Diseases and Complications from High Cholesterol
Studies have shown that having high cholesterol can be a leading cause of many diseases, particularly those affecting the vasculature. Since LDL shuttles cholesterol from the liver to the body via the bloodstream, the blood vessels themselves are affected.
Deposition of fats can play a role in the hardening and narrowing of the lumen of a blood vessel. When the blood vessel is sufficiently occluded (or even totally blocked), neighboring organs and regions that rely on a consistent and fresh blood supply are affected.
Diabetes. A dangerous combination of hypertension and diabetes is not uncommon. Diabetics suffer from elevated levels of glucose in their blood. Glucose is a “sticky” sugar that attaches itself to blood and lipoproteins. Studies have shown that HDL levels are slightly depressed, TGs are increased and LDL levels are slightly increased in diabetics. Furthermore, the glucose modification of VLDL and LDL show that these lipoproteins stay longer in the blood, possibly due to a decrease in their excretion. Excess LDL that remains in the blood becomes oxidized over time and can contribute to plaque formation.
Coronary Artery Disease (CAD). Sometimes called coronary heart disease. The heart is a major muscle in the body that needs a constant supply of fresh blood. This fresh blood is supplied by the coronary arteries. The blockage and hardening of these arteries by atheromas is called atherosclerosis. It is thought that atherosclerosis is initiated possibly by damage to the blood vessel wall. Monocytes adhere to these vessel walls and enter the tissue (at which time these monocytes become macrophages). These macrophages proceed to engulf oxidized LDL and are transformed into structures called foam cells. These foam cells accumulate in the blood vessel and release factors causing smooth muscle proliferation, platelet aggregation and the release of fibroblast growth factor. This buildup of factors in the area form a plaque (with a cholesterol core) that contributes to the narrowing of the blood vessel lumen. The plaque also calcifies during the buildup and causes hardening.
All these steps that occur to cut off the fresh blood supply to the heart can cause chest pains (stable angina, vasospastic angina, unstable angina) or even a heart attack (myocardial infarction).
Hypertension. High blood pressure is called hypertension. The process of atherosclerosis described above causes the hardening of the blood vessels. These vessels now have less compliance to them and as a result, the heart must work harder to pump the necessary blood to the body. This causes excessive strain on the cardiovascular system.
Stroke. Just as the blood vessels key to supplying the heart with a fresh supply of blood is essential for the heart, the same is true of all the other blood vessels in the body. Narrowing and hardening of blood vessels that supply the brain can cause strokes. It must be pointed out that complete blockage is not always necessary to cause vascular accidents. For example, a small pocket of air that would normally flow through with ease in a normal blood vessel may become trapped and act as a plug when the blood vessel is sufficiently narrowed.
Peripheral Vascular Disease. Using the same principles as above, the failure of the blood stream outside of the heart and brain to deliver fresh blood to key organs can cause localized infarcts.