11a. CV Health - General Flashcards
What is CVD?
General term for conditions affecting the heart and blood vessels
What is the endothelium?
Single layer of endothelial cells lining the blood interface throughout the CVS
What is the glycocalyx?
Carb-rich protective layer covering the ED
Regulates permeability
Controls NO production
Mechanosensor of blood shear stress
What can damage the glycocalyx?
Inflammation
Hyperglycaemia
Endotoxaemia
Oxidised low density proteins
Abnormal blood sheer stress
What can further damage to the glycocalyx do?
Further damage to the endothelium
Promotes lipid deposition
Atherosclerosis
What are the functions of the endothelium (ASHIER)?
Angiogenesis
Semi-permeable barrier
Haemostasis
Immune defence
Enzymes
Regulates vascular tone
What is the function of the endothelium in angiogenesis?
Endothelium cells are the origin of all new blood vessels
What is the function of the endothelium as a semi-permeable barrier?
Fluid balance
Host defence
Selective movement of substances e.g. glucose, O2
What is the function of the endothelium in haemostasis?
Luminal surface of endothelium prevents platelet adherence and coagulation
What is the function of the endothelium in immune defence?
Healthy endothelium cells deflect leukocyte adhesion and oppose local inflammation
What is the function of the endothelium in enzymes?
Endothelium contains angiotensin converting enzyme (ACE)
Plays a key role in regulating blood pressure
What is the function of the endothelium in regulating vascular tone?
Secretes vasodilators (e.g. NO) and vasoconstrictors (e.g. endothelin)
What are vascular smooth muscle cells (VSMCs)?
Play a key role in vessel contraction and dilation
(regulate blood circulation and pressure)
Maintain the integrity and elasticity of blood vessels
Limits immune cell filtration
Where are VSMCs located?
Tunica media
What happens to VSMCs under pathological conditions?
They undergo phenotypic modulation where the cell structure and function is altered
(central to atherosclerosis/hypertension)
What is the role of NO in CV health (RRRIO)?
Regulates vascular tone
Reduces platelet aggregation
Reduces VSMC proliferation
Inhibits leukocyte adhesion and inflammatory cytokines
Opposes oxidation from LDLs
Which amino acid generates NO?
L-arginine
Which enzyme generates NO from L-arginine?
eNOS
Which vitamin regulates NO synthesis by mediating eNOS?
D
How does NO exert its physiological effects?
Diffuses from endothelium into VSMCs and bloodstream of large vessels
What does reduced NO contribute to?
Atheroma formation
CVD
How do normal endothelial cells work?
Impermeable to large molecules
Anti-inflammatory
Deflects leukocyte adhesion
Enhance vasodilation
Resist thrombosis
How do endothelial cells impacted by OS and inflammation work?
Increased permeability
Inflammatory cytokine and leukocyte adhesion
Reduced vasodilator molecules
Increased risk of thrombosis
How do normal VSMCs work?
Normal contractile function maintaining extracellular matrix
Contained within the tunica media
How do VSMCs impacted by OS and inflammation work?
Increased inflammatory cytokines and extracellular matrix synthesis
Migration into the tunica intima
Proliferation of VSMCs
What are peroxisome proliferator-activated receptors (PPARs)?
Nuclear transcription factors that control gene expression involved in adipogenesis, lipid and glucose metabolism and cellular proliferation/apoptosis
Decrease inflammation and promote endothelium health
What physiological changes occur when PPAR-a is activated?
Increased HDL-C
Reduced triglycerides
Reduced inflammation
Anti-atherosclerotic
Which nutrients/herbs work with PPAR-a?
Green tea
Resveratrol
Oregano
Thyme
Rosemary
Naringenin
O3
What is the role of PPAR-y?
Reduced blood glucose
Reduced fatty acids
Reduced insulin
Which nutrients/herbs work with PPAR-y?
Hesperidin
EGCG
Resveratrol
Curcumin
Examples of CV markers on tests
Cardiac risk tools
Cardiac troponin
Lipid profile
Lp-PLA2
hsCRP
MPO
What are cardiac risk tools?
e.g. QRISK
Calculate score based on CV risks - age, BMI, smoking
What are cardiac troponin markers on a test?
Cardiac troponin proteins hs-cTnT and hs-cTnI are released into blood when heart muscle is damaged
Often used alongside ECG
What are lipid profiles on a test?
TC
Non-HDL
TG
LDL-C
TC:HDL ratio
What are the normal levels for lipid profiles on a test?
TC - <5 mmol/L
Non-HDL - <4 mmol/L
LDL-C - <3 mmol/L
HDL - >1 mmol/L (m); >1.2 mmol/L (f)
What lipid levels on a test pose a higher risk for CVD?
TG - >2.3 mmol/L
TC:HDL ratio - >6 mmol/L
What is Lp-PLA2?
Enzyme produced by monocytes, macrophages, T cells
Upregulated in atherosclerotic plaques and vascular inflammation
What is hsCRP?
Inhibits NO and eNOS
Involved in plaque deposition
What is low risk hsCRP on a test?
<1.0 mg/L
What is high risk hsCRP on a test?
> 3.0 mg/L
What diet and lifestyle factors elevate both Lp-PLA2 and hsCRP?
Western diet
Sedentary lifestyle
Periodontal disease
What is MPO on a cardiac test?
Released by macrophages
Measures body’s response to damaged arterial walls
What is high MPO associated with?
Inflammation
OS
Poor prognosis
What are MPO levels exacerbated by?
High BP
Obesity
Smoking
What is LDL-P on a cardiac marker test?
Number of particles
Correlates with atherosclerosis
Closely associated with obesity, diabetes and IR
