Hyperlipidemia

Question 1

What is Hyperlipidemia

Answer 1

abnormal high levels of lipids/ lipoproteins in blood
aquired or genetic
can lead to atherosclerosis

Question 2

Lipid transport

Answer 2

carried in protein vesicles called lipoproteins

Question 3

difference between VLDL and LDL

Answer 3

VLDL carries triglycerides
LDL carries Cholesterol

Question 4

2 types of lipid metabolic pathways

Answer 4

Exogenous and Endogenous pathway

Question 5

Exogenous pathway

Answer 5

lipids broken down into chylomicrons in intestine
chylomicrons go to peripheral tissue
Triglyceride (TG) broken down by lipoprotein lipase to release fatty acid to be used by muscles
chylomicrons remenants form and taken up by liver to form HDL

Question 6

endogenous pathway

Answer 6

VLDL formed in liver from TG and cholesterol esters
TG in VLDL metabolised in muscles by lipoprotein lipase to release fatty acid and IDL
IDL metabolised to LDL to use in LDL receptors

Question 7

atherosclerosis

Answer 7

accumulation of lipids and cholesterol in artery walls
narrows blood vessels so less blood and oxygen reach vital organs
plaque can build up to further narrow vessels
can cause heart attack or stroke

Question 8

causes of hyperlipidemia

Answer 8

primary: familial/gene mutation affecting TG,HDL and LDL
secondary: lifestyle, diet, diabetes, kidney disease, alchohol/smoking, liver disease

Question 9

types of hyperlipidemia

Answer 9

hypercholesterolemia- increase in cholesterol
hypertriglyceridemia- increase in TG
combined hyperlipidemia - increase in cholesterol and TG

Question 10

symptoms of hyperlipidemia

Answer 10

usually no obvious symptoms
can lead to atherosclerosis or stoke
yellow skin lesions made of cholesterol-rich (eruptive) xanthomas appear on skin
high level of LDL/ hypercholesterolemia- xanthomas at multiple joints
high levels of TG/ hypertriglyceridemia- more xanthomas
Xanthelasma- yellow cholesterol plaques around eyelids

Question 11

phyisical signs of dyslipidemia

Answer 11

-primary: serum total cholesterol>240mg/dL
premature/ family history of cardiovascular disease
-secondary: liver enzymes, urinary protein, fasting glucose

Question 12

normal levels of lipids(mg/dL)

Answer 12

total cholesterol<200
LDL cholesterol<100
TG<150
HDL>60

Question 13

familial hypercholesterolemia

Answer 13

genetic disorder(autosomal dominant)
high cholesterol levels
cause by mutation in LDLR which means there is more LDL in circulation than normal
homozygous more severe than heterozygous

Question 14

5 classes of FH from LDLR

Answer 14

1) no LDLR synthesis
2)no LDLR transport from ER to golgi
3)no LDLR to LDL binding on cell surface
4)no LDLR-LDL internalization
5)no LDLR recycling back to cell surface

Question 15

mutation in PCSK9 gene

Answer 15

causes gain in function of PCSK9 protein
this causes LDL recptors to be broken down quicker so less recptors to accept LDL which means high cholesterol levels

Question 16

treatment

Answer 16

lifestyle changes- diet, exercise, smoking, alcohol
for high LDL- statins PCSK9 inhibitors and acid bile sequestrant
for high TG- niacin, fibrates, omega 3 fatty acids