What is the cause of the abdominal pain in hypertriglyceridemias?
TGs > 1000 cause pancreatitis.
What is the incidence of chylomicronemia?
What is the incidence of familial hypercholesterolemia?
About 1-2 in a million.
About 1 in 500 (Autosomal Dominant >> Heterozygotes have disease phenotype)
What are the skin lesions seen in dyslipidemias/hypercholesterolemias?
Fatty deposits, "xanthomas".
What enzymatic defects can cause hyperchylomicronemia?
What other lipoprotein particles may be involved?
LPL, ApoCII, ApoCIII (gain of function).
Why is chylomicronemia equated with hypertriglyceridemia here?
What measures can be used to reduce serum triglycerides?
Chylomicrons are largely triglycerides by composition.
Fibrates > Niacin > Omega-3 Fatty acids. Diet, exercise, weight loss.
Recall the physiology of atheroma formation.
Are old or new atheromas more dangerous?
Endothelial cells & macrophages oxidize LDLs. Smooth muscle cells migrate to the Tunica Intima & proliferate.
Old atheromas are stable & fibrous, new atheromas are more inflammatory and more susceptible to thrombus/embolus formation.
A patient presents with elevated LDLs (>200) but has no other risk factors and is otherwise healthy & active.
What is her risk of CVD? What treatment should you recommend?
Why aren't Types IIb/III/IV hypercholesterolemias on the differential?
This is characteristic of FH; her risk of CVD is markedly elevated and treatment with statins is indicated immediately.
IIb/III/IV are also associated with elevated TGs, which are absent here.
Name 3 possible defects which can cause familial hypercholesterolemia.
If the defect is an LDL receptor mutation, why are statins still indicated?
Mutation in LDL receptor, in PCSK9 (gain of function?), or in ApoB-100.
Most of these patients are heterozygous, and therefore still express some functional LDLr, and would benefit from statins.
For most patients who need to be placed on statins, treatment continues for the patient's lifetime.
Why might a FH patient be taken briefly off of statins?
FH patients are started on statins early in life; if they were to become pregnant, statins would be contraindicated.
(a typical statin patient is older & not considering pregnancy)
Is the average American patient recommended for statins?
Probably. The average american is borderline for several of the criteria for metabolic syndrome, which increases ASCVD risk.
Recall the following normal lab values:
Fasting Blood Sugar
TC: <200 mg/dL
LDL: <130 mg/dL (roughly)
HDL: >50 mg/dL (depends on gender)
TGs: <150 mg/dL
FBS: <100 mg/dL
What is the leading cause of death in America?
How does it compare to, say, Breast cancer?
Cardiovascular heart disease.
Women are 8x more likely to die from CVD than breast cancer.
What are the criteria for metabolic syndrome classification?
Waist > 40in men / 35in women (Asian: 35/32in)
TGs > 150
HDL < 40 men / 50 women
BP > 135/85
FBG > 100