Risk Factors of CVD Flashcards
What is risk
The probability of occurrence of some unwanted event or outcome
Six reasons why people overestimate the risk of something happening
-involuntary
-unnatural
-unfamiliar
-dreaded
-unfair
-very small
What are risk factors
Things that increase the chance of the harmful outcome
When is there a correlation between two variables
When a change in one variable is accompanied by a change in the other
What is a positive correlation
When an increase in one variable is accompanied by an increase in the other
What is a negative correlation
When the value for one variable increases, the value for the other decreases
When are two variables causally linked
When a change in one variable is responsible for a change in the other
Null hypothesis
A hypothesis stating there will be no difference between an experimental and control group
What are cohort studies
Ones that follow a large group of people over time to see who develops the disease and who does not. Prospective as at the start of the study none of the pps have the disease. People’s exposure to suspected risk factors and whether they develop the disease is recorded meaning correlations can be drawn
What are case-control studies
A group of people with a disease are compared with a control group of individuals who do not have the disease, info collected about risk factors they have been exposed to in the past which means can identify factors which may have contributed to development of the disease
What do epidemiologists do
Study patterns in the occurrence of disease to look for correlations between a disease and specific risk factors
Features of a good study
-clearly stated hypothesis, which the design of the study must be appropriate to
-representative sample
-standardised procedure
-reliable and valid method of collecting data
-disease diagnosis must be clearly defined
-large sample=results could not have occurred by chance
-identify and manage control variables
Risk factors of CVD
-high blood pressure
-obesity
-dietary factors:salt, cholesterol
-smoking
-inactivity
-genetic inheritance
Why does risk increase with age
Arteries may become less elastic and more easily damaged
What is basal metabolic rate
Rate of the chemical reactions occurring in the body to support normal cell function
What happens to excess energy in the body
It is converted to glycogen or fat and stored in cells
What is BMI and how to calculate it
-classifies a person’s weight relative to their height
BMI=body mass(kg)/height2(m2)
Two limitations of BMI
-average for entire population so doesn’t take into account sex
-same volume of muscle has a greater mass than fat
What is waist-to-hip ratio
A better measure of obesity than BMI as shows a highly significant association with risk of heart attack if over 1
How does type two diabetes increase risk of CHD
As increase in blood sugar increases blood pressure and blood viscosity so higher chance of artery walls being damaged
How does smoking increase risk of CVD
-CO binds to haemoglobin which decreases oxygen supply to cells and increases heart rate
-nicotine stimulates adrenaline production which increases heart rate and causes arteries to constrict which increase bp
-chemicals found in smoke damage artery lining
Why does sickle cell anaemia increase risk of CVD
-haemoglobin less efficient at carrying oxygen due to sickle shape and can block small blood vessels increasing heart rate and bp
What is apolipoprotein A
-major protein in HDL which is involved in the removal of cholesterol from the blood into the liver
What is apolipoprotein B
-main protein in LDL which transfers cholesterol from the liver into cells
What is apolipoprotein E
-major component in HDL and very low-density lipoproteins
