L12-13 Lipids Flashcards
When is it appropriate to perform cardiac related screening in children (<20)? What is screened for?
Cholesterol levels - identify familial hypercholesterolaemia based on family history
When is it appropriate to perform cardiac related screening in young adults? What is screened for?
Cholesterol levels - when at high risk of heart disease based on known risk factors (obesity, diabetes, family history, smoking etc.)
Why are adults over 50 screened for cardiac related issues? What is screened for?
Routine screening needed as it is the leading cause of death
Heart disease, diabetes
According to the Joint British Societies (JBS), who are the groups to focus on in terms of prevention of cardiac related health issues?
Those with established disease, diabetes, or are healthy but at high risk of heart attack.
What techniques are used to carry out risk assessment for cardiac disease?
Lipid profile most important
Also ECG/imaging
What are the main measures in a lipid profile?
Cholesterol, triglycerides, HDL-cholesterol, and LDL-cholesterol
What test can be used to measure risk of developing cardiovascular disease?
What areas of the reference range indicate risk of cardiac issues?
High sensitivity C-reactive protein (hsCRP)
High end of the normal range increases risk
why test needs to be sensitive
Why can it sometimes be useful to know lipoprotein A levels in relation to cardiac disease?
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
What is the difference between primary and secondary hyperlipidaemia?
Secondary is due to presence of underlying condition
Primary is in absence of underlying condition
What is the Fredrickson classification system used to define?
What are the limitations of this system?
Types of primary lipid disorders
Doesn’t include secondary hyperlipidaemia and dyslipidaemias associated with metabolic syndrome
What are the two broad causes of secondary hyperlipidaemia?
Metabolic and drug related
Give 3 examples of metabolic causes of secondary hyperlipidaemia and how they produce this effect
Hypothyroidism - increased cholesterol, sometimes TAG
T2 diabetes - high triglycerides and FAs
Alcohol abuse - high triglycerides and FAs
Obesity - high triglycerides and FAs
Give 3 examples of drug related causes of secondary hyperlipidaemia
Beta blockers, corticosteroids, immunosuppressants
What is familial hypercholesterolaemia?
Defect in LDL receptor means less LDL is taken up, increasing cholesterol levels
How is familial hypercholesterolaemia diagnosed?
High cholesterol or LDL-C
And either tendon xanthomas (cholesterol deposits) or relative with condition
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?
Family history of MI - <50 in 2nd degree relative, <60 in 1st
Or high cholesterol (enough to be diagnosed with FH) in relative
What is familial defective apoB?
What condition is this clinically similar to?
A mutation in apolipoprotein B means it cant readily bind to LDL receptors, increasing LDL
Similar to familial hypercholesterolaemia (apoB is part of LDL)
What is polygenic or non-familial hypercholesterolaemia caused by?
Unknown genetic cause
Saturated fat, trans-fat, and cholesterol intake can have an effect
What can cause low blood HDL levels?
Insulin resistance, inflammation, liver disease, drugs (e.g. androgens and progestogens)
What are the three general genetic causes of familial low HDL disorders?
Mutations in ApoA1, ABC A1, and LCAT
What is hypertriglyceridaemia?
High blood triacylglyceride (TAG) levels
What is a better predictor of coronary artery disease, HDL levels or TAG levels? Why is this?
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
What type of molecule does TRL stand for and what is its relationship to atherogenic (fatty deposits in arteries) potential?
Triglyceride rich lipoproteins
Size of the particle is inversely proportional to atherogenic potential
What condition is caused by high levels of chylomicrons in the blood?
Acute pancreatitis
What does familial combined hyperlipidaemia present as?
Increase in LDL or TRL or both
Combined increase in cholesterol and TAG
What is the main cardiac biomarker used and why?
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
