lipoproteins and lipid disorders Flashcards
Traditional Lipid panel
perfomed fasting to clear chylomicrons and remnants so only LDL, VLDL and HDL are present in circulation
Total cholesterol/HDL/TG (measured)
LDL- calculated (LDL=total-HDL-VLDL)
VLDL estimated form VLD=TG/5 (only if TG>400 mg/dl
Direct measured LDL
ApoB/ApoA1 ratio (apob only on chylomicrons VLDL IDL and LDL, apoA1 only on HDL A ONE is what you ONEnt
Two worst risk factors for an ischemic event
aging, and already has an ischemic event
Fredrickson phenotypic hyperlipidemia classification
type 1 (hyper chylomicron)- kinda rare, Tg are extremely high
type2 a (hyper cholesterolemia)- common, LDL is high Type 2 b( combined hyperlipidemia)- common LDL and VLDL is high, low HDL
Type 3 (dysbetalipoproteinemia)- rare Tc and Tg high
Type 4 VLDL (hyper TG) overporduction of VLDL–> increased TG and VLDL
Familial hyperchylomicronemia (Type 1) AR
lipoprotein Lipase, APOC 2 deficiency
youngs, TGs high, recurrent pancreatitis, xanthomas, lipemia retinalis,
Pancreatitis, hepatosplenomegaly, eruptive/prurititc xanthomas, no risk of atherosclerosis, creamy layer
Restrict Dietary TG
Familial hyc=percholesterolemia type 2 a
LDL R mutation
APo B 100 mutations, activating mutation of PCSK9
LDL cholesterol (190 - 400 mg/dl)
point mutations of LDL R, decreased clearance LDL by liver, early coronary artery diseaases, tendnois xanthomas
accelerated atherosclerosis, tendon xanthomas, corneal arcus
Type 2 b (elevated LDL and VLDL and hyperlipidemia
MOST common lipid disorder
increased LDL, VLDL, VLDL Tgs
major cause of ischemic heart disease,
Polygenic disorder
overproduction of Apo B100, HDL low
no tendinous xanthomas,
Type 3 hyperlipoproteinemia aka dysbetalipoproteinemia
Early CAD andPVD, really high cholesterol and TG, tuberoeruptive xanthomas
Homozzygous for the apo E, incomplete penetrance, decreased clearance of VLDL by liver, palmar crease xanthomas
Obesity, diabetes, hypothyroidsm, glucocorticoids, aging
Premature atherosclerosis, tuberoeruptive xanthomas, palmar xanthomas
Type 5 hyperlipidemia
elevation in chylomicrons and VLDL
TG elevation less severe than type one, >1000
complicated by pancreatitis, critical to identify exacerbating factors, acute pancreatitis and insulin resisitance
Monogenic causes of hyperlipidemias
Type 1 *chylomicronemia, and type 2a hypercholesterolemia
Lipoprotein lipase/C2 mutation
2 a- LDLR mutation –> apoB100 and activating PCSK9
type 3 for E2
Hypercholesterolemia secondoary causes
Hypothyroidism, nephrotic syndrome, obstructive liver disease, anabolic steroids, pregnancy
HyperTGemia exacerbating factors
T2DM/Obesity, Alcohol, Estrogens
Genetic very low HDL syndromes rare
under 5 mg/dl
APoA1 deficiency, Tangier disease(orange tonsils, cloudy cornea, CAD, splenomegaly, low HDL), LCAT deficiency (clowdy cornea, renal failure, no CAD, low LDL
