High cholesterol levels are bad, but it is really high oxidized LDL cholesterol in the arterial plaques that matters.
LDL cholesterol, while vital for cell function, is inherently vulnerable. It can be easily oxidized, meaning it reacts with oxygen molecules and changes its structure. If you are older, overweight, smoke cigarettes, or have diabetes, those are all conditions that increase oxidant production and inflammation. Those factors change cholesterol in a way that makes it much more dangerous. That is one of the reasons some people have a high cholesterol, but they don’t have much arterial disease if they don’t have other risks.
Oxidized LDL: The Troublemaker: This oxidized LDL becomes a real problem. It has a completely different shape and chemical makeup than the regular LDL. This oxidation process turns LDL cholesterol into a potent inflammatory agent.
Inflammation and Plaque: When oxidized LDL enters the bloodstream, it triggers the immune system. Oxidized LDL is different. You have all seen iron that is changed by rust. Rust is oxidized iron. It that same way, oxidized LDL is different from the LDL in your cell walls, and the body recognizes it as foreign. Your immune system attacks any foreign material in your body. Usually it is attacking bacteria and viruses, but here it is attacking oxidized LDL cholesterol and that is the root cause of arterial catastrophes.
White blood cells, called macrophages, try to engulf and remove the oxidized LDL. However, they often get overwhelmed and become trapped in the artery wall, forming foam cells. This process is one of the critical steps in the development of plaque, the sticky buildup that narrows arteries.
Vulnerable Plaque: Over time, this plaque can become unstable and vulnerable, prone to rupture. You have all seen a boil in the skin. In that case the white cells are attacking staph bacteria and an abscess or collection of pus forms under the skin. These boils rupture or we open them and that leads to healing. It is not like that in the artery. White cells attack oxidized LDL cholesterol and that forms a tiny boil or abscess in the wall of the artery. When that tiny boil ruptures or erodes, it exposes the blood in the artery to raw tissue which kicks off the clotting process. If the clot completely blocks the flow in the artery, the muscle downstream dies, and that is a heart attack. If it is a brain artery that is involved, that causes a stroke. If it is a leg artery that causes gangrene. It is all the same process.
Key Point: While regular LDL can contribute to plaque formation, it's the oxidation process that makes LDL truly harmful, setting off the inflammatory cascade that contributes to vulnerable plaque and its potentially serious consequences.
So, in short, oxidized LDL is the real culprit, triggering inflammation and promoting the development of the unstable plaque that can lead to cardiovascular events like heart attack and stroke.
SUPERB TEACHING. hrs, md,facc
Thank you again will share