Dyslipidemia

Dyslipidemia

Blood lipid levels outside the normal range.
Physiology fx of lipids and transportation
Diet, life style, genetics effects on the lipid blood levels

Lipids are sparingly soluble molecules that include cholesterol, fatty acids, and their derivatives.

Plasma lipids are transported by lipoprotein particles composed of proteins called apolipoproteins, and phospholipids, cholesterol esters, and triglycerides.

• Fatty acids from TG broken down to produce ATP as cellular energy.
• Cholesterol is a building block (membrane stiffeners )
• Precursor for :
? Steroid hormones
? Vit D
? Bile acids

Human plasma lipoproteins :
Classifications:
Chylomicrons (least dense)
Very-low-density lipoproteins (VLDLs)
Intermediate-density lipoproteins (IDLs)

Low-density lipoproteins (LDLs)
High-density lipoproteins (HDLs)

A sixth class, lipoprotein(a) [Lp(a)](resembles LDL in lipid composition and has a density that overlaps LDL and HDL)

VLDL typically inversely proportional to HDL

LDL transfer cholesterol from liver to periph. Tissue

HDL return back cholesterol from periph. tissue to liver






Physical Properties of Plasma Lipoproteins

Lipoprotein Lipid Composition Origin Apolipoproteins
Chylomicrons TG, 90%; chol, 3% Intestine B-48; C-I, C-II, C-III; E
VLDL TG, 55%; chol, 20% Liver B-100; C-I, C-II, C-III; E
IDL TG, 30%; chol, 35% Metabolic product of VLDL B-100; C-I, C-II, C-III; E
LDL TG, 10%; chol, 50% Metabolic product of IDL B-100
HDL TG, 5%; chol, 20% Liver, intestine A-I, A-II, A-IV; C-I, C-II, C-III; E
Lp(a) TG, 10%; chol, 50% Liver B-100; Apo(a)


? Nearly 90% of patients CHD have some form of dyslipidemia.
? Most dyslipidemias are multifactorial in etiology (Genetic influences +diet, activity, smoking, alcohol use, + comorbid conditions such as obesity and DM.

Cholesterol level :
1. 10 hrs fasting
2. Total serum TG reflect TG in VLDL
3. Total serum C reflect C in the HDL & LDL (neglect in VLDL)

Amount of TG in blood determined by:
• Genetic (absorption , synthesis, ability to synthesis
• Metabolism
• Dietary consumption (alcohol, estrogen)