Cholesterol is found in many parts of animal and human organism, including in most of the body cell membranes (membranes), both those that surround the cells and those found in these. Some places are cholesterol as such, but it is stored and transported predominantly in esterified form, which cholesteryl.
Formation and function
Most of the organism's cells produce cholesterol, so we do not rely on to get the drug supply. In cells synthesized cholesterol from acetyl coenzyme A in a process that has 20-30 enzymatic steps. Cholesterol is also supplied through food, in amounts that depend on diet composition.
Cholesterol has several functions in the organism, including important component of cell membranes. It further involved in the transport of blood fats, and it is a precursor in the formation of both steroid hormones (sex hormones and adrenal corticosteroids) that of bile acids and vitamin, D.
Cholesterol in the blood
Admissions, transport and storage of fats (lipids) takes place through a series of complicated processes, in which cholesterol in several places played an important role. Lipids, which are insoluble in aqueous solutions, such as blood plasma, blood must be transported together with other materials. This happens in so-called lipoproteins, which is a kind of small "package" with an inner portion, including contains cholesteryl and an outer sheath with both cholesterol and protein. It is in these lipoproteins, of which there are several types, most of the blood cholesterol present and measured.
Two of the most important blood-transporting lipoproteins is LDL (LowDensity Lipoprotein, the "bad" cholesterol) and HDL (HighDensity Lipoprotein, the "good" cholesterol). LDL and HDL together constitute the bulk of cholesterol in the blood. Cholesterol in the blood given as mmol / l, and normal values in adults can be 4-6. Previously, cholesterol in the blood indicated as mg / dl and corresponding normal asset value was 150-250.
Cholesterol, health and disease
Cholesterol turnover plays a role in several disease states. Much cholesterol excreted in bile and gall stones consist largely of cholesterol. In certain diseases, eg. diabetes and hypothyroidism , the amount of cholesterol in the blood may be increased as a result of the disease. There are also conditions of inherited, significantly elevated cholesterol levels in the blood.
Much attention is focused on the role cholesterol plays in the development of arteriosclerosis (hardening of the arteries), the compound found in the deposits that form in blood vessel's walls. Empirically, there is a correlation between cholesterol in the blood and the likelihood that it will develop symptomatic atherosclerosis, with eg. angina pectoris or myocardial infarction . The likelihood of such a disease is greater the higher the cholesterol level is, even though at high levels only is someone who develops the disease. Many factors other than cholesterol (eg. Smoking, high blood pressure) seems to be in when it comes to diseaseing risk.
Cholesterol levels in the blood is again from experience, depending on the diet containing cholesterol and fat in general, especially when saturated fat. A sustained high intake of saturated fat leads to increased cholesterol in the blood. Unsaturated fats do not have the same effect, and is therefore, beneficial in food. Saturated fats are found mostly in milk and milk products, margarine and hard in animal meat, while unsaturated fats found in vegetable oils and in fish and sea creatures. In particular, cholesterol-rich food sources are milk fat, egg yolks and offal.
With our Western dietary habits to cholesterol in the blood, which is low in infants, increasing to adulthood and be relatively high compared with that in populations with other dietetic habits. In southern Japan, where the diet contains little fat, so middle-aged men's average cholesterol levels 40% lower than in men of similar age in Oslo.
Measurement of cholesterol
The relationship between cholesterol levels and the likelihood of developing cardiovascular disease has made it plain with measure cholesterol in the blood of many adults. Assessments of the level and by what measures, if any, recommended is dependent on the person's age, as young people often are somewhat lower in level than the older. A common view is that it is good for total cholesterol in the blood of adults is less than five mmol / l located above this level, given often dietary advice, including in less intake of cholesterol-rich food sources of fat and in general, especially saturated fat. The higher your cholesterol level is, the more important it is to bet on the expensive side. At high values (6-7 mmol / l), and especially at very towering (above eight mmol / l), is often recommended as well as use of cholesterol-lowering drugs, as there are several. In assessing the level of cholesterol in blood is not only the total amount of important, but also the relationship between HDL and LDL. The larger share of total cholesterol posed by HDL, the better it is estimated that person's situation to be.