Cholesterol/heart disease

Cholesterol Heart disease is linked to high blood cholesterol levels. What is the percent composition of the elements in a molecule of cholesterol (C27H45OH) ... 

HISTORY. The cholesterol-heart disease debate was officially opened when, in 1953, Dr. Ancel Keys at the University of Minnesota reported a positive correlation between the consumption of animal fat and the occurrence of atherosclerosis in humans Subsequently, other studies correlated high blood levels of cholesterol with increeised incidence of atherosclerosis in humans. In 1964, the American Heart Association recommended that the general public reduce cholesterol intake to 300 mg/day. Subsequently, various government and health agencies around the world have followed suit. Thus, attention was, and still is, centered on cholesterol. 

Also see CHOLESTEROL HEART DISEASE and HYPERLIPOPROTEINEMIAS [Hyperlipidemias].)... 

Cholesterol is biosynthesized in the liver trans ported throughout the body to be used in a va riety of ways and returned to the liver where it serves as the biosynthetic precursor to other steroids But cholesterol is a lipid and isn t soluble in water How can it move through the blood if it doesn t dis solve in if The answer is that it doesn t dissolve but IS instead carried through the blood and tissues as part of a lipoprotein (lipid + protein = lipoprotein) The proteins that carry cholesterol from the liver are called low density lipoproteins or LDLs those that return it to the liver are the high-density lipoproteins or HDLs If too much cholesterol is being transported by LDL or too little by HDL the extra cholesterol builds up on the walls of the arteries caus mg atherosclerosis A thorough physical examination nowadays measures not only total cholesterol con centration but also the distribution between LDL and HDL cholesterol An elevated level of LDL cholesterol IS a risk factor for heart disease LDL cholesterol is bad cholesterol HDLs on the other hand remove excess cholesterol and are protective HDL cholesterol IS good cholesterol... 

Low density lipoprotein (LDL) (Section 26 11) A protein which cames cholesterol from the liver through the blood to the tissues Elevated LDL levels are a nsk factor for heart disease LDL is often called bad cholesterol... 

Reduction in semm Hpids can contribute significantly to prevention of atherosclerosis. In 1985 a consensus report indicating that for every 1% reduction in semm cholesterol there is a 2% reduction in adverse effects of coronary heart disease was issued (145). Recommended semm cholesterol concentration was 200 mg/dL for individuals under 30 years of age, and individuals having concentration 240 mg/dL and LDL-cholesterol over 160 mg/dL should undertake dietary modification and possibly pharmacotherapy (146). Whereas the initial step in reducing semm cholesterol is through reduction of dietary cholesterol intake, a number of dmgs are available that can affect semm Hpid profile (see Fat substitutes). The pathway to cholesterol synthesis is shown in Figure 2. 

We hear a lot these days about the relationships between saturated fats, cholesterol, and heart disease. What are the facts It s well established that a diet rich in saturated animal fats often leads to an increase in blood serum cholesterol, particularly in sedentary, overweight people. Conversely, a diet-lower in saturated fats and higher in polyunsaturated fats leads to a lower serum cholesterol level. Studies have shown that a serum cholesterol level greater than 240 mg/dL (a desirable value is <200 mg/dL) is correlated with an increased incidence of coronary artery disease, in which cholesterol deposits build up on the inner walls of coronary arteries, blocking the flow of blood to the heart muscles. 

Focus On... Saturated Fats, Cholesterol, and Heart Disease 1090... 

LDL is the major carrier of cholesterol to the periphery and supplies the cholesterol essential for the integrity of nerve tissue, steroid hormone synthesis, and cell membranes. The association between elevated plasma cholesterol carried in LDL and the risk of coronary heart disease has been well established. LDL is also sometimes called the bad cholesterol. 

Discuss cholesterol, HDL, LDL, and triglyceride levels and how they contribute to the development of heart disease. 

HDL cholesterol protects against heart disease so the higher the numbers the better. An HDL level less than 40 mg dL is low and considered a major risk factor for heart disease Triglyceride levels Hiat are borderline (150-190 mg dL) or high (above 190 mg dL) may need treatment in some individuals. 

An increase in serum lipids is believed to contribute to or cause atherosclerosis, a disease characterized by deposits of fatty plaques on the inner walls of arteries. These deposits result in a narrowing of the lumen (inside diameter) of the artery and a decrease in blood supply to the area served by the artery. When these fatty deposits occur in the coronary arteries, the patient experiences coronary artery disease. Lowering blood cholesterol levels can arrest or reverse atherosclerosis in the vessels and can significantly decrease the incidence of heart disease. 

Hyperlipidemia, particularly elevated serum cholesterol and LDL levels, is a risk factor in the development of atlierosclerotic heart disease. Other risk factors, besides cholesterol levels, play a role in the development of hyperlipidemia. Additional risk factors include ... 

While the fibric acid derivatives have antihyperlipidemic effects, their use varies depending on the drug. For example, Clofibrate (Atromid-S) and gemfibrozil (Lopid) are used to treat individuals with very high serum triglyceride levels who present a risk of abdominal pain and pancreatitis and who do not experience a response to diet modifications. Clofibrate is not used for the treatment of other types of hyperlipidemia and is not thought to be effective for prevention of coronary heart disease. Fenofibrate (Tricor) is used as adjunctive treatment for the reduction of LDL, total cholesterol, and triglycerides in patients with hyperlipidemia. 

Goldberg Arnold R, Kaniecki D, Tak Piech C, et al. An economic evaluation of HMG-CoA reductase inhibitors for cholesterol reduction in the primary prevention of coronary heart disease. 11th International Conference on Pharmacoepidemiology. Montreal, Quebec, Canada, 1995. 

The Serum Cholesterol Is Correlated With the Incidence of Atherosclerosis Coronary Heart Disease... 

Familial hypertriacylglycerolemia (type IV) Overproduction of VLDL often associated with glucose intolerance and hyperinsulinemia. Cholesterol levels rise with the VLDL concentration. LDL and HDL tend to be subnormal. This type of pattern is commonly associated with coronary heart disease, type II diabetes mellitus, obesity, alcoholism, and administration of progestational hormones. 

Various authors The cholesterol facts. A summary of the evidence relating dietary fats, serum cholesterol, and coronary heart disease. Circulation 1990 81 1721. 

Useful information on nutrition, on the role of various biomolecules—eg, cholesterol, lipoproteins—in heart disease, and on the major cardiovascular diseases.)... 

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