B.1 Dyslipidaemia Flashcards
What is hypercholesterolaemia and what does it lead to?
Elevated plasma cholesterol
Leads to atherosclerosis
What is atherosclerosis and what does it lead to?
Focal lessons (plaques) on the inner surface of an artery
Leads to ischaemic heart disease (IHD)
Peripheral vascular disease (PVD)
Cerebrovascular Disease
What is IHD?
Ischaemic heart disease :Inadequate blood flow to the heart
What is peripheral vascular disease ?
Leg arteries become narrow which causes pain when excising
What is cerebrovascular disease ?
Refers to a group of conditions the affect the blood vessels and the supply to the brain.
Pre-dispose towards a stroke
What are the risk factors associated with atherosclerosis?
Genetic Hypercholestrolaemia (raised LDL or lowered HDL) Hypertension Smoking Obesity Hyperglycemia (poor control of glucose) Reduced physical activity Infection?
Name a few drugs that can induce dyslipidaemia (elevation of plasma cholesterol, triglycerides or both, or a low HDL cholesterol level)
Beta-blockers Thiazides Corticosteroids Retinoids (require monitoring) Oral contraception Anti HIV drugs
What is a lipoprotein and name the lipoprotiens?
A biochemical assembly whose primary function is to transport hydrophobic lipid molecules. Central core contains cholesterol ester and triglycerides surrounded by phospholipids , cholesterol and apolipoproteins.
HDL
LDL
VLDL
What is the pathway of delivery of HDL?
Absorbs cholesterol from cell breakdown and transfers it to VLDL and LDL.
Transports cholesterol to the liver where it can be removed form the blood stream before it builds up in the arteries.
What is the pathway of LDL?
Large component of cholesterol, taken up by the liver and tissues, via endocytosis via LDL receptor
(transported to the arteries)
What is the pathway of VLDL?
Transports cholesterol and TGs to the tissues, where the TGs are removed leaving:
What are Chylomicrons?
Transports triglycerides and cholesterol from GI tract to the liver. Free FA released and cholesterol is stored, oxidised to bile salts or released to:
What is Xanthomata?
Sign of hypercholestrolaemia (dyslipidaemia)
- yellow streaks
yellow plaques on eyes or wrists (should examine cholesterol levels)
What is Athrogenesis and describe the pathway
Athrogenesis: Inflammatory response to injury
Smoking, hypertension, turbulent flow damage the epithelium of the blood vessel (vascular endothelial)
Injury causes monocytes/macrophages to migrate to the site of damage.
This releases ROS (reactive oxygen species) which causes oxidative damage.
ROS: superoxide and hydrogen peroxide
LDL near the area become oxidised, which can damage the receptor on the vascular epithelium, preventing the correct uptake of LDL
As a result foam cells (cholesterol rich) diposit on top of the arterial wall (fatty streak)
What type of inhibitors are statins?
HMG-CoA Reductase Inhibitor (enzyme inhibitor)
What is the brief pathway of the formation of cholesterol?
Hydroxymethyglutaryl is metabolised into Mevalonate then mevalonate is metabolised into cholesterol
What do statins do?
Inhibits the first step synthesis of cholesterol in the body
Out of simvastatin, pravastation, atrovastatin, fluvastation which is the most safe and effective?
Atrovastatin
What is alirocumab and how does it work?
MAB
a PCSK9 inhibitor (natural protein in the body)
PCSK9 binds to LDL receptor and leads to its degredation
Alirocumab increases the number of hepatic LDL receptors and lowers LDL
what is fibrates and how does it work?
Activates PPAR-a, alters lipoprotein metabolism
Also reduces triglycerides
ReducesIHD but not mortality
Adverse effect rhabdomyoysis
what is fibrates and how does it work?
Activates PPAR-a, alters lipoprotein metabolism
Also reduces triglycerides
Reduces IHD but not mortality
Adverse effect rhabdomyoysis
