Lipid pathologies Flashcards
What is the fate of lipids?
Fats that are either absorbed from foods or synthesized by liver
Where are trigs stored?
Triglycerides store energy in adipocytes & muscle cells
What is the role of cholesterol?
constituent of cell membranes, steroids, bile acids
How is cholesterol transported?
Most cholesterol is carried in LDL and HDL
How are most triglycerides transported?
transported in chylomicrons or VLDL
What are the 5 major classes of lipoproteins?
- Lipoproteins are divided into five major classes, based on density:
A. Chylomicrons
B. Very low-density lipoproteins (VLDL)
C. Intermediate-density lipoproteins (IDL)
D. Low-density lipoproteins (LDL)
E. High-density lipoproteins (HDL)
Define hyperlipidemia
A group of disorders characterized by an excess of serum cholesterol, especially excess LDL-C &/or excess triglycerides
What causes abnormal lipoprotein metabolism? What follows?
- Defects in lipoprotein synthesis, processing & clearance
- Accumulation of lipids in plasma & vessel endothelium
- High LDL & low HDL associated with increased risk for ASHD
What causes primary dyslipidemia/hyperlipoprooteinemia?
- Gene mutations
- Familial combined hypercholesterolemia most common primary
A. ↑ Triglycerides & cholesterol & ↓ plasma HDL-C
Are secondary or primary dyslipidemia/hyperlipoprooteinemia?
Secondary
What are the secondary causes of hyperlipidemia?
- DM
- Glycogen storage diseases
A. Genetic or acquired enzyme defic. disorders - Lipodystophies
A. Abn. or degenerative conditions of adipose tissue - Excessive steroid use
- ETOH
- OCP’s
- Renal Dz
- Hepatic dysfunction
- Hypothyroidism
- Cushing’s Syndrome
What is isolated hypercholesterolemia?
due mostly to high LDL
What is mixed dyslipidemia?
– high total or LDL cholesterol + high triglycerides
What is isolated hypertriglyceridemia?
inc trig
What is Low HDL cholesterol?
alone or w/ high total cholesterol or high triglycerides
What is the epidemiology for lipid pathologies?
- T chol & LDL-C levels are similar in whites and blacks
- Trig lower & HDL-C levels higher in African-Americans
- Asian-Indians have the highest risk
- Chinese have the lowest risk
- Europeans have intermediate risk
- Differences in lipid levels can be partly explained by dietary & lifestyle differences
What are the risk factors for lipid disorders?
- Habitual excessive alcohol use
- Obesity
- Lack of exercise
- M > W
- Ethnic groups adopting a ‘western’ lifestyle
What is the most typical sxs of lipid pathologies?
- Typically asymptomatic
A. Incidental diagnosis from routine blood work
What sxs are indicative of lipid pathologies?
1. Xanthelasmas A. Yellow plaques on medial aspect of eyelids 2. Arcus (Senilis) Corneae A. Onset <45 y/o B. White/gray ring around corneal margin 3. Eruptive xanthomas A. Subcutaneous nodules along tendons/ligaments 4. GI manifestations A. Pancreatitis