Cardiovascular Risk Factors 1 + 2 Flashcards
Most common cause of premature (<75 yr) death?
Coronary heart disease (CHD)
Atherosclerosis?
Progressive disease characterized by buildup of plaque within the arteries
Composition of plaque?
Fatty substances, cholesterol, cellular waste, calcium, and fibrin
What 2 things can lead to blockage of artery with regards to atherosclerosis? What can this result in?
- bleeding into the plaque
- formation of clot on surface of the plaque
- heart attack or stroke
At what stage does angina develop from atherosclerosis? At what stage does MI, stroke and leg ischaemia develop from atehroscleorosis?
- Development of fibrous and atherosclerotic plaque
* Plaque rupture/fissure and thrombosis
What is atherothrombosis? How does this process occur?
- Formation of an acute thrombus in a vessel affected by atherosclerosis
- Atherosclerotic plaque becomes unstable and ruptures, exposing components like collagen and von Willebrand factor allowing platelets to adhere to damaged area and form thrombus
Risk factors for cardiovascular disease? (11)
- Family history and ethnicity
- High BP
- Diabetes
- Heart disease
- Smoking
- Obesity
- Oral contraception and HRT
- Previous strokes and TIAs
- Excessive alcohol consumption
- Inactivity
- Age
What are modifiable risk factors for CVD? (9) Non-modifiable? (4)
Modifiable
- Smoking
- Dyslipidaemia
- Raised BP
- Diabetes mellitus
- Obesity
- Diet
- Thrombogenic factors
- Lack of exercise
- Excess alcohol consumption
Non-modifiable * Personal history of CHD * Family history of CHD * Age * Gender
Relationship between BP and CVD?
Greater the blood pressure the greater the risk
What lipoproteins are implicated in atherosclerosis development? (3)
- LDL (most atherogenic)
- IDL
- VLDL
(not chylomicrons or HDL)
Relationship between LDL and CVD risk? What factors is LDL modified by? (4)
10% increase in LDL results in 20% increase
in CHD risk
- low HDL cholesterol
- smoking
- hypertension
- diabetes
What is absolute risk of disease? Relative risk?
- Absolute risk - risk of developing the disease over a time period
- Relative risk- comparison of risk in two different groups of people
Are triglycerides as atherogenic as LDL? Normal triglyceride levels? High triglyceride levels?
- No, associated with increased risk CHD but not as much as LDL
- Normal - 2.3mmol/l
- High - 11.3mmol/l
What does hypertriglyceridaemia due to chylomicrons and large forms of VLDL result in?
Pancreatitis but not CHD as chylomicrons and VLDL too large to enter arterial wall
When will HDL cholesterol increase risk of CHD? What lowers HDL cholesterol? (4)
When low level (<1 mmol/l)
- High levels of triglyceride
- Smoking
- Obesity
- Physical inactivity
What transports triglyceride from gut to the liver? From liver to the rest of the body?
- Chylomicrons
* VLDL (most transformed into LDL via IDL and bound to LDL receptor)
What is the exogenous pathway of lipid metabolism?
Transport and utilisation of dietary fats via chylomicrons
Is cholesterol a modifiable risk factor?What are the benefits of reducing cholesterol?
Total cholesterol is a modifiable risk factor
10% reduction in total cholesterol results in
- 15% reduction in CHD mortality
- 11% reduction in total mortality
What is the primary target to lower cholesterol and thus CVD risk?
LDL-C
What is the relationship between serum total cholesterol and death rate from CHD?
Increased serum total cholesterol, increased death rate from CHD
(however, difference in mortality between different countries at given serum total cholesterol suggests other factors like diet also play a role)
What is primary prevention in CHD? Secondary prevention?
- Crucial opportunity to reduce the burden of CHD
* Following MI, etc, to prevent it from happening again
Relationship between 10% reduction in total cholesterol and age?
Risk of coronary heart disease lowers less as we age - decrease in absolute risk, but increase in relative risk?
(i.e. falls by 50% at age 40 but only 20% at age 70)
What is the main effect of statins? Other actions? (5)
- Reduction of total cholesterol and LDL cholesterol
- improvement of endothelial dysfunction
- increased nitric oxide bioavailability
- antioxidant properties
- inhibition of inflammatory responses
- stabilisation of atherosclerotic plaques
Mechanism of statins?
