Coronary Artery Disease

Coronary artery disease is one of the deadly diseases which are responsible for nearly three-quarters of a million deaths in the United States each year. It is a serious medical problem that affects about 7 million people annually. This disease is described as a condition where the coronary arteries, the nutrient supplier blood vessel of the heart, are clogged by the fatty plaque called atherosclerotic plaque. It causes lack blood supply flows to the heart. Insufficient blood flow to the heart muscle from the narrowing of coronary artery may result in angina pectoris or chest pain and heart attacks. However, some individuals have no symptoms or signs; others go through angina pectoris and still others suffer from heart attack. This disease is actually caused by many factors. However, there are two major causes of this disease which include high level of cholesterol and smoking habit.

People with high level of cholesterol in their body are more prone to coronary artery disease. We know that the coronary arteries of the sufferers are clogged by fatty plaque. This is actually because of the presence of cholesterol, one kind of fatty molecule, in their blood stream. It accumulates in the inner wall of coronary arteries by the presence of specific receptors in the vessel. It undergoes oxidation process together with the carrier-protein called lipoprotein. The protein also binds to sugar, and this process stimulates the vessel wall to secrete substance attracting monocytes. Monocyte is one kind of white blood cell which will change into macrophage, and ingest the oxidizing cholesterol-protein-sugar complex, in order to form the foam cells. Foam cells are actually the macrophages that become so filled with oxidized cholesterol-protein-sugar complex, and it has foamy appearance when it is viewed microscopically. Then, it is followed by the presence of T cells, another kind of white blood cell which release chemical substances as the immunity response of this vessel inflammatory. Together with the T cells and the other macrophage, the foam cells form a fatty streak, the promoter of plaque which can grow thicker until it becomes an atherosclerosis.

Like most lipids, cholesterol does not dissolve in water so it must be combined with lipoprotein in order to be water-soluble in the blood stream. There are two kinds of lipoprotein which help the transportation of cholesterol in the body. They are low-density lipoproteins and high-density lipoprotein which has antagonist works. Low-density lipoprotein which is well known as LDLs, transports cholesterol from the liver to body cells for repairing the cell membrane and the production of steroid hormones and bile salts. However, the high-density lipoproteins or HDLs remove excess cholesterol from body cells and bring it to the liver for elimination.  HDLs decrease the cholesterol level in the blood, so that it is commonly referred to as “good cholesterol”, on the contrary, LDLs is called “bad cholesterol” because it can increase the coronary artery disease risks by transferring fat into the cell. The excessive amount of LDLs promotes the formation of the fatty plaque which leads to the atherosclerosis.

Then, what is the contribution of smoking or cigarettes in the coronary artery disease? As many research said, chemical substances in the cigarettes can increase the LDLs level in our body and decrease the HDLs level. But, the mechanism of this process is still being studied now. At least but not last, we know that smoking can lead us to the coronary artery disease.

It is clear that coronary artery disease is caused by the presence of cholesterol in our body and it is compounded by smoking habit. We can do preventive action by maintaining healthy lifestyle in the way of keeping our diet from food containing cholesterol, having exercise regularly, and take a rest enough.

References :

1.       Tortora, Gerard J., Derrickson, Bryan. Principles of Anatomy and Physiology. 13th ed. Wiley. 2011.