Complex Lipids Part 2

Formed through the metabolism of VLDL in circulation; lipid content, size, and density of IDL is intermediate between VLDL and LDL

Intermediate Density Lipoprotein

Not detectable in blood -> becomes LDL

Intermediate Density Lipoprotein

LDL variant with apo(a) linked to apoB-100 via disulfide bond

Lipoprotein (a)

Apo(a) is structurally similar to ?

PLASMINOGEN

Lipoprotein (a) migrates in what region in electrophoresis

pre-beta

>50mg/dL of Lipoprotein (a) = ?

Increased risk of cardiovascular diseases

Reference Range of TC

140-200 mg/dL

Reference Range of HDL-C

40-75 mg/dL

Reference Range of LDL-C

50-130 mg/dL

Reference Range of Triglycerides

60-150 mg/dL

Fasting for 10-12hrs does what to Chylomicrons?

ELIMINATES CHYLOMICRONS

What is the:

Ideal HDL in men:

Ideal HDL in women:

– Ideal HDL in men: >40mg/dL

– Ideal HDL in women: >50mg/dL

HDL value that has protective effect for both sexes

>60mg/dL

Diseases associated with abnormal lipid concentrations

DYSLIPIDEMIA

2 CATEGORIES OF DYSLIPIDEMIA

Hyperlipoproteinemias

Hypolipoproteinemias

3 SUBDIVISIONS OF HYPERLIPOPROTEINEMIA

• Hypercholesterolemia (LDL)

• Hypertriglyceridemia

• Combined hyperlipidemia (LDL and VLDL)

2 Subdivisions of Hypertriglyceridemia

• Exogenous hypertriglyceridemia (CM)

• Endogenous hypertriglyceridemia (VLDL)

• Most closely linked to heart disease (ATHEROSCLEROSIS)

• Increase in LDL-cholesterol

• Genetic abnormalities

Hypercholesterolemia

Normal synthesis of intracellular cholesterol but lack or have defective LDL receptors

FAMILIAL HYPERCHOLESTEROLEMIA

- Increased lipoprotein: LDL

- Increased lipid profile component: LDL, TC

FAMILIAL HYPERCHOLESTEROLEMIA

cholesterol deposits on the backs of the hands, knuckles and the Achilles tendon

Tendon xanthomas

cholesterol deposits on or around eyelids

Xanthelasma

cholesterol deposits in the cornea

Arcus senilis

– Defective or deficiency in Lipoprotein Lipase (LPL) or Apo-C2

Exogenous Hypertriglyceridemia /Hyperchylomicronemia

– Increased lipoprotein: CM only

– Increased lipid profile component: Very high TAG

Exogenous Hypertriglyceridemia /Hyperchylomicronemia

– Strongly associated with Obesity and DM 2

– Most common type of hyperlipoproteinemia

Endogenous Hypertriglyceridemia (VLDL)

– Increased lipoprotein: VLDL only

– Increased lipid profile component: TAG

Endogenous Hypertriglyceridemia (VLDL)

May result in recurrent ACUTE PANCREATITIS

HYPERTRIGLYCERIDEMIA

• Defect in Apo B-100

• Considered at increased risk of CHD

Combined Hyperlipidemia

• Increased lipoproteins: LDL, VLDL

• Increased lipid profile component: LDL, TC = TAG

Combined Hyperlipidemia

• Increased lipoproteins: VLDL, CM

• Increased lipid profile component: TAG >> TC

• Serum has milky/creamy top layer with underlying turbidity

Combined Hypertriglyceridemia

• Defective Apo E

Dysbetalipoproteinemia

• Increased lipoprotein: IDL, Chylomicron Remnant

• Increased lipid profile component: TC, TAG

Dysbetalipoproteinemia