Cholesterol

Question 1

What causes unstable plaques

Answer 1

Full of lipids and inflammation

Question 2

Define Lipids

Answer 2

Group of biological macromolecules that have a major hydrocarbon component and are not easily dissolved in water

Question 3

What are the 3 main families of Lipids

Answer 3

Fatty acids
Steroids - Cholesterol, steroid hormones
Phospholipids

Question 4

State some characteristics of dietary Fats

Answer 4

Major source of energy
Needed to absorb vitamins
Essential for cell membranes

Question 5

Define Fatty acids

Answer 5

Glycerol molecule linked to 3 fatty acids

Question 6

State the two types of fat and give examples of both

Answer 6

Saturated - beef and dairy fats: increase in CVD
Non saturated - plant and fish fats

Question 7

State the chemical difference between the fats

Answer 7

Fats with no double bonds in the hydrocarbon chain are ‘saturated’
Fats that have double bonds with a kink are unsaturated

Question 8

State some characteristics of steroids

Answer 8

Core structure of 4 fused carbon rings
Many hormones and vitamins are steroids

Question 9

State some characteristics of Cholesterol

Answer 9

Produced by the human liver, about 1g a day
Dietary cholesterol only makes up 10% of serum cholesterol

Question 10

Define Lipoproteins

Answer 10

Biochemical assembly which transports lipid molecules in blood and extracellular fluids

Question 11

Define Apolipoproteins

Answer 11

Proteins that bind with lipids to form lipoproteins

Question 12

How are lipoproteins differentiated

Answer 12

How they behave in a centrifuge:
VLDL - very low density lipoprotein
LDL
HDL

Question 13

Describe the cycles of lipoproteins

Answer 13

1. Triglycerides in VLDL and cholesterol in LDL caused atherosclerosis
2. HDL is protective
3. VLDL transformed into LDL, LDL transports cholesterol to cells, HDL removes excess cholesterol from cells, Liver converts HDL unto bile salts
4. Liver has LDL receptors, if these are defective then LDL will be very high, can causes heart attacks v early

Question 14

Which is good and bad, LDL or HDL

Answer 14

LDL is bad - transports cholesterol to the cells
HDL is good - removes excess cholesterol from cells

Question 15

Define Homozygous Familial Hypercholesterolemia

Answer 15

2 mutant alleles
1 in 300,000
Total Cholesterol > 500

Question 16

State some consequences of Homozygous Familial Hypercholesterolemia

Answer 16

Atherosclerosis and heart attacks in 40s

Question 17

State some treatments of Homozygous Familial Hypercholesterolemia

Answer 17

Medication
Liver transplant
Experimental siRNA

Question 18

Define Heterozygous Familial Hypercholesterolemia

Answer 18

One mutant allele
LDL over 190

Question 19

State treatments of Heterozygous Familial Hypercholesterolemia

Answer 19

Satin drugs!

Question 20

What was the seven countries studies

Answer 20

Major study that recognised that diet has a big effect on CHD

Question 21

What were the Seven Countries Studies findings

Answer 21

CHD increases with blood cholesterol level
The higher your HDL, the lower the risk

Question 22

Describe the inter heart study

Answer 22

Revealed that lipids were 50% of the population attributable risk

Question 23

Describe Population attributable risk (PAR)

Answer 23

Is the incidence of a disease that would be eliminated if exposure to that incident was eliminated

Question 24

What were the findings of the 4S study

Answer 24

Provided reductase evidence for satins - that no matter what satins helped, every study was positive

Question 25

What were the findings of Clinical trials of satins

Answer 25

30% people discontinue Satins

61% take it after 3 months
55% take it after 6 months

Question 26

State an alternative to Satins

Answer 26

PCSK9

Question 27

Describe how the PCSK9 works

Answer 27

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

Question 28

State the major downside for PCSK9s

Answer 28

Costs thousands of dollars

Question 29

Describe the findings of the cohort study on dietary cholesterol

Answer 29

Egg consumption was not independently associated with risk - limiting dietary cholesterol has unclear benefits

Question 30

Class the different types of dietary fats

Answer 30

Bad - industrial made trans fat
Middle - Replacing saturated fats with polyunsaturated fats
Good - Monounsaturated fats; olive oil, nuts, avocado
Good - Polyunsaturated fats

Question 31

What’s the general tip with plant oils?

Answer 31

Non tropical plant oils are good! Tropical plant oils not so much

Question 32

What was the issue with diet studies and confounding

Answer 32

No single definition for Mediterranean diet - generally associated with lower mortality rate