Atherosclerosis

Question 1

Define atherosclerosis

Answer 1

The form of arteriosclerosis (i.e. Disease causing the thickening and loss of elasticity of arterial walls) which is characterized by the formation of a lipid and cholesterol laden mass in the intima or media of large and medium sized arteries

Question 2

Define dyslipidaemia

Answer 2

Elevated total or low density lipoprotein (LDL) cholesterol levels, or levels of high density lipoprotein (HDL) cholesterol

Question 3

Cut offs for dyslipidaemia

Answer 3

• elevated total-chol >5.2mmol/L
• elevated LDL-chol >3.4mmol/L
• elevated triglyceride >1.7mmol/L
• depressed HDL-chol <1.0mmol/L

Question 4

Atherosclerotic process stages

Answer 4

1) endothelial dysfunction/infiltration of LDL intima
2) modification (oxidisation) of LDL-migration of monocytes
3) macrophages engulf ox-LDL - foam cell formation
4) SMC migration/proliferation - extra cellular matrix degradation
5) plaque rupture/thrombosis

Question 5

What are the anti-atherogenic effects of endothelium-derived NO

Answer 5

• vasodilation
• ⬇️ shear and pressure
• ⬇️ platelet aggregation and adhesion
• ⬇️ monocyte adhesion and macrophage transformation
• ⬇️ smooth muscle cell proliferation, transmigration
• ⬇️ superoxide anions, ox-LDL and foam cell formation

Question 6

How much of heart disease is attributed to high cholesterol?

Answer 6

1/3 of global heart disease is attributable to high cholesterol (WHO)

Question 7

Effect of exercise on cholesterol levels

Answer 7

• ⬆️ HDL-C
• ⬇️ TC and LDL-C less frequent
• longer stimulus and/or dietary intervention may be needed for LDL and TC reduction
• exercise more effective in subjects with high total cholesterol levels
• exercise duration most important part of prescription

Question 8

How might exercise prevent atherosclerosis progression?

Answer 8

• exercise stimulus for NO release
• NO has anti-atherogenic properties
• training significantly increases NO-mediated endothelial function especially in subjects with risk factors and CV diseases

Question 9

Effects of statins on exercise capacity

Answer 9

• can induce myalgia/myopathies
• statin-induced myalgia worsened by exercise
• statin may block aerobic training response