Cholesterol / lipid metabolism

The lipid profile (total cholesterol, LDL, HDL, triglycerides) is the standard group in cardiovascular diagnostics, complemented by lipoprotein(a) as a genetically determined value and oxidised LDL. Among the LDL subclasses a distinction is made between large and small, dense particles (type B). Fully included in Prevent 360.

What the lipid profile shows

Fats and cholesterol do not dissolve in blood; they are transported in lipoproteins – particles with a core of triglycerides and cholesterol esters and a shell of phospholipids and apolipoproteins. After a meal, the gut packs dietary fat into chylomicrons, whose triglycerides are split off by lipoprotein lipase on the vessel walls of muscle and fat tissue. The liver releases VLDL, which loses triglycerides in the same way and becomes cholesterol-rich LDL via IDL; LDL supplies the cells and largely returns to the liver via the LDL receptor. HDL takes up excess cholesterol from the tissues and brings it to the liver. The lipid profile shows how this cycle is currently balanced.

Low lipid values – what happens in the body?

When lipid values are low overall, the liver is producing few lipoproteins, taking them back up particularly quickly, or little fat is reaching the blood from the gut. This occurs with malnutrition, an overactive thyroid, severe liver disease, disorders of fat absorption and during acute inflammation. Most cells can make cholesterol themselves and therefore do not depend on LDL. In rare inherited disorders in which hardly any apoB-containing lipoproteins are formed, however, the fat-soluble vitamins E, A and K are also transported less well – with consequences for nerves, eyes and blood clotting.

High lipid values – what happens in the body?

Raised lipid values arise in different patterns. When mainly LDL rises, the particles are being removed from the blood more slowly via the LDL receptor – for example with inherited variants, an underactive thyroid or after the menopause. When mainly triglycerides rise, the liver is producing more VLDL, often in the context of insulin resistance; HDL then falls, and small, dense LDL particles are formed. All apoB-containing particles can penetrate the inner vessel wall, be retained there and become oxidised; scavenger cells take them up and turn into foam cells, from which arteriosclerotic plaques develop. Raised values also occur with kidney disease, bile congestion and with certain medications.

The interpretation is given in your report.