CVD: Risk factors & Cardiac Biomarkers Flashcards
Cardiovascular disease
• Angina – lack of oxygen to heart (ischaemia)
• MI- Myocardial infarction , ‘heart attack’
– coronary thrombosis
– death of heart muscle
• Heart failure – LVF, RVF congestive
• Hypertension
• Cerebrovascular disease (stroke) ischaemic haemorraghic
Risk factors for CVD
Two thirds of coronary deaths occur outside hospital
Half within one hour of onset of final illness
Highlights importance of preventative measures
Involves inherent/genetic - environmental factors
“Multi –factorial”
Identification of: key risk factors at risk individuals/population groups
Aim
Prevention – by early intervention
Screening – for risk factors
Importance of public education- awareness –public health
CVD- underlying causes
• Arteriosclerosis – cholesterol, blood lipids,
– genetics
– lifestyle
– age, gender
• Thrombosis/ thrombogenesis
– Genetics – clotting factor mutations eg. factor V Leiden
– smoking
• Hypertension
• Metabolic syndrome
• Diabetes, especially type 2 diabetes mellitus
• Inflammation
Risk factors for CVD/CHD
- Family history
- Gender
- Age
- Blood lipids
- Hypertension
- Cigarette smoking
- Obesity
- Lifestyle - stress/personality/exercise
- Diet
- Others – eg. environmental exposure
CVD- assessing the risks for health
promotion interventions and risk reduction
• Gender, age
• family history, premature coronary artery disease
• Hyperlipidemias/dyslipidemia - blood lipids,
lipoproteins
• Primary hyperlipidemia
– Inherited- familial – e.g. familial hypercholesterolaemia, FH
• Secondary hyperlipidemia
– environmental factors- diet, exercise, alcohol
– DM2, hypothyroidism,
• Metabolic syndrome, DM2
– Hypertension
– Abdominal fat, W/H ratio
– Dyslipidemia
Blood cholesterol & Lipoproteins
Lipoproteins
Protein-triglycerides-cholesterol particles
Transport cholesterol and TG around blood
Different ones:
VLDL, IDL, LDL, LDL- lipoprotein a Elevated levels- increased risk
HDL- Elevated levels- decreased risk
Lipoproteins are made in the body -
NOT eaten !
Lipoproteins versus cholesterol
- HDL:LDL cholesterol ratio more important
- IDL important risk factor- increased in metabolic syndrome
- Optimal Levels:
Total cholesterol < 4 mmol/L
LDL cholesterol < 2.5 mmol/L
HDL cholesterol > 1 mmol/L
TC:HDL ratio < 4.5
Triglycerides < 1.7 mmol/L
Factors affecting lipoproteins levels
- Diet- fat , type of fat
- Dietary fibre
- Protective components- folate, anti oxidants, phytosterols
- Alcohol – limit
- Sugar, salt – reduce intake
- DASH diet, Mediterranean diet
Lowering cholesterol
Dietary intervention - not a low cholesterol diet but a blood cholesterol-lowering diet!
Cholesterol- is produced in the liver – main
source- not diet!
Only 25% of blood cholesterol comes from diet – 75%
made in liver!
Needed to make steroid hormones, vit D, cell membranes
Cholesterol lowering diets
• Specific diets - Mediterranean diet, DASH (Dietary Approaches to Stop Hypertension) diet
• Key common features- More wholegrains, fruit and veges
Less energy dense high fat or highly refined, high GI carbohydrate foods
Low fat dairy, lean flesh, legumes
Olive oil (monounsaturated), fish, omega-3-fatty acids
• Part of a lifestyle !! – not a ‘diet’
Obesity- BMI or W/H ratio?
• CVD risk is intimately linked with obesity
• BMI ranges- <25(26), 25(26)-30(32), >30(32)
influence of ethnicity
More recently…..
• Fat distribution – ‘apples’ ^ risk compared to ‘pears’
• Metabolic syndrome – syndrome X- waist, waist/hip ratio
• Yo-yo dieting– increases risk
• Weight loss versus sustained healthy eating + exercise
Prenatal influences
- Barker hypothesis - epidemiological studies
- Animal models - human studies
- Intrauterine growth restriction - exhibit catch up growth after birth
- In adult life- ‘apple’ type obesity, hypertension, dyslipidemia and, increased risk for DM2 and cardiovascular disease
- Aggravated with high fat diet during post-natal life
- Converse also – excessively large babies
- Epi-genetics- influences regulation of gene expression
- Adaptive response – environment - early development
- maladaptive responsive if environment changes
- Thrifty genotype
Inflammation
Oxidised LDL
CVD risk – clinical & laboratory tests
• Age, gender, life style- smoking, diet, physical activity, stress etc
• Family history - ? Genetic testing?
• Weight- BMI –but more important - %body fat, distribution, W/H ratio
• Blood pressure
• Lipoproteins ‘blood lipids’
– Ideal fasting plasma cholesterol ,5.2mmol/L > 6.5mmol/L doubles the risk
– Total cholesterol/HDL-cholesterol ratio = or < 4.97 (men) 4.4 (women)
• Metabolic risk factors- impaired fasting blood glucose and other markers of the metabolic syndrome, DM2
• Lp(a) protein - increased levels increased risk
• CT scan for calcium levels in coronary artery
• C-reactive protein- elevated levels impendent risk - inflammatory
marker, non –specific
• Homocysteine levels –elevated levels increased risk – originsgenetic, link with folic acid, B12, B6 deficiency
• Elevated plasma fibrinogen - thrombogenesis
Laboratory tests to diagnose MIcardiac
enzymes/biomarkers
Established: Tropinin T (or Tn I) Creatine Kinase - CKMB Myoglobin Total CK aspartate aminotransferase (AST) Urea-stable Lactate Dehydrogenase (LD or LDH)
Experimental:
eg. ST2, BNPsp
