Lipoproteins And Stroke: What's The Connection?

Lipoproteins are round particles made of fat and proteins that travel in your bloodstream to cells throughout your body. There are five main types of lipoproteins: high-density lipoprotein (HDL), low-density lipoprotein (LDL), very low-density lipoproteins (VLDL), intermediate-density lipoproteins (IDL) and chylomicrons. While HDL is often referred to as good cholesterol, high levels of LDL and VLDL can be harmful to your heart.

Lipoprotein (a), or LP(a), is a type of LDL that increases your risk of cardiovascular problems. LP(a) is a risk factor for atherosclerosis, heart attacks and strokes. While diet and lifestyle choices can affect HDL and LDL levels, your genes determine your LP(a) levels. Some people inherit a gene that makes them more prone to high LP(a) levels, increasing their risk of heart disease.

Several studies have evaluated the association between LP(a) and ischaemic (thrombotic) stroke. A significant association between increased levels of LP(a) and the risk of ischaemic stroke has been observed. LP(a) levels were also found to be significantly associated with the risk of large artery atherosclerosis (LAA) and intracerebral haemorrhage (ICH).

Lipoprotein(a) is a risk factor for stroke

Lipoprotein(a) [Lp(a)] is a lipoprotein moiety that consists of a core lipoprotein molecule, containing apolipoprotein B (apo-B100), to which a glycoprotein of variable molecular weight, apolipoprotein (a) [apo(a)], is covalently attached via a cysteine-cysteine disulfide bond. Lp(a) is hypothesised to speed up the development of atherosclerosis by binding LDL, calcium, and other components into an atherosclerotic plaque on the walls of blood arteries.

Lp(a) is a risk factor for stroke, with several studies finding a significant association between increased levels of Lp(a) and the risk of ischaemic stroke. However, the evidence is mixed, with some studies finding no link between Lp(a) levels and stroke risk.

Lp(a) is also a risk factor for the large artery atherosclerosis (LAA) and intracerebral haemorrhage (ICH) subtypes of ischaemic stroke.

Lipoprotein(a) is a type of LDL (bad cholesterol)

Lipoprotein(a) or Lp(a) is a type of LDL cholesterol, often referred to as "bad cholesterol". It is composed of a core lipoprotein molecule, which contains apolipoprotein B (apo-B100), and a glycoprotein of variable molecular weight, apolipoprotein (apo(a)), which is attached to the former via a covalent bond.

Lp(a) is hypothesised to speed up the development of atherosclerosis by binding LDL, calcium, and other components into an atherosclerotic plaque on the walls of blood arteries. The LPA gene regulates the variation in Lp(a) plasma concentrations, with larger apo(a) isoforms related to lower values of Lp(a).

Lp(a) levels are greater in the Asian population compared to the Caucasian population, confirming a greater risk of stroke in the former. Increased Lp(a) levels could be considered as a predictive marker for identifying individuals who are at risk of developing strokes, large artery atherosclerosis (LAA), and intracerebral haemorrhage (ICH).

High levels of lipoprotein(a) are a risk factor for atherosclerosis

Lipoprotein(a), or Lp(a), is an independent risk factor for atherosclerosis. While the absolute risk threshold is not yet generally accepted, the European Atherosclerosis Society recognises that an Lp(a) level of 50 mg/dL or more confers a higher risk of cardiovascular disease. This is supported by a study by Mehta et al., which found that an Lp(a) level > 50 mg/dL and CAC score were independently associated with an increased risk of developing atherosclerotic cardiovascular disease (ASCVD).

A larger, more recent analysis has demonstrated that elevated Lp(a) levels are an independent risk factor for coronary heart disease (CHD) in both African Americans and Caucasians. This analysis also found that the risk of CHD is continuously associated with Lp(a) levels, contradicting previous studies that suggested Lp(a) was only a risk factor when levels were extremely high.

Furthermore, a 20-year follow-up study of the Atherosclerosis Risk in Communities (ARIC) cohort found that elevated Lp(a) levels are associated with a similar degree of risk in both African Americans and Caucasians. This suggests that high Lp(a) levels are a long-term risk factor for atherosclerosis, regardless of ethnicity.

The approach to managing patients with elevated Lp(a) levels is still emerging, as they do not respond well to changes in diet or statin therapy. However, the results of the Familial Atherosclerosis Treatment Study (FATS) showed that the risk associated with very high Lp(a) levels could be eliminated by substantially lowering LDL-C levels with lovastatin plus colestipol or niacin plus colestipol.

Atherosclerosis is the build-up of plaque inside blood vessels

Atherosclerosis is the thickening or hardening of the arteries caused by a buildup of plaque in their inner lining. This plaque is made up of deposits of fatty substances, cholesterol, cellular waste products, calcium, and fibrin. As it builds up in the arteries, the artery walls become thickened and stiff, reducing blood flow and oxygen supply to the vital body organs and extremities.

Atherosclerosis is a slow, lifelong progression of changes in the blood vessels that may start as early as childhood. However, it can progress rapidly. The exact cause of atherosclerosis is not clear, but it is believed to be caused by elevated levels of cholesterol and triglycerides in the blood, tobacco smoking, and high blood pressure.

The complications of plaque buildup, including heart attacks and strokes, are the leading cause of death worldwide. Atherosclerosis can cause a heart attack if the blood supply is reduced to the heart, and a stroke if the blood supply is cut off to the brain. Severe pain and tissue death may occur if the blood supply is reduced to the arms and legs.

Atherosclerosis increases the risk of cardiovascular problems

Atherosclerosis is a slow, lifelong process of changes in the blood vessels that may start in childhood and get worse as one ages. It is a hardening of the arteries caused by the gradual buildup of plaque on the walls of the arteries. This plaque consists of fat, cholesterol, cellular waste products, calcium, and fibrin, a clotting material in the blood. As the plaque builds up, the walls of the blood vessels thicken, narrowing the channel within the artery and reducing blood flow. This, in turn, lessens the amount of oxygen and other nutrients reaching the body.

Atherosclerosis can lead to conditions such as coronary heart disease, angina, carotid artery disease, peripheral artery disease, and chronic kidney disease. When the plaque buildup occurs in the heart, brain, or kidneys, it can lead to more serious complications such as heart attacks or strokes.

Lipoproteins, specifically lipoprotein(a) (Lp(a)), have been identified as a risk factor for atherosclerosis and, consequently, for cardiovascular problems such as strokes. Lp(a) is a lipoprotein moiety that consists of a core lipoprotein molecule containing apolipoprotein B (apo-B100) and a glycoprotein called apolipoprotein(a) [apo(a)]. Lp(a) is hypothesised to speed up the development of atherosclerosis by binding LDL, calcium, and other components into an atherosclerotic plaque on the walls of blood arteries.

Several studies have evaluated the association between Lp(a) and ischaemic (thrombotic) stroke, with some studies finding a significant association between increased levels of Lp(a) and the risk of ischaemic stroke. However, there are also contradictory findings, which could be due to factors such as small sample sizes, different ethnic groups, and the influence of oestrogens in women participating in the studies.

Overall, atherosclerosis increases the risk of cardiovascular problems by interfering with the normal functioning of the cardiovascular system. It can limit or block blood flow to various parts of the body, including the heart and brain, leading to serious complications such as heart attacks and strokes.

Frequently asked questions