Dyslipidaemia

Question 1

role of fat

Answer 1

growth and energy, synthesis of hormones and other substances

Question 2

body deposition of fat

Answer 2

in blood vessels, within organs which can cause blockage to blood flow and organ damage (Increased risk CVD)

Question 3

types of lipids

Answer 3

cholesterol, TAG, phospholipids

Question 4

cholesterol

Answer 4

found in membranes, brain, nerve cells and bile

Question 5

cholesterol role

Answer 5

production of bile salts, vitamin D synthesis, regulates membrane fluidity, production of oestrogen, testosterone and cortisol

Question 6

TAG

Answer 6

found in subcutaneous and visceral adipose tissue, in adipocytes

Question 7

role of TAG

Answer 7

energy source, cushioning of organs and provides protection around organs

Question 8

phospholipids

Answer 8

found in blood stream on surface of lipoproteins and cell membranes

Question 9

role of phospholipids

Answer 9

membrane fluidity, coating of nerves, used in signal transduction, make inflammatory compounds

Question 10

lipoproteins

Answer 10

associated with cholesterol and TAG in circulation

production and clearance dictates TAG and cholesterol levels

Question 11

chylomicrons

Answer 11

synthesised in enterocytes and secreted by lymph into circulation

80-90% TAG, 2% protein

Question 12

VLDL

Answer 12

synthesised in liver

55-65% TAG, 10% cholesterol, 5-10% protein

Question 13

LDL

Answer 13

formed when VLDL becomes lipid-depleted in circulation, can infiltrate and damage arteries (increases risk of atherosclerosis)

10% TAG, 50% cholesterol, 25% protein

Question 14

HDL

Answer 14

synthesised in liver but secreted as lipoprotein and forms in circulation by taking up other lipoproteins

5% TAG, 20% cholesterol, 50% protein

Question 15

chylomicron function

Answer 15

transport dietary TAG to tissues - muscles for use of energy and adipose for storage

Question 16

VLDL function

Answer 16

transport endogenous TAG

Question 17

HDL function

Answer 17

take excess cholesterol from peripheral tissues and delivers to the liver

Question 18

LDL function

Answer 18

transport cholesterol to peripheral tissues

Question 19

exogenous pathway of cholesterol and TAG transport

Answer 19

1. dietary lipids and cholesterol in intestine are absorbed into enterocytes and packaged into chylomicrons
2. chylomicrons go through lymph into blood vessels
3. at adipose and skeletal muscle the chylomicrons are lipolysed by lipoprotein lipase, which removes FA from TAG in lipoproteins
4. FA taken up by diffusion into tissue and the lipoproteins get smaller and smaller
5. results in chylomicron fragments (lipid depleted, cholesterol enriched) which is transported in blood to liver and taken up
6. cholesterol and TAG from chylomicron remnant are packaged into VLDL
7. liver can make glucose and cholesterol from TAG

Question 20

endogenous pathway of cholesterol and TAG transport

Answer 20

1. VLDL released from liver into blood stream
2. lipolysed at adipose and skeletal muscle by lipoprotein lipase to produce IDL and LDL
3. hepatic lipase at liver lipolyses IDL into LDL
4. LDL taken up by liver (receptor) and extra-hepatic tissues and liver use the cholesterol
5. reverse cholesterol transport - HDL synthesised from liver and transports cholesterol back to liver from peripheral tissues

Question 21

dyslipidemia

Answer 21

lipid levels too high

refers to high cholesterol, TAG, and low HDL cholesterol

Question 22

hypolipidemia

Answer 22

lipid levels too low

Question 23

risk factors for dyslipidemia

Answer 23

aging, various disorders, certain drugs, diet high in SFA, physically less active, overweight

Question 24

primary causes of dyslipidemia

Answer 24

genetic (hereditary) causes

familial combines hyperlipidemia, familial dysbetalipoproteinemia, familial hypercholesterolemia, familial hypertriglyceridema, hypoalphalipoproteinemia, lipoprotein lipase deficiency, apolipoprotein C2 deficiency

Question 25

secondary causes of dyslipidemia

Answer 25

lifestyle and other causes sedentary lifestyle with excessive dietary intake of total calories, saturated fat, cholesterol and trans fat diabetes mellitus, high alcohol consumption, chronic kidney disease, hypothyroidism, primary biliary cirrhosis, drugs (oral contraceptives, retinoids etc.)

Question 26

familial hypercholesterolemia

Answer 26

primary cause of dyslipidemia mutation of LDLr gene = high total cholesterol levels develop xanthomas along tendons, atherosclerosis

Question 27

xanthomas

Answer 27

cholesterol deposits

Question 28

atherogenic

Answer 28

ability to form atherosclerosis

Question 29

treatment of dyslipidaemia

Answer 29

lose weight, exercise, decreased saturated fat in diet, lipid-lowering drugs, LDL apheresis, treat other diseases that cause elevated lipids and monitoring

Question 30

cholesterol lowering strategies

Answer 30

major - replace saturated fat with unsaturated fats, increasing plant sterol intake to more than 1.5g/day other - losing weight, increasing soluble fibre intake, increasing soy protein

Question 31

components of heart healthy diet

Answer 31

oily fish, wholegrain breads and cereals, fruit and veg, nuts, low alcohol intake

Question 32

ideal total cholesterol

Answer 32

<5.5 mmol/L

Question 33

ideal LDL

Answer 33

<2.0 mmol/L

Question 34

ideal HDL

Answer 34

>1.0 mmol/L

Question 35

ideal TAG

Answer 35

<1.7