hyperlipoproteinemia type 4

Etiology

• familial form
• secondary form
  • often associated with obesity &/or glucose intolerance
  • alcohol abuse
  • oral estrogen/progesterone-containing contraceptives

Epidemiology

• common
• most common form of hypertriglyceridemia
• patients may fluctuate between types 4 & 5

Pathology

• excess in apolipoprotein C3
• inhibits lipoprotein & hepatic lipase

Genetics

• generally autosomal recessive

Laboratory

• elevated serum triglycerides & VLDL
• normal serum cholesterol
• HDL-cholesterol is often low

Management

• correct precipitating causes
  • obesity
  • diabetes
  • alcohol
  • oral contraceptives
• most patients with familial forms are very sensitive to calorie restriction
• use of anti-hyperlipidemic agents is rarely necessary
  • fibrates are most commonly used
  • niacin may be used if fibrate plus diet is unsuccessful
  • large doses of fish oil have been used (6-8 g/day)

More general terms

• hyperlipoproteinemia (HLP)
• lipid metabolism, inborn error; lipid storage disease; lipidosis

Additional terms

• apolipoprotein C3; apo-CIII (APOC3)
• fibrate
• nicotinic acid (niacin, vitamin B3, Niaspan)