10 - Lipid Disorders Flashcards
What are some primary disorders of lipoprotein metabolism?
- Hypercholesterolemia (hyperC)
- Hypertriglyceridemia (hyperT)
- Mixed hyperC and hyperT
What are some secondary disorders that can cause problems w/ lipoprotein metabolism?
- Diabetes
- Hypothyroidism
- Renal disease
- Liver disease
- Alcoholism
- Some drugs
What is the normal level of cholesterol and LDL?
- Cholesterol = less than 200
- LDL = less than 100
What is considered borderline high and high cholesterol?
- Borderline = 200-239
- High = over 240
What is considered borderline high and high LDL?
- Borderline = 130-159
- High = over 160
What is the consequence of hyperlipoproteinemia?
Atherosclerosis
What are the stages of atherosclerotic plaque formation?
- Liver produces VLDL, which is converted to IDL, then LDL
- LDL is oxidized and then taken up by macrophages
- Forms foam cells and fatty streaks which accumulate and form fibrous plaques
- Causes atheromatous ulcers and thrombosis
What is another name for LDL oxidation?
Lipid peroxidation
Will dietary cholesterol control work to prevent atherosclerosis in a px that doesn’t have hypercholesterolemia?
No, px must have hypercholesterolemia for dietary control to work
What is the function of bile acid sequestrants?
Bind bile in GI and disrupt enterohepatic circulation, decreasing and preventing reabsorption
Which drugs are bile acid sequestrants?
- Cholestyramine
- Cholestipol
- Colesevelam
How do bile acid sequestrants lower LDL?
- Reduce feedback inhibition of 7 alpha-hydroxylase by bile salts
- More cholesterol is catabolized into bile acids, which are mostly excreted in feces
- Expression of liver LDL receptors is increased so that liver can get more cholesterol from plasma LDL
- Plasma LDL levels drop
What are statins? What do they result in?
- HMG-CoA reductase inhibitors
- Lower cholesterol production, leading to lower plasma LDL levels
How are statins eliminated?
Biliary/fecal
Are statins reversible?
Yes