Hyperlipidaemia and therapeutic approaches Flashcards
hyperlipidaemia
is the term used to denote raised serum levels of one or more of total cholesterol (Tchol), low density lipoprotein cholesterol (LDL-C), Triglycerides (TGs) or both Tchol and TG (combined Hyperlipidaemia)
dislipidaemia
is a wider term that also includes low levels of high density lipoprotein cholesterol (HDL-C)
chylomicrons
transport TGs/cholesterol from intestine indirectly (via lymph) to the blood.
Veyr ow density lipoproteins VLDL
(liver synthesised) have a high TG content. The capillary enzyme lipoprotein lipase converts the VLDLs TGs to free fatty acids, used for either energy [in muscle or liver] or storage [in adipose tissue].
low density lipoproteins LDL
contain a high cholesterol content.
high density lipoproteins HDL
absorb and transport peripherally-mobilised cholesterol from cell breakdown to the liver (protective).
what does the body use lipids for
Energy storage Intracellular signalling Extracellular mediators/signalling (lipoprotein) Base for steroid hormone synthesis Vitamin D synthesis Cell membranes
excess carbs converted to what
triglycerides and transported to fat cells
main site of sytnhteis of cholesterol
liver
higher TAG( triglycerides) lower cholesterol
choylomicorns sourced where
intestines
Dietary Lipids inc chol and FFA emulsified by bile acids & transported within chylomicrons to the liver
Then circulated as chol and triglycerides to disuse inVLDL
Endothelial lipoprotein lipase (LPL) liberate FFA in adipose and muscle for storage or metabolism
Resulting LDL return to hepatocytes via LDL receptors or taken up by LDL receptors in extrahepatic tissue where they are oxidised and contribute to atherogenesis
HDL pool derived from chylomicrons from action of LPL and reverse cholesterol pathways return HDL to liver vis HDL receptors
Hypercholesterolemia
Elevated LDL-C
Dyslipidemia
Includes elevated triglycerides and low HDL-C
serum total cholesterol, LDL-C, triglycerides, apolipoprotein B, or lipoprotein(a) concentration >90th percentile
HDL-C or apolipoprotein A-I concentrations <10th percentile
why is dyslipidemia important
Promotes atherosclerosis-cholesterol plaques
Ischemic heart disease
Cerebrovascular disease
Peripheral vascular disease
LDL-C normal range
1.8-2.6 -3.3
total cholesterol desirable range
under 5.2 optimal under 4.4