes. Inflammatory processes amplify damage to the vessel wall, leading to further deposition, cell growth, and the formation of a plaque.

The disease progresses through several stages:

1. Fatty streak

   This initial stage can be observed even in children. Yellow streaks of fat, mainly cholesterol and macrophages, form along large arteries such as the aorta and carotid arteries. This stage causes no symptoms but represents the foundation for further disease development⁴.

2. Fibrous plaque

   Over time, the fatty structure enlarges, more cells and connective tissue are recruited, and a firm, fibrous plaque forms in the arterial wall. The plaque protrudes into the vessel lumen, narrowing the artery. This can reduce blood flow, particularly during times of increased cardiac demand⁴.

3. Complicated lesion

   If the fibrous plaque ruptures, the underlying tissue and lipids are exposed to the bloodstream. The body responds as if to an injury: platelets are activated and a thrombus (blood clot) forms at the narrowed site. This can result in complete arterial blockage and lead to acute myocardial infarction or stroke⁴.

These processes can occur in any large artery but most commonly affect the coronary arteries (heart), carotid arteries (neck/brain), and the aorta. Local inflammation and calcification make plaques more vulnerable to rupture.

Treatment and medical management

Den viktigste behandlingen av aterosklerotisk hjerte- og karsykdom (ASCVD, aterosklerotisk karsykdom) er å redusere risikofaktorene som driver sykdomsutviklingen. Det innebærer først og fremst å senke LDL-kolesterolet (det "dårlige" kolesterolet), kontrollere blodtrykket, optimalisere blodsukker ved diabetes, og endre levevaner¹.

Alle pasienter med eller i risiko for aterosklerose bør få grundig veiledning om:

• Fysisk aktivitet: Det anbefales minst 90–150 minutter med moderat til intensiv aktivitet per uke, tilpasset alder og funksjon¹.

• Kosthold: Dietten bør være rik på fiber, enumettede fettsyrer, fet fisk, grønnsaker og frukt. Inntak av mettet fett (særlig rødt og bearbeidet kjøtt, innmat), transfett (industrielt bakverk) og salt bør reduseres mest mulig. Saltinntaket bør være under 5 gram daglig.

• Røyking: Røykere bør tilbys røykeslutt med støtte eller kurs.

• Overvekt: Vektreduksjon anbefales ved overvekt/fedme, i kombinasjon med økt aktivitet og sunt kosthold¹.

• Moderat alkoholinntak og stressmestring inngår også som viktige tiltak.

Blodtrykksbehandling, kolesterolsenkende medisiner (statiner eller andre), og god blodsukkerkontroll er sentrale medikamentelle tiltak. Ved uttalt innsnevring i kransarterier eller store kar kan kirurgisk behandling være aktuelt (for eksempel PCI – utblokking/stenting – eller bypass-operasjon).

Complications

Atherosclerotic disease can lead to a wide range of severe complications, depending on which arteries are affected. The most common include:

• Coronary artery disease (CAD) – causes angina pectoris and myocardial infarction

• Cerebrovascular disease (CVD) – ischemic stroke and transient ischemic attack (TIA)

• Peripheral artery disease (PAD) – causes pain during walking, ulcers, and in severe cases, tissue necrosis

• Abdominal aortic aneurysm – dilation of the main aorta

• Renal artery stenosis – narrowing of the arteries supplying the kidneys

All of these conditions can result in severe disability or death, making early treatment and prevention essential¹.

Physiotherapy

Physiotherapists play a central role in both primary and secondary prevention of atherosclerosis. Their work includes:

• Patient education: Information about heart-healthy nutrition, physical activity, weight management, stress reduction, smoking cessation, and how different factors affect disease progression.

• Individualized exercise guidance: Tailoring physical activity such as aerobic training, strength training, and activity recommendations based on function, risk profile, and complications. Physiotherapists can design specific training programs and monitor progress and safety.

• Motivation and coping: Supporting long-term lifestyle changes and addressing challenges related to pain, anxiety, or loss of function.

• Rehabilitation: Participation in cardiac rehabilitation after myocardial infarction or major interventions, aiming to improve fitness, strength, and quality of life while preventing recurrence².

Lifestyle factors and emerging perspectives

Even with optimal management of traditional risk factors, there remains a residual risk for disease. Newer research highlights the importance of additional lifestyle-related factors in both the development and progression of atherosclerosis:

• Chronic stress, sleep disorders, environmental factors (e.g., air pollution, noise), and gut microbiota composition influence systemic inflammation and can either promote or inhibit disease progression¹.

• Physical fitness – particularly strength and muscle function – has major impact. High physical capacity lowers risk, even in overweight individuals or those with other risk factors.

• Preservation of muscle mass, especially through resistance training, reduces age-related inflammation and creates a more favorable inflammatory environment.

• Diet: Strong evidence supports reducing intake of added sugars, refined grains, and industrial trans fats, while increasing whole plant-based and animal-based foods. Fiber and healthy fats from fish, nuts, and oils are particularly beneficial.

• Gut microbiota and inflammation: Dysbiosis may increase intestinal permeability, leading to low-grade systemic inflammation. This elevates the risk of atherosclerosis and other non-communicable diseases, making it an increasingly important target in prevention and treatment¹.

References

1. Lechner K, von Schacky C, McKenzie AL, Worm N, Nixdorff U, Lechner B, et al. Lifestyle factors and high-risk atherosclerosis: Pathways and mechanisms beyond traditional risk factors. Eur J Prev Cardiol. 2020;27(4):394–406. Available from: https://pubmed.ncbi.nlm.nih.gov/31408370/ [last accessed: 05.07.2025]

2. Pahwa R, Jialal I. Atherosclerosis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020. Available from: https://www.ncbi.nlm.nih.gov/books/NBK507799/ [last accessed: 05.07.2025]

3. Biros E, Karan M, Golledge J. Genetic variation and atherosclerosis. Curr Genomics. 2008;9(1):29–42. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2674308/ [last accessed: 05.07.2025]

4. Dr. Matt and Dr. Mike. Atherosclerosis in 2 minutes. YouTube. Available from: https://www.youtube.com/watch?v=VmWj-Rl4-7w [last accessed: 05.07.2025]

5. Dr. Matt and Dr. Mike. Atherosclerosis – Pathogenesis, risk factors and complications. YouTube. Available from: https://www.youtube.com/watch?v=jwL4lkSlvSA [last accessed: 05.07.2025]

6. Study.com. Atherosclerosis: Stages & Prognosis. Available from: https://study.com/academy/lesson/atherosclerosis-stages-prognosis.html [last accessed: 05.07.2025]