Please can you explain how to do the following:
a) a non-smoker with low blood pressure has a plasma chloesterol concentration of 5mmol per litre. Over a period of time this concentration increases to 8mmol per litre. By how many times has this risk of heart disease increased? Show your working.
b) Two non-smoking men with low blood pressure both have plasma chloesterol concentrations of 5mmol per litre. One of them starts to smoke and the plasma chloesterol concentration of the other increases to 7mmol per litre. Which man is now at the greater risk of heart disease? Explain your answer.
Many thanks
a) To calculate how many times the risk of heart disease has increased, we need to compare the initial cholesterol concentration (5mmol/L) to the final cholesterol concentration (8mmol/L).
The first step is to calculate the increase in cholesterol concentration, which is found by subtracting the initial concentration from the final concentration:
Increase = Final concentration - Initial concentration
Increase = 8mmol/L - 5mmol/L
Increase = 3mmol/L
Next, we divide the increase in cholesterol concentration by the initial concentration to determine the increase as a multiple:
Increase as multiple = Increase / Initial concentration
Increase as multiple = 3mmol/L / 5mmol/L
Increase as multiple = 0.6
Therefore, the risk of heart disease has increased by 0.6 times or 60%.
b) To determine which man is at a greater risk of heart disease, we need to compare their final cholesterol concentrations.
The first man starts with a cholesterol concentration of 5mmol/L and does not smoke, so his cholesterol concentration remains the same.
The second man's cholesterol concentration increases to 7mmol/L due to smoking.
Comparing the two concentrations, we can see that the man with a cholesterol concentration of 7mmol/L is at a greater risk of heart disease.
The reason for this is because increased cholesterol levels are associated with an increased risk of heart disease. So, the man with a higher cholesterol concentration (7mmol/L) is at a greater risk compared to the man with a lower concentration (5mmol/L). Therefore, the second man who started smoking is at a greater risk of heart disease.