16: Atherosclerosis+ Lipid lowering drugs Flashcards
Explain the role of endothelial dysfunction in the formation of atherosclerotic plaques
- Increased endothelial permeability
- Upregulation of endothelial adhesion molecules
- Leukocyte adhesion
- Migration of leukocytes into the artery wall
Initiation of Fatty Streak formation
Explain the formation of fatty streaks in Atherosclerosis
- Foam cells formation and accumulation in the intima
- Causing drivin of inflammation and triggers the initiation of other effects
- Adherence and entry of leukocytes
- migration of SM cells
- Platelet aggregation
- T-cell activation
Explain the development from a fatty streak to an atherosclerotic plaque
- Foam cells die and dissolve –> bulit up of necrotic core
- Causes an macrophage accumulation
- Formation of a protective fibrous cap by Vascular smooth muscles cell
What is the role of Remnant lipids and Atherosclerosis
Remnant lipids are associated with the inflammatory compound of Atherosclerosis
What are remnant lipids?
Remanants are break down products of cyclomicrons , composed of VLDL and IDL (very high in cholesterole)
Explain the role of LDL in the formation of Atherosclerosis
Formation of Atherosclerosis is highly associated with LDL levels but LDL levels do not cause the inflammatory component of Atherogenesis
What are the diffferences between a stable and an unstable atherosclerotic plaque?
- Unstable plaque have a thin fibrous cap and can easily rupture –>
- Rupture can be triggured by increased BP or inflammation
What does a 10% increase in LDL levels mean in regards to the risk of developing CHD?
•10% increase results in a 20% increase
in CHD risk
Which factors can influence the negative effects of LDL on CHD and atherosclerosis?
Risk factors like:
- low HDL cholesterol
- smoking
- hypertension
- diabetes
Can make the risk for CHD (with high LDL) a lot worse
Explain the role of HDL in CHD and atherosclerosis
- HDL cholesterol has a protective effect for risk of atherosclerosis and CHD
- The lower the HDL cholesterol level, the higher the risk for atherosclerosis and CHD
- HDL cholesterol tends to be low when triglycerides are high
- HDL cholesterol is lowered by smoking, obesity and physical inactivity
What are statins?
What is their drug target?
inhibitors of HMG CoA reductase (enzyme involved in the rate-limiting step of cholesterole synthesis)
Explain the MOA of statins
Statins competitevely inhibit the HMG-CoA reductase (enzyme in the rate limiting step of cholesterole synthesis)
–> reduce cholesterole synthesis in the liver leading to
- Hepatic upregulation of LDL receptors
- increasing binding and removal of LDL cholesterol and LDL precursors from the plasma
Resulting in:
- Decreased LDL
- Increased HDL
What are the main side effect in the use of statins?
General (common): headache and gastrointestinal symptoms (e.g., constipation, diarrhea, flatulence)
Rarer:
- increase in Liver-function test
- myopathy
Explain the effects of the use of Statins on the lipid profile
Generally: Statins lower LDL and triglycerides, increase HDL
- different statins are differently effective
- But in all statins : Rule of 6: double the dose but only 6% reduction in LDL
Explain the effects of statins on CHD and aterostclerosis
They overall: decrease the risks of CHD and atherosclerosis via
- lipid-lowering effects
- Plyothropic effects (not related to lipid profile)