Understand the types and function of lipoproteins.
Review age-related changes within the circulatory system.
Describe the role of cholesterol in the development of atherosclerosis.
Describe the aetiology, pathophysiology, and clinical manifestations of atherosclerosis.
Describe the role of atherosclerosis in acute coronary syndromes, stroke, and peripheral vascular disease.
Fats are not water-soluble; they need to be wrapped in protein for transport through the blood.
Types of cholesterol: "bad" (LDL) and "good" (HDL) lipoproteins.
Cholesterol and triglycerides are transported in plasma by apoproteins.
LDLs are "bad cholesterol" and are removed from the blood by receptors in the liver, tissues, and macrophages.
HDLs are "good cholesterol" and transport cholesterol from tissues to the liver for excretion or reuse.
Differing opinions and research on whether sugar is the main dietary factor in cholesterol and atherosclerosis.
Excess glucose can be converted into fatty acids.
Abnormal thickening and hardening of artery walls.
Smooth muscle cells and collagen fibers enter the tunica intima, making it stiff and narrowing the lumen.
A specific form of arteriosclerosis with soft deposits of intra-arterial fat and fibrin in the vessel walls.
Main cause of coronary heart disease and cerebrovascular disease.
Endothelium cell injury is a risk factor.
Inflammatory cells adhere to the injured endothelium, causing more damage to the vessel wall.
LDL is oxidized by toxic oxygen radicals and engulfed by macrophages, forming foam cells.
Foam cells increase in number and form fatty streaks.
Fatty streaks produce more toxic oxygen radicals, further damaging the vessel wall.
Macrophages release growth factors that stimulate smooth muscle cell proliferation.
Smooth muscle cells and collagen migrate over the fatty streak, forming a fibrous plaque.
Fibrous plaque may calcify, protrude into the vessel lumen, and obstruct blood flow.
Fibrous plaque may rupture, leading to platelet adhesion, clotting cascade, and thrombus formation.
Atherosclerosis is responsible for about 33% of deaths in New Zealand.
Associated with high obesity rates, lack of exercise, and unhealthy diets.
Coronary artery disease: plaque buildup in an artery, leading to angina or heart attack.
Stable or classic angina is common and comes on with increased myocardial oxygen demands.
Sub-sternal constricting pain associated with a stable plaque.
Silent ischemia may have no angina pain but may have dyspnea and fatigue.
Chronic progressive disease with partial or total arterial occlusion in the lower extremities.
Affects older age group and younger persons with diabetes.
75-80% of all strokes are ischemic, caused by occlusion of cerebral artery from atherosclerosis.
May be preceded by TIA (transient ischemic attack), a short period of cerebral ischemia that resolves without infarction.
Reducing cholesterol
Increase exercise and physical activity
Smoking cessation
Eat a wide variety of plant-based foods