HMG-CoA reductase inhibitors
What are physical manifestations of high cholesterol?
- Xanthelasma
- Tendon Xanthomas
- Tuberous xanthomas
- Eruptive xanthomas
What are xanthelasmas, tendon xanthomas, tuberous xanthomas and eruptive xanthomas? What are they indicative of?
- Xanthomas of the eyelids (hyperlipidaemia)
- Xanthomas on extensor tendons of fingers, patella, elbows, Achilles tendon (hypercholesterolaemia)
- Xanthomas in dermis and subcutaneous tissue of extensor surfaces of large joints, hands, buttocks, heels, flexures (familial or acquired hypertriglyceridaemias and biliary cirrhosis)
- Small reddish-yellow papules on buttocks, posterior thighs, body folds (abrupt increase in serum triglyceride levels)
Some diseases attributable to hypertension? (6)
- Heart failure
- MI
- Cerebral haemorrhage
- Stroke
- Left ventricular hypertrophy
- Coronary heart disease
Types of hypertension?
- Primary (essential) hypertension - 90% of cases (majority), no known cause
- Secondary - underlying cause
What increases prevalence of hypertension?
Increasing age
What are the effects of hypertension treatment?
Reduces
- Ischaemic Heart Disease
- Stroke
- Mortality
What are lifestyle modifications to reduce hypertension?
- Lose weight, if overweight
- Limit alcohol intake
- Increase physical activity
- Reduce salt intake
- Stop smoking
- Limit intake of foods rich in fats and cholesterol
Why is hypertension a complicated risk factor of CVD? Examples? (6)
Most hypertensives have other CV risk factors
- Dyslipidaemia
- Diabetes
- Age
- Male
- Smoking
- Family history
What is the first line treatment for young patents with hypertension? Older?
- Young - start with ACE-I or ARBS
* Older - start with Ca++ channel blocker
What is the most effective way to treat hypertension?
Combination therapies (different types of drug used rather than using increased dose of one drug)
Why is diabetes one of the main risk factors for atherosclerosis? (3)
- Increases hypercoaguability of blood (Virchow’s triad)
- Increased LDL levels and decreased HDL
- Increased endothelial damage due to oxidative stress
What is the ticking clock hypothesis for diabetes?
Must be diagnosed quickly
- Microvascular changes occur at onset of hyperglycaemia
- Macrovascular changes occur before diagnosis of hyperglycaemia
What is the probability of death in patients with diabetes with prior MI?
50% survival after 8 years
What is the main cornerstone of obesity treatment?
Diet
- Micronutrients, antioxidants, omega 3 and 6, polyunsaturates and monounsaturates
- Calorie intake to normalise weight
- Plus or minus exercise program
What conditions are people with obesity at risk of? (5)
- Stroke
- Angina
- MI
- Hypetension
- Type 2 diabetes
What are the characteristics of metabolic syndrome?
To achieve diagnosis, must have 3or ore of these characteristics
- Abdominal obesity (waist circumference >40 in males and >35 in females)
- Triglycerides (>1.7mmol/l)
- HDL-C (<1 mmol/l in men and 1.3 mmol/l in women)
- Blood pressure (130/85 mm Hg)
- Fasting glucose (>5.6 mmol/l)
Can inflammatory markers predict future coronary events?
Some debate over whether high sensitivity CRP test can e reflective of increased CVD risk (increased levels of CRP indicate inflammation)
What are socio-economic differences in CVD?
Premature deaths from CHD greater for manual workers than non manual (58% higher)
Relationship between ischaemic heart disease and deprivation?
IHD mortality increases as deprivation increases
What are ethnic differences in CVD? (2)
- South Asians living in the UK have a higher death rate for CHD
- Black Caribbean & black Africans much lower CHD death rate than average
- BUT much higher risk in stroke
What is ASSIGN score used for?
Estimate the risk of CVD
What are levels of risk associated with smoking, hypertension and hypercholesterolaemia?
- Risk multiplies as a combination of these factors (16 fold increase in risk)
What are treatments for ischaemia in CVD? (2) Examples?
- Anti-anginal medications (calcium blockers, nitrates, beta blockers)
- Revascularisation (angioplasty, CABG)
What are the treatments for antherothrombosis in CVD?
- Aspirin
- Statin
- Beta Blocker
- ACE Inhibitor
- Exercise
- Smoking Cessation