Risk factors to the Cardiovascular System

Learning Outcomes Describe modifiable risk factors: diet, smoking, activity, obesity Describe non-modifiable risks: gender, age, heredity, race Describe the effect of exercise on heart rate, systolic and diastolic blood pressure, cardiac output and recovery time. Describe the distribution of blood to tissues during exercise.

Modifiable risk - DIET Healthy balanced diet, low in saturated fat and cholesterol. Alcohol intake – a small volume may be beneficial but too much => CVD/CHD. Fruit and Veg – contains vitamins A,C, E providing important antioxidants helping protect HDL. Fatty Acids (oily fish) – make blood less likely to clot. Fibre – reduces level of cholesterol absorbed from digested food.

Modifiable risk – SMOKING Nicotine – increases blood pressure by constricting blood vessels Carbon monoxide – binds to haemoglobin more effectively than oxygen so reducing the amount of oxygen carried by the blood. Both these substances increase heart rate Smoking can also damage lining of arteries, cause blood to clot and reduces HDL.

Modifiable risk - ACTIVITY People who do not exercise regularly are twice as likely to develop heart disease. Regular exercise – strengthens heart muscle, improves blood lipid profile, lowers blood pressure, helps weight loss by decreasing body fat.

Modifiable risk - OBESITY More energy is consumed than is used up – excess gets stored as body fat Lifestyle – high fat foods, low activity levels Higher risk of developing CVD including CHD, high blood pressure, stroke, angina, atherosclerosis.

Non-modifiable risk - AGE Men over 45 and women over 55 are at an increased risk of CVD. Risk of developing CVD increase with age – less elastic arteries,  blood pressure, atherosclerosis Natural effects of ageing can be minimised by controlling your weight, healthy diet, regular exercise.

Non-modifiable risk - GENDER Men are at greater risk from CVD than women. On average women develop coronary artery diseases 10yrs later then men.

Non-modifiable risk - Heredity If you have a family history of CVD you are at greater risk. Genetic link – high cholesterol levels, tendency to be obese, hypertension. Regular checks, medication and preventative steps will all reduce risk.

Non-modifiable risk – Race (Ethnicity) In Britain, mortality rates from CVD are around 40% higher amongst people with a South Asian background than those of the white population. This may be linked to increased rate of insulin resistance (and type 2 diabetes). Susceptible individuals should be monitored and take the recommended preventative steps.

Effect of Exercise.. on heart rate and recovery time During exercise the CVS must deliver more oxygen and nutrients and remove more waste products from muscles so heart rate increases. Recovery time is less in a fitter person.

…on blood pressure and cardiac output during exercise Systolic blood pressure usually increases but diastolic pressure remains fairly constant. Stroke volume and heart rate increases – ie. Cardiac output

…on redistribution of blood Exercising muscles have a greater requirement for oxygen, glucose and waste removal. Arterioles supplying exercising muscles dilate. Arterioles supplying tissues not involved in exercise constrict.

Typical Essay Question There are many risk factors which increase the likelihood of cardiovascular disease (CVD), some modifiable and some non- modifiable. Explain what is meant by the terms “modifiable” and “non-modifiable” and, using two named examples of each, explain their roles in CVD. (15 marks)

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