Cardiovascular Disease Flashcards
Define cardiovascular disease.
- give examples of CVD’s
- prevalence
- aetiology
General term for conditions affecting the heart or blood vessels.
EXAMPLES OF CVD’S:
- coronary heart disease: affects blood vessels in the heart & circulatory system
- cerebrovascular disease: affects blood vessels supplying the brain
- myocardial infarction
- stroke
- congenital heart disease
PREVALENCE:
- leading cause of death in UK
AETIOLOGY:
- multifactorial
- modifiable risk factors: smoking, diet, family history, PAL & dyslipidaemia
- can be caused by atherosclerosis (chronic) or thrombosis (acute).
What are the most important risk factors for CVD?
- Hyperlipidaemia
- Hypertension
- Cigarette smoking
- Diabetes/insulin resistance
- Obesity (particularly central obesity)
- Lack of physical activity
- Diet
Describe the relationship between blood lipids and CVD risk.
- dyslipidaemia definition
- HDL vs LDL cholesterol
- causes of hyperlipidaemia
- lipid profile targets
Lipids transport through blood via lipoproteins:
- HDL: cardioprotective, protects by transporting cholesterol to the liver for excretion.
- LDL: higher risk of atherosclerosis & CVD as promotes atherosclerosis by transporting cholesterol into arterial wall.
Hyperlipidaemia is associated with increased atherosclerosis/CVD risk:
- elevated LDL
- decreased HDL
- elevated TG
Hyperlipidaemia can have primary (genetic) and secondary (lifestyle) causes.
LIPID PROFILE TARGETS:
Total cholesterol: < 5mmol/L
LDL: < 4mmol/L
HDL: > 1mmol/L (M), > 1.2 mmol/L (F)
Triglycerides: < 1.7mmol/l
Describe the relationship between hypertension and CVD risk.
- definition
- cause
- cardiac, vascular and renal effects
DEFINITION:
- When the force of blood flowing through your blood vessels, is consistently too high, caused by excessive vasoconstrictrion of blood vessels
- Normal BP: < 120/80
- High BP: 140/90
CAUSE:
- primary: unknown
- secondary: lifestyle
EFFECTS:
- cardiac: increased workload for heart –> heart enlarges –> heart failure
- vascular: increased pressure –> damage –> inflammation –> atherosclerosis –> rupture
- renal: injury to delicate kidney –> renal failure.
What is the relationship between apolipoproteins and CVD risk?
Apolipoproteins show independent associations with CVD risk after adjustment for conventional lipids (LDL, HDL, vLDL etc.)
There are 8 classes of apolipoprotein.
- Triglyceride-carrying apolipoproteins (ApoC1, ApoC3, and ApoE) were most strongly associated with the risk of CHD
- The Apo B:Apo A1 ratio was shown to be superior to HDL:LDL ratio for estimating risk of acute MI.
- high serum levels of both Apo B and Apo A1 also linked to the development of atherosclerosis
- low levels Apo C3 are associated with cardiovascular protection.
Describe the nutritional management of CVD.
NICE GUIDELINES:
1st line treatment: adherence to cardioprotective diet.
Cardioprotective diet is constructed around mediterranean diet.
- Not specific diet, more of a change in overall eating pattern.
Main focus fat intake:
total fat < 30% calories
sat fat < 7% intake (ideally replace with unsaturated fats).
- can be used in conjunction with more specific dietary advice e.g., diabetes, renal, HTN (DASH)
What are the principles of the cardioprotective diet?
- reduce sat fat (< 7%)
- increase intake of MUFA & PUFA
- increase wholegrains
- reduce simple/refined sugar intake
- minimum 5 x fruit & veg per day
- fish twice a week (1 x oily)
- increase intake nuts (unsalted), pulses, legumes
- do not exceed 14 units alcohol/week and spread out over the week.
- < 6g salt/day
Discuss the efficacy of the cardioprotective diet.
- how does it work to prevent CVD?
Inverse association between greater Mediterranean dietary adherence versus CVD incidence and mortality.
The cardioprotective diet affects CVD by altering a wide range of risk factors in a positive way, including:
- reduces BP
- reducing inflammation
- reducing lipid oxidation
- decreases lipid plaque formation (improved blood lipid profile, decreases homocysteine levels)
- decreases chance of thrombosis (decreases platelet aggregation, clotting factors)
what are the total fat and sat fat recommendations in uk?
- what are the current avg intakes?
total fat: < 35% calories
current intake:
- men and women achieve this
sat fat: <10% calories
current intake:
men: 12.3%
women: 12.7%
How does dietary fat affect CVD risk?
- what are the recommendations for fat intake?
- why is oily fish recommended in the cardioprotective diet?
saturated fat and trans saturated fat contributes to CVD risk.
trans fatty acids shown to raise LDL cholesterol whilst lowering HDL.
omega-3 fatty acids are cardioprotective by improving endothelial function and have anti-inflammatory and antithrombotic effects.
recommendations:
- replace sat and trans sat fats with MUFA & PUFA
- oily fish once per week
- vege sources of omega 3 include nuts, seeds, rapeseed oil, soya products.
*oily fish:
Fish oils and PUFA’s
- Reduced platelet aggregation
- Positive effect on cardiac electro-physiology, endothelial function, blood pressure, vascular reactivity and inflammation
Omega 6
- reduces LDL & platelet aggregation
what is the relationship between salt and CVD risk?
what are the recommendations for salt intake in UK?
Salt intake contributes to HTN.
recommended <6g salt (2.4g sodium) per day
DASH diet (dietary approaches to stop hypertension)
- largely the same as cardioprotective diet
- <2g salt/day
HOWEVER:
systematic review found no significant effect of reducing salt intake on CVD events in hypertensive and normotensive people.
Could there be an adverse effect of reducing salt on heart function?
Describe the Framington Heart Study
Established 1948
The longest running cohort study discovering common factors for CVD
- 2748 participants aged 50-79
Low levels HDL-C increased mortality (stronger in men than women)
Describe the 7 countries study
First major study to investigate diet and lifestyle along with other risk factors for CVD, across contrasting countries and cultures and over an extended period of time.
- Men 40-59 years
- USA, netherlands, finland, italy, greece, yugoslavia, japan
FINDINGS;
- % calories from saturated fat increases –> serum cholesterol increases
- Saturated fat intake increases –> CHD incidence increases
- Increased serum cholesterol –> increased CHD death.
Describe the role of exercise in CVD risk
UK recommendations for exercise:
- 150 mins moderate intensity exercise/week
- include both aerobic and resistance training.
Exercise needs to be aerobic to have antihypertensive effect however does not have to be high intensity e.g., walking
- yoga shown to increase odds of maintaining normal BP
