Dyslipidaemia Flashcards
What is a lipoprotein?
1 - molecule composed of lipids
2 - molecule composed of proteins
3 - molecule containing lipids and proteins
3 - molecule containing lipids and protein
- proteins allows lipids to be transported in blood
Which of the following are the main components of lipoproteins?
1 - cholesterol esters
2 - triglycerides
3 - apoproteins
4 - phospholipids
5 - all of the above
5 - all of the above
Where is the majority of the cholesterol in the body produced, the liver or adipose cells?
- liver
What is 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA)?
- intermediate precursor of cholesterol
What is the rate limiting step and the target of statins in an attempt to reduce cholesterol synthesis?
1 - fatty acid synthase
2 - 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase
3 - HMG-CoA synthase
4 - acetyl-coA carboxylase
2 - 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase
- HMG-CoA converted to Mevalonate which can then enter the melanovate cycle to make cholesterol
What is the basic principle of exogenous lipid transport?
1 - transport TAGs throughout the body
2 - transport cholesterol to the body
3 - transport cholesterol from body to liver
4 - transport TAGs and cholesterol from the GIT to the liver
4 - transport TAGs and cholesterol from the GIT to the liver
- processed into chylomicrons
- GIT to lymphatics to liver
Once cholesterol has been synthesised in the liver, it is once again packed up into lipoproteins and sent off into the circulation to carry TAGs to the rest of the body as part of the endogenous. Which type of lipoprotein is used 1st?
1 - chylomicrons
2 - LDL
3 - HDL
4 - VLDL
4 - VLDL
- low density refers to the concentration of cholesterol
- VLDL = high TAGs and low cholesterol
- LDL = low TAGs and high cholesterol
- lipoprotein lipase released from capillaries - triglycerides released from chylomicrons
Once VLDL have been distributed around the body and distributed TAGs they become LDLs (distribute cholesterol around the body as part of the endogenous), and ultimately HDLs. What is the benefit of HDLs?
1 - remove excess TAGs from blood
2 - collect excess cholesterol and return it to the liver
3 - remove cholesterol from plaques
4 - distribute cholesterol around the body
2 - collect excess cholesterol and return it to the liver
- part of the reverse pathway
In endogenous lipid transport very low density lipoproteins (VLDL) are created and released from the liver into the circulation. What is the first thing that happens to them in the capillaries?
1 - processed into LDL
2 - more throughout blood for lipoprotein lipase to digested TAGs and release fatty acids
3 - processed in HDL
4 - move directly to adipose cells to deposit TAG and cholesterol
2 - more throughout blood for lipoprotein lipase to digested TAGs and release fatty acids
- lipoprotein lipase is released from capillaries
- TAG and fatty acids are released from VLDL and absorbed by capillaries
In endogenous lipid transport once very low density lipoproteins (VLDL) have had most of their TAGs absorbed by capillaries, what do VLDL become?
1 - chylomicrons
2 - intermediate lipoproteins (IDL)
3 - LDL
4 - HDL
2 - intermediate lipoproteins (IDL)
In endogenous lipid transport what happens to the intermediate lipoproteins that are formed from VLDL?
1 - repackaged in liver to HDL
2 - repackaged in liver to VLDL
3 - repackaged in liver to LDL
4 - repackaged in liver to bile acids
3 - repackaged in liver to LDL
In endogenous lipid transport what happens to low density lipoproteins (LDL)?
1 - transport TAGs throughout the body
2 - transport cholesterol to the body
3 - transport cholesterol from body to liver
4 - transport TAGs and cholesterol from the GIT to the liver
2 - transport cholesterol to the body
- LDLs are transported to peripheries
- LDL receptors bind to LDL
- cholesterol is stored in tissues
What is the reverse pathway involved in lipid transport?
1 - remove excess TAGs from blood
2 - collect excess cholesterol and return it to the liver
3 - remove cholesterol from plaques
4 - distribute cholesterol around the body
2 - collect excess cholesterol and return it to the liver
- free cholesterol in tissues is absorbed by HDL
- HDL transport cholesterol to liver for processing
Out of the 5 main lipoproteins:
- chlylomicrons
- VLDL
- IDL
- LDL
- HDL
Which has the highest cholesterol and TAG content?
- VLDL = highest TAG content
- LDL = highest cholesterol content
Primary dyslipidaemia is a dysfunction in lipid metabolism that causes elevated lipid profile. What is the cause of primary dyslipidaemia?
1 - abnormality of lipoprotein metabolism
2 - excess cholesterol intake
3 - excess synthesis of cholesterol by the liver
4 - all of the above
1 - abnormality of lipoprotein metabolism
- generally due to genetics
- abnormal enzymes, abnormal lipoprotein structure or lack of or dysfunctional lipoprotein receptors
Which of the following are causes of primary dyslipidaemia?
1 - abnormal enzymes
2 - abnormal lipoprotein structure
3 - lack of or dysfunctional lipoprotein receptors
4 - all of the above
4 - all of the above
What is the Frederick classification?
1 - classification of arrhythmias
2 - classification of hypertension
3 - classification of heart failure
4 - classification of dyslipidaemia
4 - classification of dyslipidaemia
Which of the following is NOT a key characteristic of type I familial hyperchylomicroanaemia, according to the Frederick classification?
1 - low chylomicrons
2 - primary cause lipoprotein lipase
3 - normal cholesterol
4 - high TAGs
1 - low chylomicrons
- associated with high chylomicrons as per the name
Which of the following is NOT a key characteristic of type IIa familial hypercholesterolaemia, according to the Frederick classification?
1 - high LDL
2 - primary cause lipoprotein lipase
3 - normal, or slightly raised TAGs
4 - high cholesterol (>5mmol/L even at birth)
2 - primary cause lipoprotein lipase
- primary cause is LDL receptors on tissues
- there is either none or very few
Are young patients with type IIa familial hypercholesterolaemia at risk of atherosclerosis?
- yes
- HIGH RISK of atherosclerosis
- need aggressive treatment
What type of inheritance is hypercholesterolaemia type IIa?
1 - autosomal (non sex chromosome specific) dominant
2 - autosomal recessive
3 - X linked dominant
4 - X linked recessive
1 - autosomal (non sex chromosome specific) dominant
- 1 inherited gene = bad
- 2 inherited genes = really bad
How common is familial hypercholesterolaemia type IIa?
1 - 0.5% of population
2 - 10% of population
3 - 20% of population
4 - >35% of population
1 - 0.5% of population
Which of the following is NOT a key characteristic of type IIb familial combined hyperlipidaemia, according to the Frederick classification?
1 - high LDL and VLDL
2 - primary cause is high Apo B 100
3 - low TAGs
4 - high cholesterol
3 - low TAGs
- TAGs will be modernly raised
- metabolic syndrome is common in these patients as all bad lipids are high (VLDL, LDL and TAG)