Lipoprotein disorders causes: Difference between revisions
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**Overproduction of substrates, including triglycerides and acetyl-CoA | **Overproduction of substrates, including triglycerides and acetyl-CoA | ||
**Decreased clearance of LDL | **Decreased clearance of LDL | ||
===Hyperlipoproteinemia type III=== | ===Hyperlipoproteinemia type III=== | ||
Revision as of 19:23, 22 October 2012
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Lipoprotein Disorders Microchapters |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Hyperlipidemia can occur as either a primary event or secondary to some underlying disease. The primary hyperlipidemias include chylomicronemia, hypercholesterolemia, dysbetalipoproteinemia, hypertriglyceridemia, mixed hyperlipoproteinemia, and combined hyperlipoproteinemia. Other diseases, such as diabetes mellitus, pancreatitis, renal disease, and hypothyroidism, can cause the secondary form.
Causes
Primary hyperlipidemia
Hyperlipoproteinemia type I
- Deficiency of lipoprotein lipase (LPL) or altered apolipoprotein C2
Hyperlipoproteinemia type II
Type IIa
- Familial hypercholesterolemia
- Sporadic (due to dietary factors)
- Polygenic
- Truly familial (as a result of a mutation in the LDL receptor gene on chromosome 19 (0.2% of the population), the apo B gene (0.2%) or the proprotein convertase subtilisin kexin 9 (PCSK9) gene (very rare))
Type IIb
- Familial combined hyperlipoproteinemia (FCH)
- Overproduction of hepatically-derived apo B-100 associated with VLDL
- Overproduction of substrates, including triglycerides and acetyl-CoA
- Decreased clearance of LDL
Hyperlipoproteinemia type III
This form is due to high chylomicrons and IDL (intermediate density lipoprotein). Also known as broad beta disease or dysbetalipoproteinemia, the most common cause for this form is the presence of ApoE E2/E2 genotype. It is due to cholesterol-rich VLDL (β-VLDL). Prevalence is 0.02% of the population.
Hyperlipoproteinemia type IV
This form is due to high triglycerides. It is also known as hypertriglyceridemia (or pure hypertriglyceridemia). According to the NCEP-ATPIII definition of high triglycerides (>200 mg/dl), prevalence is about 16% of adult population.[1]
Hyperlipoproteinemia type V
This type is very similar to type I, but with high VLDL in addition to chylomicrons. It is also associated with glucose intolerance and hyperuricemia.
- ↑ Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) Final Report. Circulation 2002; 106; page 3240