Lipids Flashcards
(47 cards)
Cholesterol is found in all human cell membranes except:
RBC
Whats the name of proteins found on the surface of lipoproteins?
Apolipoproteins
What are some functions of apolipoproteins?
- Maintain structure
- Acts as ligands
- Act as co-factors
List some of the apolipoproteins and their functions:
- Apo A-1: protein for HDL
- Apo B-100: protein for VLDL, IDL, LDL, Lp(a_ and receptor ligand
- Apo C-II: lipoprotein lipase activator (found in chylomicrons)
- component of Lp(a), and plasminogen antagonist
What is the relevance of lipoprotein (a)?
A marker for CVD and has the apolipoprotein a
Sources of TAGs?
Liver synthesis and diet
List primary dyslipidemia disorders:
- mixed dyslipidemia
- familial hypertriglycerides
- lipoprotein lipase deficiency
- Apo C-II deficiency
List acquired conditions that lead to dyslipidemia:
- diabetes mellitus
- nephrotic syndrome
- hypothyroidism
- Alcohol
- Drugs (Estrogen, thiazides, b-blocker, corticosteroids, cyclosporine, HAART)
Is HDL-C or LDL-C predictor of CHD?
HDL-C
Functions of HDL?
- reverse transport of cholesterol
- prevents LDL oxidation (this is more atherogenic)
- inhibits endothelial cell adhesion molecules and platelet aggregation
What is dyslipidemia?
high cholesterol and/or elevated TAGs, or low HDL
True or False: primary dyslipidemia is a genetically determined?
True
What things will lead to consider a primary dylipidemia?
- anyone with, or family history of, premature onset coronary heart disease or stroke: Men <55, Women <65
- markedly total elevated cholesterol (>6.5-7.0 mmol/L, normal < 5.2)
- triglycerides (>4.0 mmol/L, normal < 1.4)
- very low HDL (< ~ 0.7 mmol/L, normal >0.9).
What is considered for atherosclerosis risks (major risks)?
- Age: Men >45; Women >55
- Elevated cholesterol level, esp. low density lipoprotein cholesterol (LDL-C)
- Low levels of high density lipoprotein cholesterol (HDL-C)
- Family history of premature atherosclerosis: first degree male relative <55, female relative <65
- Hypertension (high blood pressure) (even if controlled with medication)
- Diabetes
- Smoking: One or more cigarettes daily
What are some factors associated with increased atherosclerosis risks?
Obesity / Metabolic Syndrome Sedentary lifestyle High stress levels Elevated Triglycerides Elevated Lp (a) Elevated C-reactive protein Elevated Homocysteine Elevated Fibrinogen
True or False: Lifestyle changes (more PA, and low fat diet) is enough to maintain genetic dyslipidemia in check?
False: can only lower by 20%
List the CV risk calculators:
- Framingham
- Reynolds Risk Score (adss CRP level - marker of inflammation in vasculaure)
Who do we screen for CVD?
- Men and women at or over 40 yrs (or postmenopausal); and higher risk groups (FN and South Asians)
- smoker, hiv, showing signs of atherosclerosis, hypertensive disease of pregnancy
How do we screen for CVD?
- history, physical
- lipid panel (TC, LDL-C, HDL-C,, TG)
- non-HDL
- glucose
- eGFR
non-fasting lipids are acceptable now
What is the aim for statin treatment?
LDL-C less than 2mmol/L or greater than 50% reduction, or ApoB less than 0.8g/L or non-HDL-C less than 2.6 mmol/L
List the classes of lipid lowering drugs:
- Statins - HMG CoA reductase inhibitors
- Cholesterol absorption inhibitors
- Bile acid sequestrants
- Fibrates
- Nicotinic acids
- PCSK9 inhibitors
Give an example of cholesterol absorption inhibitor and its effects:
Ezetimide
Lowers LDL up to 18-25% and more if synergistically used with statins
What happens to cholesterol and fatty acids in enterocytes?
Fatty acids are used to esterify cholesterol with the help ACAT enzyme or used to create TAGs
These molecules are then incorporated in chylomicrons with apoB-48
How do bile acid sequestrants work and what are the side effects?
Bind and inhibit reabsorption of bile acids and this increases LDL-receptors in liver –> lowers LDL-C (15-30%)
Side effects:
- increase in TAGs (should not be used for those with hypertriglyceridemia)
- constipation/upset stomach
