Hardening of the arteries, or arteriosclerosis, appears in large or medium arteries. Accumulation of cholesterol-carrying low-density lipoproteins, or LDLs, on the inner walls of the arteries forms plaques. The plaques cause artery tissues to thicken, thus reducing the inner diameter of the vessels and forming blockages. Excess blood cholesterol remains in circulation and is available as a contributor to such arterial plaques.
Cholesterol
Two types of cholesterol-carrying proteins, LDL and HDL, exist in your blood. LDL carries cholesterol from the liver to other parts of your body and high-density lipoproteins carry leftover cholesterol to your liver for disposal. If your total blood cholesterol is high, over 240mg/dL, the cholesterol has the ability to overwhelm your HDL disposal system and become available for plaque formation. A desirable total cholesterol level is below 200mg/dL.
Arteriosclerosis
A normal artery has three layers: intima, media and adventitia. The intima, or internal layer, is where cholesterol plaque formation begins. The trigger for plaque formation is unknown, but it is thought to occur at damaged areas within the artery. Damage may be caused by smoking, viruses, chemicals or drugs. Excess cholesterol deposits on the damaged area and then inflammatory cells invade the plaque. As the plaque thickens it becomes a hard, fibrous blockage. Sometimes, calcium deposits occur within the plaques. Such thickened areas lose their elasticity, thus becoming hardened arteries, unable to supply proper amounts of blood to your body tissues or organs.
Correlation
Since high cholesterol has been consistently correlated with coronary heart disease death, it is prudent to assume it may be associated with artery hardening. It has been difficult to prove such a correlation, even though cholesterol is a major precursor in the formation of artery-blocking plaques. Many studies have proven that lowering LDL cholesterol reduces coronary events, but few measure artery hardening. In a study by Giacomo Ruotolo and colleagues in the 1998 "Journal of the American College of Cardiology," the authors prove a statistical correlation between lowering LDL cholesterol and lowering the percentage of artery hardening, or stenosis.
Reducing Correlation Risk
Decreasing the correlation between your high cholesterol and artery hardening can be accomplished by several risk-reducing methods. Cholesterol can be lowered with dietary changes, cholesterol-lowering medications and lifestyle changes. Since smoking damages arteries, smoking cessation reduces risk. Exercising at least five days per week improves circulation and causes weight loss, both risk factors to artery hardening plaques. Also, reducing your stress-induced high blood pressure with stress management techniques is beneficial.
Symptoms and Treatment
High cholesterol-correlated hardening of the arteries presents with variable symptoms, depending on the arteries affected. The hardening is a slow process and symptoms don't usually present themselves until the blood supply becomes severely compromised. Heart artery blockage can cause chest pain and brain artery blockages exhibit stroke-like symptoms, while extremity arterial blockages can result in leg or arm pain. Once the arterial blockages form, the only treatment is surgical intervention.
References
- Vascular.co.nz; Hardening fo the Arteries; Damien Mosquera; 2002
- MayoClinic.com; High cholesterol; June 2010
- University of Maryland Medical Center; Artherosclerosis - Overview; David C. Dugdale; May 2009
- "Biochimica et Biophysica Acta"; Cholesterol and Atherosclerosis; P.Libby, M.Aikawa, U.Schonbeck; 2000
- "The Journal of the American College of Cardiology;" Treatment Effects on Serum Lipoprotein Lipids, Apolipoprotiens and Low Density Lipoprotein Particle Size and Relationship...;Giacomo Ruotolo, et al.; November 1998
- MayoClinic.com; Ateriosclerosis/athersclerosis; June 2010
