Coronary heart disease blood lipid levels

Standard lipid screening to obtain a cholesterol profile for the risk of cardiovascular disease routinely reports total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides. Cholesterol values are reported in milligrams per deciliter of blood (mg/dL). Different organizations have made recommendations for normal cholesterol levels, but these must be interpreted carefully, as they are contingent on other risk conditions. For example, the recommendations for smokers or those with a family history of heart disease will be lower for someone without these conditions. The National Center for Cholesterol Education (NCEP) endorsed by the American Heart Association believes that LDL is the primary cholesterol component to determine therapy. LDL cholesterol accounts for 60—70% of blood serum cholesterol. An LDL less than 160 mg/dL is recommended for individuals with no more than one risk factor and less than 100 mg/dL for individuals with coronary heart disease. NCEP classifies HDL, which comprises between 20% and 30% of blood cholesterol, below 40 mg/dL as low. Triglycerides are an indirect measure of VLDL cholesterol. The NCEP considers a normal triglyceride level as less than 150 mg/dL. 

Cardiovascular diseases are a major cause of death in developed countries, making prevention a priority for public health policy. Research evidence over years has shown that cardiovascular diseases can be managed and even prevented by healthful eating practices involving a resveratrol-enriched diet of whole plant foods such as offered by superfruits. For more than fifty years, research has shown that a healthful, active lifestyle combined with the dietary benefit of high fruit and vegetable intake may lower blood lipid levels, blood pressure, and risk of coronary heart disease and stroke. 

In the 1950s, Keys and co-workers pioneered work indicating the very different effects of saturated and unsaturated dietary fats on blood cholesterol levels and, in turn, on coronary heart disease. Based on this work, the lipid hypothesis states that there is a connection between the FA composition of the diet and the cholesterol content of the blood serum, in that saturated FA increase cholesterol, while PUFA decrease it. Later, it was established that the type of fat affected the lipid level more than cholesterol in blood. Keys research has provided the basis for the recommendation that fats with a relatively low proportion of PUFA be replaced by fats and oils that are rich in PUFA. 

Clinical coronary heart disease usually appears at least two or three decades after the onset of pathological lesions of coronary atherosclerosis. Epidemiological studies emphasize that hyperlipidemia, especially hypercholesterolemia, is a primary risk factor which should be construed as a warning sign. Normalization of high blood-lipid levels could start, therefore, long before the acute phases of coronary heart disease are manifest. 

FAT AND HEALTH PROBLEMS. Fats either cause heart disease or cancer—or so it seems. As for coronary heart disease, the blame on fats arises primarily from two factors (1) atherosclerotic deposits in blood vessels are composed of cholesterol and other fatty substances and (2) increases in certain fat components of the blood contribute to atherosclerosis. Fats are transported in the blood in the form of lipid-protein complexes—lipoproteins. It is the blood levels of cholesterol, triglycerides, and certain lipoproteins which are considered risk factors in the development of heart disease. 

Etiology - In the study of the causes of atherosclerosis. the factors found most likely to be present in the living system prior to death, in relation to the proven presence of coronary atherosclerosis at autopsy, are advanced age, elevated serum cholesterol, and elevated blood pressure, with elevated blood lipids and the presence of diabetes appearing influential. Other measurable metabolic parameters found to correlate as coronary heart disease risk factors are elevated serum uric acid, , lowered serum albumin levels, lowered lipoprotein lipase and lowered endogenous heparin. Of these factors, "cholesterol" continues as a favorite research topic. 

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. 

Alpha-tocopherol acetate (vitamin E) has no effect on lipid levels but is a powerful antioxidant. Considerable evidence points to oxidation of LDL as an essential step in the development of atheroma, and therefore interest has centred on the role of either endogenous or therapeutic vitamin E in prevention of atheroma. Reduced concentrations of vitamin E in both blood and fat (vitamin E is a fat soluble vitamin) are found in inhabitants of countries with a high prevalence of ischaemic heart disease, and (within these countries) in patients who develop ischaemic heart disease. A high dose reduced by half the risk of myocardial infarction in 2000 patients with angina and positive coronary angiogram. However most other studies have failed to confirm this finding and there is no indication at present for routine prescribing of a-tocopherol in the treatment or prevention of atherosclerosis. 

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