Theme 3: Lecture 17 - Primary and secondary dyslipidaemias Flashcards
According to the Framingham heart study, what are the major CVD risk factors
- High blood pressure
- High blood cholesterol
- Smoking
- Obesity
- Diabetes
- Physical inactivity
Name 3 studies that investigate the risk factors for CVD
- Framingham heart study
- Cholesterol treatment trialists
- Copenhagen city heart study
What was the aim of the cholesterol treatment trialists study
conducting periodic meta-analyses of large-scale (≥1000 participants), long-term (≥2 years treatment duaration) unconfounded, randomized controlled trials of lipid intervention therapies
What were the findings of the cholesterol treatment trialists
- Reduction of LDL cholesterol using statin therapy substantially reduces the risk of major vascular events (major coronary events, strokes or the need for coronary revascularization) and vascular mortality
- Further reductions in LDL cholesterol with more intensive statin therapy produce further reductions in the incidence of major vascular events
Modifiable risk factors for CVD
- Smoking
- Obesity
- Sedimentary lifestyle
- Diabetes
- High cholesterol
- Hypertension
- Excess alcohol intake
Un-modifiable risk factors for CVD
- Age > 50
- Gender
- Genetic factors
- Pre-existing CVD
Name 2 risk calculator tools
- QRISK3
- NICE guidelines
What does a QRISK3 over 10 mean
- 10% risk of CVD event over the next ten years
- Primary prevention with lipid lowering therapy (such as statins) should be considered
Why treat lipid disorders which are often asymptomatic
- To reduce the atherosclerotic process and the incidence of clinical vascular disease.
- To prevent pancreatitis which is associated with grossly increased serum triglyceride (>10mmol/L, usually >20mmol/L).
Describe LDLRs
- LDLR is a cell-surface receptor (encoded by LDLR gene) that recognizes ApoB-100 (apolipoproteinB-100) which is embedded in the phospholipid outer layer of LDL particles.
- Present on most cells but the majority on the liver.
- LDLR on hepatocytes binds to LDL particles and remove them from the circulation. The LDLR then return to the cell surface to repeat this process.
What is the first line treatment for hypercholesterolaemia
Statins
Describe Ezetimibe
- Is a potent and selective inhibitor of absorption of cholesterol in the small bowel.
- The drug and its active glucuronide metabolite impair the intestinal reabsorption of both dietary and hepatically excreted biliary cholesterol through inhibition of a membrane transporter
What is the membrane transporter that Ezetimibe inhibits
Niemann-Pick C1-Like 1 (NPC1L1)
Describe PCSK9 inhibitors
PCSK9 functions as a binding protein; it is expressed primarily in hepatocytes and after secretion binds to the LDLR and promotes their degradation. By blocking PCSK9, these drugs result in increased availability of LDLR to remove LDLC from the circulation.
What are the 3 main patterns of lipid profiles in lipoprotein abnormality
- Hypercholesterolaemia
- Mixed hyperlipidaemia
- Hypertriglyceridaemia