Atherosclerosis

Question 1

Pathophys of atherosclerosis

Answer 1

1) increased enthelial permeability
2) LDL enters intima due to increased serum LDL
3) LDL becomes trapped and undergo oxidative modification
4) mLDL induces cytokine elaboration –> increase expression of adhesion molecules that bind leukocyte and chemoattractant molecules
5) Blood monocytes uptake mLDL via scavenger receptors and develop into foam cells
6) Macrophage foam cells also produce cytokines that cause smooth muscle cells to migrate from media into the intima
7) Smooth muscle cells promote matrix accumulation and atherosclerotic plaque formation
8) later stages: calcification can occur

Question 2

Fatty streak

Answer 2

earliest visible lesion of atherosclerosis
yellow discolouration on artery’s inner surface
do not protrude into lumen/impede blood flow
exists in most people by 20
only reversible phase of atherosclerosis
caused by early infiltration of lipids into subintima

Question 3

Complicated atherosclerotic lesion

Answer 3

fibrous plaque becomes involved with thrombus, hemorrhage and/or calcification

Question 4

Xanthoma

Answer 4

plaques or nodules consisting of abnormal lipid deposition and foam cells
Macrophages uptake lipid (with scavenger receptors) that has been transported through capillary walls –> foam cells
LDL can also recruit additional foam cells
Local factors (heat, movement, friction) may increase LDL capillary leakage –> localization

Question 5

Classification of xanthomas

Answer 5

Eruptive: reddish-yellow papules on extensor surface of extremities/buttocks
Tuberous: nodules: extensor surface of elbow, knee, knuckle, buttocks
Tendinous: firm s/c nodules on tendons - Achilles, extensor tendons of hands/knees/elbow
Planar: yellow macules, soft papules, or plaques on upper eyelids (xanthelasma), palms (xanthoma striatum palmare), and intertriginous areas

Question 6

Xanthelasma

Answer 6

xanthomas in the upper eyelid

Question 7

Therapeutic lifestyle change

Answer 7

increased physical activity
weight reduction
reduced dietary intake of saturated fat and cholesterol
Increase soluble fiber - 10-25g/day
Cholesterol lowering foods: margarines, salad dressings, other oil-based items that contain plant sterol esters/plant stanol esters - 2g / day

Question 8

Metabolic syndrome criteria

Answer 8

>=3 of: 
waist circumference >102 men, >88 women
serum triglyceride > 1.7
HDL  130/85
glucose >6.1