Cholesterol Flashcards
What causes unstable plaques
Full of lipids and inflammation
Define Lipids
Group of biological macromolecules that have a major hydrocarbon component and are not easily dissolved in water
What are the 3 main families of Lipids
Fatty acids
Steroids - Cholesterol, steroid hormones
Phospholipids
State some characteristics of dietary Fats
Major source of energy
Needed to absorb vitamins
Essential for cell membranes
Define Fatty acids
Glycerol molecule linked to 3 fatty acids
State the two types of fat and give examples of both
Saturated - beef and dairy fats: increase in CVD
Non saturated - plant and fish fats
State the chemical difference between the fats
Fats with no double bonds in the hydrocarbon chain are ‘saturated’
Fats that have double bonds with a kink are unsaturated
State some characteristics of steroids
Core structure of 4 fused carbon rings
Many hormones and vitamins are steroids
State some characteristics of Cholesterol
Produced by the human liver, about 1g a day
Dietary cholesterol only makes up 10% of serum cholesterol
Define Lipoproteins
Biochemical assembly which transports lipid molecules in blood and extracellular fluids
Define Apolipoproteins
Proteins that bind with lipids to form lipoproteins
How are lipoproteins differentiated
How they behave in a centrifuge:
VLDL - very low density lipoprotein
LDL
HDL
Describe the cycles of lipoproteins
- Triglycerides in VLDL and cholesterol in LDL caused atherosclerosis
- HDL is protective
- VLDL transformed into LDL, LDL transports cholesterol to cells, HDL removes excess cholesterol from cells, Liver converts HDL unto bile salts
- Liver has LDL receptors, if these are defective then LDL will be very high, can causes heart attacks v early
Which is good and bad, LDL or HDL
LDL is bad - transports cholesterol to the cells
HDL is good - removes excess cholesterol from cells
Define Homozygous Familial Hypercholesterolemia
2 mutant alleles
1 in 300,000
Total Cholesterol > 500
State some consequences of Homozygous Familial Hypercholesterolemia
Atherosclerosis and heart attacks in 40s
State some treatments of Homozygous Familial Hypercholesterolemia
Medication
Liver transplant
Experimental siRNA
Define Heterozygous Familial Hypercholesterolemia
One mutant allele
LDL over 190
State treatments of Heterozygous Familial Hypercholesterolemia
Satin drugs!
What was the seven countries studies
Major study that recognised that diet has a big effect on CHD
What were the Seven Countries Studies findings
CHD increases with blood cholesterol level
The higher your HDL, the lower the risk
Describe the inter heart study
Revealed that lipids were 50% of the population attributable risk
Describe Population attributable risk (PAR)
Is the incidence of a disease that would be eliminated if exposure to that incident was eliminated
What were the findings of the 4S study
Provided reductase evidence for satins - that no matter what satins helped, every study was positive
What were the findings of Clinical trials of satins
30% people discontinue Satins
61% take it after 3 months
55% take it after 6 months
State an alternative to Satins
PCSK9
Describe how the PCSK9 works
Binds to the receptor for LDL particles
If blocked than more LDL receptors recycled and are present of the surface of cells to remove LDL
State the major downside for PCSK9s
Costs thousands of dollars
Describe the findings of the cohort study on dietary cholesterol
Egg consumption was not independently associated with risk - limiting dietary cholesterol has unclear benefits
Class the different types of dietary fats
Bad - industrial made trans fat
Middle - Replacing saturated fats with polyunsaturated fats
Good - Monounsaturated fats; olive oil, nuts, avocado
Good - Polyunsaturated fats
What’s the general tip with plant oils?
Non tropical plant oils are good! Tropical plant oils not so much
What was the issue with diet studies and confounding
No single definition for Mediterranean diet - generally associated with lower mortality rate
