FAT METABOLISM (CHOLESTEROL, TRIGLYCERIDES, LIPOPROTEIN A)
LDL cholesterol | triglycerides | lipoprotein | PDF Fat metabolism (cholesterol)
People in different regions of the world have different concentrations of blood lipids. These differences are partly diet-related. A high-fat diet causes higher average blood cholesterol concentrations. However, a large proportion of the differences in cholesterol concentrations in our population are also genetic. Twin studies have shown that one-third of the cholesterol concentration measurable in the blood is diet-related. Two thirds of the cholesterol is produced by the body itself and cannot be influenced by a change in diet.
Cholesterol is a substance produced naturally in the body, primarily in the liver. We need cholesterol, for example, to produce bile acids, hormones and to build cells. However, there are various diseases that can lead to an increase in cholesterol in the blood. This increases our risk of developing atherosclerosis (deposits in the vessels) at an early stage, which in turn can lead to cardiovascular diseases such as heart attacks and strokes.
If several people in your family have suffered from coronary heart disease at an early age or have even died (heart attack or stroke), all family members, including the children, should be examined to see if you have a lipometabolic disorder.
In the blood, we divide cholesterol into two main components. We then speak of the so-called bad LDL cholesterol (low-density lipoprotein) and the good HDL cholesterol (high-density lipoprotein). LDL brings the cholesterol from the liver to all the cells of the body, but also to the vascular wall of the arteries, where it can be deposited. HDL, on the other hand, brings the cholesterol from the body's cells back to the liver and can also absorb the LDL deposited in the vessel walls. In this respect, it has a protective function.
For this reason, it is not enough to know only the value for total cholesterol, which should not exceed 200 mg/dl (5.6 mmol/l). The target value for LDL cholesterol is determined individually. As a rule of thumb, however, you can remember the following: If you have no risk factor or only one, you should aim for an LDL of less than 150 mg/dl (3.9 mmol/l). If there are two or more risk factors, the LDL should not exceed 135 mg/dl (3.5 mmol/l). If, on the other hand, atherosclerosis or even heart disease has already occurred, then an LDL of less than 100 mg/dl (2.6 mmol/l) should be aimed for. This target value also applies to diabetics.
To lower LDL cholesterol, the diet must first be changed. A consultation with a nutritionist can therefore be very useful in some cases. This alone can reduce LDL cholesterol by ten to 20 percent. In the case of the inherited form, however, this measure is often not sufficient and medication must be administered. To favourably influence the "good" HDL cholesterol, one should exercise a lot and regularly. Endurance sports such as jogging, swimming and cycling are best.
Most of the time, people only talk about cholesterol. However, there are other blood fats that can pose a risk for cardiovascular disease. First and foremost among these are the triglycerides. Triglycerides are the visible white fat we all know and they are needed by muscles for energy. Triglycerides should not be higher than 180 mg/dl when fasting. Since there are a lot of triglycerides in the food, 3-6 hours after eating, this leads to an increase to about double. One can therefore also imagine that triglycerides can fluctuate considerably from day to day. But triglycerides can rise in the blood not only from high-fat foods. All sweet things (sugar, chocolate) and alcoholic drinks that contain a lot of carbohydrates also lead to increased levels. This is because the body can produce triglycerides from carbohydrates.
Since triglycerides are strongly dependent on food, a low-fat and high-fibre mixed diet is the most important way to lower blood lipid levels. Fast metabolising carbohydrates and alcohol should be largely avoided. If this measure is not sufficient, the administration of medication can be useful.
Lipoprotein(a), also known as Lp(a) for short, is a blood fat similar to LDL cholesterol whose physiological role is not known. However, Lp(a) plays a major role in the development of atherosclerosis. We know from research that Lp(a) is a leading risk factor for the development and progression of coronary heart disease. Unlike cholesterol, however, it cannot be influenced by dietary changes or medication. The level of Lp(a) in the blood is innate and remains relatively constant until old age.
Individuals who have coronary artery disease or have relatives who have prematurely developed cardiovascular disease should have lipoprotein(a) determined. Since blood levels vary little, a single laboratory determination is generally sufficient. Repeat measurements are not necessary. Normally, a level below 30 mg/dl is considered normal, but this can vary from laboratory to laboratory.
Since it is not possible to directly influence Lp(a ), all other risk factors should be well treated. The target value for LDL cholesterol should be a maximum level of 115 mg/dl.