L12-13 Lipids

Question 1

When is it appropriate to perform cardiac related screening in children (<20)? What is screened for?

Answer 1

Cholesterol levels - identify familial hypercholesterolaemia based on family history

Question 2

When is it appropriate to perform cardiac related screening in young adults? What is screened for?

Answer 2

Cholesterol levels - when at high risk of heart disease based on known risk factors (obesity, diabetes, family history, smoking etc.)

Question 3

Why are adults over 50 screened for cardiac related issues? What is screened for?

Answer 3

Routine screening needed as it is the leading cause of death

Heart disease, diabetes

Question 4

According to the Joint British Societies (JBS), who are the groups to focus on in terms of prevention of cardiac related health issues?

Answer 4

Those with established disease, diabetes, or are healthy but at high risk of heart attack.

Question 5

What techniques are used to carry out risk assessment for cardiac disease?

Answer 5

Lipid profile most important

Also ECG/imaging

Question 6

What are the main measures in a lipid profile?

Answer 6

Cholesterol, triglycerides, HDL-cholesterol, and LDL-cholesterol

Question 7

What test can be used to measure risk of developing cardiovascular disease?

What areas of the reference range indicate risk of cardiac issues?

Answer 7

High sensitivity C-reactive protein (hsCRP)

High end of the normal range increases risk
why test needs to be sensitive

Question 8

Why can it sometimes be useful to know lipoprotein A levels in relation to cardiac disease?

Answer 8

It is similar to LDL-cholesterol, but does not change as easily
Can be used to target individuals that would benefit from more aggressive treatment

Question 9

What is the difference between primary and secondary hyperlipidaemia?

Answer 9

Secondary is due to presence of underlying condition

Primary is in absence of underlying condition

Question 10

What is the Fredrickson classification system used to define?

What are the limitations of this system?

Answer 10

Types of primary lipid disorders

Doesn’t include secondary hyperlipidaemia and dyslipidaemias associated with metabolic syndrome

Question 11

What are the two broad causes of secondary hyperlipidaemia?

Answer 11

Metabolic and drug related

Question 12

Give 3 examples of metabolic causes of secondary hyperlipidaemia and how they produce this effect

Answer 12

Hypothyroidism - increased cholesterol, sometimes TAG
T2 diabetes - high triglycerides and FAs
Alcohol abuse - high triglycerides and FAs
Obesity - high triglycerides and FAs

Question 13

Give 3 examples of drug related causes of secondary hyperlipidaemia

Answer 13

Beta blockers, corticosteroids, immunosuppressants

Question 14

What is familial hypercholesterolaemia?

Answer 14

Defect in LDL receptor means less LDL is taken up, increasing cholesterol levels

Question 15

How is familial hypercholesterolaemia diagnosed?

Answer 15

High cholesterol or LDL-C

And either tendon xanthomas (cholesterol deposits) or relative with condition

Question 16

If a patient does fit all diagnostic criteria for familial hypercholesterolaemia, what other factors can be taken into account to keep this condition a possibility?

Answer 16

Family history of MI - <50 in 2nd degree relative, <60 in 1st
Or high cholesterol (enough to be diagnosed with FH) in relative

Question 17

What is familial defective apoB?

What condition is this clinically similar to?

Answer 17

A mutation in apolipoprotein B means it cant readily bind to LDL receptors, increasing LDL

Similar to familial hypercholesterolaemia (apoB is part of LDL)

Question 18

What is polygenic or non-familial hypercholesterolaemia caused by?

Answer 18

Unknown genetic cause

Saturated fat, trans-fat, and cholesterol intake can have an effect

Question 19

What can cause low blood HDL levels?

Answer 19

Insulin resistance, inflammation, liver disease, drugs (e.g. androgens and progestogens)

Question 20

What are the three general genetic causes of familial low HDL disorders?

Answer 20

Mutations in ApoA1, ABC A1, and LCAT

Question 21

What is hypertriglyceridaemia?

Answer 21

High blood triacylglyceride (TAG) levels

Question 22

What is a better predictor of coronary artery disease, HDL levels or TAG levels? Why is this?

Answer 22

HDL - TAG levels are associated with CAD, but this is due to being strongly inversely related to HDL levels

TAG is also more variable in blood than HDL

Question 23

What type of molecule does TRL stand for and what is its relationship to atherogenic (fatty deposits in arteries) potential?

Answer 23

Triglyceride rich lipoproteins

Size of the particle is inversely proportional to atherogenic potential

Question 24

What condition is caused by high levels of chylomicrons in the blood?

Answer 24

Acute pancreatitis

Question 25

What does familial combined hyperlipidaemia present as?

Answer 25

Increase in LDL or TRL or both

Combined increase in cholesterol and TAG

Question 26

What is the main cardiac biomarker used and why?

Answer 26

Troponin - cardiac troponin has different sequence to skeletal muscle equivalents; cardiac specific

• Sensitive as normally at very low levels
• Can detect MI in cases where other biomarkers cant