Hyperlipidaemia Flashcards
What amount of total cholesterol gives a mild risk of CHD?
5.2-6.5 mMol/L
What is hyperlipidaemia?
Raised plasma cholesterol and raised plasma triacylglycerol
What amount of total cholesterol gives a medium risk of CHD?
6.5-7.8mMol/L
What amount of total cholesterol gives high risk of CHD?
> 7.8 mMol/L
What amount of LDL cholesterol gives a mild risk of CHD?
3.5-4.5 mMol/L
What amount of LDL cholesterol gives a medium risk of CHD?
4.5-5.5 mMol/L
What amount of LDL cholesterol gives a high risk of CHD?
> 5.5 mMol/L
What amount of HDL cholesterol gives a medium/high risk of CHD?
<1.1 women
What total TAG amount gives a mild risk of CHD?
<2
What total TAG amount gives a medium risk of CHD?
> 2
What total TAG gives a high risk of CHD?
> 5
What are some secondary causes of hyperlipidaemia?
Diabetes type 2, hypothyroidism, obesity, alcohol abuse, renal failure, pregnancy
What are the classifications of hyperlipoproteinaemias?
Phenotype (symptoms), genotype (molecular defects)
How to measure traditional classification?
-Serum/plasma cholesterol, lipoprotein electrophoresis, if possible separation of VLDL by ultracentrifugation, HDL by precipitation, total cholesterol - VLDL - HDL = LDL cholesterol, presence of xanthomas
In electrophoresis, how is this preformed and what would the plate look like?
Take plasma sample, put on gel and lipid stain it
First is chylomicrons because they are too big to get past into the gel.
Then LDL in the beta position, IDL, then VLDL in the pre-beta position and HDL in the alpha position.
What does beta- VLDL contain?
apoB48 and B100
What are xanthomas?
- rich in foam cells (resembling those in atherosclerosis)
- yellow or orange plaques or nodules
- occasionally associated with other diseases and must therefore be used together with plasma lipids to diagnose hyperlipidaemia.
What happens in disorder of lipoprotein lipase activity (type 1)?
- increase I’m chylomicrons
- lack of lipoprotein lipase activity
- type 1a: lipase not produced
- type 2b: ApoCII not produced
What does the lipoprotein lipase/ ApoCII interaction look like?
Enzyme is produced in the muscle or adipose tissue and anchors itself to walls. Chylomicrons come floating past and is anchored and starts to break down the chylomicron.
What are the similarities between type IV and V?
Both increase production of VLDL by liver.
Don’t understand the difference between IV and V but may be associated with apoE4 phenotype.
What does familial hypercholesterolaemia (type IIa) do?
Increased LDL
in most cases LDL receptors either absent of defective
What is type IIa heterozygote?
- 1:500 people
- 1 defective gene
- half normal number of receptors
- 2-3 fold increase in LDL
- CHD: if left untreated
- men: can develop in 30s common in 40s, by 60 85% will have had a heart attack, 50%
- women: CHD develops 10 years later despite similar LDL levels
What is type IIa homozygote?
- 1:1,000,000
- 2 defective genes
- no functional receptors
- 6 fold increase in LDL
- CHD
- symptoms seen from 2 years. Heart attack common in teens.
- death usually before 30 years
What are the treatments of type IIa homozygote?
Plasmapheresis, LDL apheresis, liver transplant, gene therapy
