Hyperlipidemia

Question 1

What is actually measured when assessing a patient’s lipid levels?

Answer 1

• Total cholesterol
• LDL-C
• HDL-C
• TG

Question 2

How is the LDL cholestrerol usually measured?

What is the formula called?

Answer 2

Friedewald Formula

Question 3

Give the equation for the Friedewald Formula

Answer 3

LDL-C = TotChol - HDL-C - TG/5

Question 4

What do patients have to do before getting a cholesterol level/ lipid measurement?
Why do they have to do this?

Answer 4

Fast

• Triglyceride level will be low
• This means an accurate LDL-C can be obtained using the formula

Question 5

Hyperlipidemia can be elevated levels of either what 3 things?

Answer 5

• Total cholesterol
• LDL
• Triglycerides

Question 6

What are the possible causes of secondary hyperlipidemia?

Answer 6

• Nephrotic syndrome (LDL)
• Alcoholism (TG)
• Pregnancy (TG>TC)
• Beta blockers (TG)
• HCTZ (TC, LDL, TG)

Question 7

What drugs can modestly increase lipid levels?

Answer 7

• Beta blockers (TG)

- HCTZ (TC, LDL, TG)

Question 8

What are the signs of significant hyperlipidemia?

Answer 8

• Xanthomas
• Tendinous Xanthoma
• Corneal arcus

Question 9

What are Xanthomas due to?

Where are they commonly found?

Answer 9

• Plaques of lipid-laden histiocytes

- Appear as skin bumps or on eyelids

Question 10

Where can Tendinous Xanthomas (lipid deposits in tendons) be found commonly?

Answer 10

Achilles

Question 11

When may corneal arcus be found?

Answer 11

Fundoscopy

Question 12

At what elevated levels of triglycrides would pancreatitis actually be seen?

Answer 12

> 1000

Question 13

What is the mechanism behind pancreatitis due to hypertriglyceremia thought be?

Answer 13

Increased chylomicrons in plasma

• Chylomicrons usually formed after meals and cleared
• May obstruct capillaries -> ischemia
• Vessel damage can expose triglycerides to pancreatic lipases
• Triglycerides breakdown -> free fatty acids
• Acid -> tissue injury -> pancreatitis

Question 14

What are the signs of type 1 dyslipidemia (Hyperchylomicronemia)?

Answer 14

• > 1000 TG
• Milk plasma appearence
• Increased chylomicrons
• Recurrent pancreatitis
• Hepatomegaly
• Xanthomas

Question 15

How is type 1 dyslipidemia (Hyperchylomicronemia) inherited?

Answer 15

AR

Question 16

What type 1 dyslipidemia (Hyperchylomicronemia) due to?

2 possible mechanisms

Answer 16

Severe LPL dysfunction

• LPL deficient
• LPL co-factor deficient (apolipoprotein C-II)

Question 17

What is the treatment for type 1 dyslipidemia (Hyperchylomicronemia)?

Answer 17

Very low fat diet

- Normal lifespan and no incr risk of stherosclerosis

Question 18

How is Type II familial dyslipidemia (Familial Hypercholesterolemia) inherited?

Answer 18

Aut Dominant

Question 19

What is thought to cause Type II familial dyslipidemia (Familial Hypercholesterolemia)?

Answer 19

Few or zero LDL receptors

Question 20

What are the clinical signs / lab findings in Type II familial dyslipidemia (Familial Hypercholesterolemia)?

Answer 20

• V. High LDL (>300 Heterozygote, >700 homozygote)
• Tendon xanthomas, corneal arceus
• Atherosclerosis, MI often in 20s

Question 21

What is Type III familial dyslipidemia (familial dysbetalipoproteinemia) due to?

Answer 21

Apo-E2 subtype of Apo-E

• Poorly cleared by liver
• Accumulation of chylomicron remnants and VLDL (collectively known as B-lipoproteins)
• Elevated cholesterol and triglycerides

Question 22

What will TC levels be in Type III familial dyslipidemia (familial dysbetalipoproteinemia)?

Answer 22

Usually mild TC >300mg/dL

Question 23

What will be seen in Type III familial dyslipidemia (familial dysbetalipoproteinemia)?

Answer 23

• Xanthmoas

- Premature coronary artery disease

Question 24

If you have ApoE2 allelle (Type III familial dyslipidemia) what are your chances of Alzheimers?

Answer 24

Decreased risk

Question 25

What is the risk of Alzheimers with an ApoE4 allelle?

Answer 25

Increased risk

Question 26

What is Type IV familial dyslipidemia (hypertriglyceridemia) due to?

Answer 26

- VLDL overproduction or impaired catabolism - Increased TG (200-500), not pancreatitis - Increased VLDL

Question 27

What is Type IV familial dyslipidemia (hypertriglyceridemia) associated with?

Answer 27

- Type II diabetes | - CVD, premature coronary disease

Question 28

What familial dyslipidemias are Aut Dominant?

Answer 28

- Type II: Familial Hypercholesterolemia | - Type IV: hypertriglyceridemia