Disorders of lipid metabolism/Questions and case studies

Questions

 * 1) Which of the following statements regarding LDL is true?
 * 2) * A – participates in the supply of triacylglycerols through peripheral tissue
 * 3) * B – the main component of the surface part is cholesterol esters
 * 4) * C – apolipoprotein C is needed for its function
 * 5) * D – this particle is removed from the circulation by receptor-mediated endocytosis
 * 6) Which of the following is not involved in esterification in centripetal cholesterol transport?
 * 7) * A – lecithin-cholesterol acyltransferase (LCAT)
 * 8) * B – phosphatidylcholine
 * 9) * C – apolipoprotein A
 * 10) * D – apolipoprotein B
 * 11) Squalene is an intermediate metabolite in the biosynthesis of:
 * 12) * A – cholesterol
 * 13) * B – β-hydroxybutyrate
 * 14) * C – unsaturated fatty acids
 * 15) * D – sphingomyelin
 * 16) * E – acylcarnitine
 * 17) The following does not apply to triacylglycerol hormone-sensitive lipase:
 * 18) * A – catalyzes the breakdown of triacylglycerols, which are transported in the core of VLDL particles
 * 19) * B – is induced by insulin
 * 20) * C – is regulated by phosphorylation and dephosphorylation
 * 21) * D – is an integral part of HDL
 * 22) What results from a complete lack of apolipoprotein B-48?
 * 23) * A – VLDL cannot be formed
 * 24) * B – chylomicrons cannot be formed
 * 25) * C – LDL particles cannot be formed
 * 26) * D – cholesterol synthesis in the liver is impaired
 * 27) Fatty acids released from adipose tissue are transported by circulation:
 * 28) * A – bound to albumin
 * 29) * B – as triacylglycerols carried by chylomicrons
 * 30) * C – as lecithin on the surface of HDL particles
 * 31) * D – by no specified mechanism
 * 32) Fatty acid catabolism stimulates gluconeogenesis in all of the following ways except:
 * 33) * A – by contributing to the production of NADH
 * 34) * B – by providing carbons for the glucose backbone
 * 35) * C – by activating pyruvate carboxylase
 * 36) * D – by contributing to the production of ATP
 * 37) Fatty acids serve as an energy source for (list all):
 * 38) * A – liver
 * 39) * B – brain
 * 40) * C – musculature
 * 41) * D – red blood cells
 * 42) Which statement about HDL is correct?
 * 43) * A – has an antiatherogenic effect
 * 44) * B – arise in adipose tissue
 * 45) * C – carry triacylglycerols in their nucleus
 * 46) * D – enable centripetal transport of cholesterol
 * 47) * E – in the circulation they transmit apolipoprotein E and C to chylomicrons
 * 48) The proliferation of LDL particles is more dangerous from the point of view of atherogenicity than the proliferation of chylomicrons or VLDL because:
 * 49) * A – LDL particles are smaller than VLDL or chylomicrons, so they penetrate the pores of the blood capillary wall and reach the target cells, to which they deliver cholesterol.
 * 50) * B – contain lecithin-cholesterol acyltransferase, which esterifies cholesterol into non-polar cholesteryl esters.
 * 51) * C – are taken up by target cells by endocytosis controlled by specific receptors
 * 52) * D – their increased amount in circulation stimulates the endogenous formation of cholesterol in the endothelium of vascular capillaries
 * 53) Why are VLDL particles increased in alcoholics?
 * 54) Which lipoprotein particles are increased in the absence of lipoprotein lipase?

Patient with hypertension and ischemic heart disease
A woman, 52 years old, with hypertension (controlled by medication), ischemic heart disease was examined for a lipid profile. The findings showed an increase in LDL-cholesterol (4.62 mmol/l), a decrease in HDL-cholesterol (0.90 mmol/l) and an increase in triacylglycerols (2.85 mmol/l). Her brother had mild hypercholesterolemia, but a significant decrease in HDL-cholesterol and normotriacylglycelemia, her sister had marked triacylglycerolemia.

Questions:
 * 1) What are the main risk factors for coronary heart disease?
 * 2) What adverse effect can poorly treated diabetes have on lipoprotein metabolism?
 * 3) What does oxidized LDL-particles cause?

Patient after acute myocardial infarction
A 53-year-old man who suffered an acute myocardial infarction was followed by the attending physician. Triacylglycerol level: 1.6 mmol/l, HDL-cholesterol: 0.89 mmol/l, cholesterol: 9.5 mmol/l, calculated LDL-cholesterol also significantly increased. His younger brother had a family history of "high cholesterol".

Questions:
 * 1) What is the most likely form of hyperlipoproteinemia in this patient?
 * 2) What is the mechanism of the therapeutic effect of cholestyramine (bile acid sequestrant) and statins?

A patient with hyperlipidemia
In a 65-year-old man, hyperlipidemia was discovered during a routine examination: cholesterol: 8.8 mmol/l, triacylglycerols: 2.4 mmol/l. The patient had periorbital edema, dry skin and hair, there was no family history of cardiovascular disease.

Questions: Note: the thyroid disorder must be treated primarily, hyperlipoproteinemia usually resolves.
 * 1) What can be the causes of combined hyperlipoproteinemia?
 * 2) What other examinations do you recommend for differential diagnosis?

Patient with xanthomas and hypercholesterolemia
A 55-year-old, obese woman came to the general practitioner with nodules about 2 cm in diameter on her forearm. She had yellowish streaks on her palms (palmar striae).

Laboratory examination:
 * cholesterol: 11,9 mmol/l
 * triacylglycerides: 8.7 mmol/l
 * ELFO of lipoproteins: broad β fraction

Questions:
 * 1) What type of hyperlipoproteinemia is it?

A 46-year-old manager on a preventive check-up
His father had a history of acute myocardial infarction at the age of 57, but he lived to be 79 years old. The patient is obese (104 kg, 175 cm), blood pressure 170/100 mmHg.

Laboratory examination: Questions:
 * cholesterol: 6,5 mmol/l
 * triacylglycerols: 2.9 mmol/l
 * HDL cholesterol: 0.84 mmol/l
 * 1) What are the health risks for this patient?

related articles

 * Lipids
 * Cholesterol
 * Atherosclerosis
 * CHD