Cholesterol – always too high, never too low PART 1
Coronary artery disease with its consequences – heart attacks, cardiac arrhythmias and myocardial functional reduction – is the leading cause of death in most industrial countries, and, very soon it will become the main causes of death in all developing countries. In 2020, the coronary heart disease will occupy the first place in causes of death across the globe. And the the most important highest risk factor for coronary heart disease is cholesterol concentration in blood. There is a linear correlation between cholesterol and the risk of coronary heart disease deaths. The cholesterol lowering by 0.6 mmol / l, ie 23 mg / dL, decreases the mortality in middle age men by 24%.
The result of cholesterol lowering is higher in younger ages. Thus, the cholesterol decrease from 205 to 182 mg / dl, decreases the mortality from coronary heart disease by 54% on 40 years, 39% on 50 years, 27% on 70 years and 19% on 80 years.
The relationship between total cholesterol and mortality from coronary disease is due, in most part, low density lipoprotein (LDL) or the faction known as ‘’bad’’ cholesterol, which in industrialized countries represents 4/5 of the total blood cholesterol.
The relationship between LDL and coronary heart disease mortality is tighter than for total cholesterol. Lowering of the LDL by 0.6 mmol / l, ie 23 mg / dl, produces a mortality decrease by 27%.
You may prefer a much simpler calculation: Decrease of cholesterol by 10% reduces the risk of death by heart attack with 20%. Some preliminary observations for understanding the texts about cholesterol and the acronyms used.
Not being soluble in the aqueous medium, fats circulate in the blood as form of molecular associations with proteins, which provide their solubility and transport. These carrier particles called lipoproteins contain, in addition to cholesterol, apolipoproteins, different amounts of other fats, triglycerides (or triacylglycerols) and phospholipids.
By their density, they differ:
- hylomicrons, particles synthesized in the intestinal wall after the absorption of fat, containing 98-99.5% lipids, which are covered by a layer of protein, representing 0.5-2%;
- very low density lipoprotein (VLDL);
- intermediate density lipoprotein (IDL);
- low-density lipoprotein (LDL);
- high-density lipoprotein (HDL).
The density is determined by the different protein contents and fats. Starting from the bulky molecules, chylomicrons, to the smallest, heavy lipoproteins, the triglycerides (triacylglycerols) progressive decrease is noticed, and the protein percentage increase.