What are cardiovascular diseases?

Cardiovascular diseases are diseases of the heart (cardiac muscle) or blood vessels (vasculature). However, in practice, when doctors use the term 'cardiovascular disease' they usually mean diseases of the heart or blood vessels that are caused by atheroma. Patches of atheroma are like small fatty lumps that develop within the inside lining of arteries (blood vessels). Atheroma is also known as 'atherosclerosis' and 'hardening of the arteries'.

Cardiovascular disease that can be caused by atheroma include: angina, heart attack, stroke, transient ischaemic attack (TIA), and peripheral vascular disease. In the UK, cardiovascular diseases are a major cause of poor health and the biggest cause of death.

Risk factors

Everybody has some risk of developing atheroma which may cause one or more cardiovascular diseases. However, certain 'risk factors' increase the risk. Risk factors include:

• Lifestyle risk factors that can be prevented or changed:
  • Smoking.
  • Lack of physical activity (a sedentary lifestyle).
  • Obesity.
  • An unhealthy diet.
  • Excess alcohol.
• Treatable or partly treatable risk factors:
  • Hypertension (high blood pressure).
  • High cholesterol blood level.
  • High trigliceride (fat) blood level.
  • Diabetes.
  • Kidney diseases that affect kidney function.
• Fixed risk factors - ones that you cannot alter:
  • A strong family history. This means if you have a father or brother who developed heart disease or a stroke before they were 55, or in a mother or sister before they were 65.
  • Being male.
  • An early menopause in women.
  • Age. The older you become, the more likely you are to develop atheroma.
  • Ethnic group. For example, people who live in the UK with ancestry from India, Pakistan, Bangladesh, or Sri Lanka have an increased risk.
  However, if you have a fixed risk factor, you may want to make extra effort to tackle any lifestyle risk factors that can be changed.

Note: Some risk factors are more 'risky' than others. For example, smoking and high blood pressure cause a greater risk to health than obesity. Also, risk factors interact. So, if you have two or more risk factors, your health risk is much more increased than if you just have one. For example, a middle aged male smoker who takes no exercise and has high blood pressure has a high risk of developing a cardiovascular disease such as a heart attack before the age of 60.

Therefore, the benefit of lowering a high blood pressure is to reduce the risk of developing a cardiovascular disease in the future.

For example, it is estimated that reducing a high diastolic blood pressure by 6 mmHg reduces your relative risk of having a stroke in the future by about 35-40%, and reduces your relative risk of developing heart disease by about 20-25%. Larger reductions in blood pressure provide greater benefits. (See leaflet called 'Absolute Versus Relative Risk' for an explanation of relative risk. For a full discussion on exactly how much risk is reduced by lowering blood pressure, see the Hypertenion Guidance at Prodigy - www.prodigy.nhs.uk)

Assessing (calculating) your cardiovascular health risk

A 'risk factor calculator' is often used by doctors and nurses to predict the health risk for an individual. A score is calculated which takes into account all your risk factors (such as age, sex, smoking status, blood pressure, blood cholesterol level, etc). If you want to know your 'score', see your practice nurse or GP. Current UK guidelines advise that if your score gives you a 2 in 10 risk (or more) of developing a cardiovascular disease within the next 10 years, then treatment is advised. Treatments may include:

• A drug to lower blood pressure if it is 140/90 mmHg or higher.
• A drug to lower your cholesterol level.
• A daily low dose of aspirin. This reduces the risk of blood clots forming in the blood vessels over patches of atheroma (which cause strokes and heart attacks).
• where relevant, to encourage you to tackle 'lifestyle' risk factors such as smoking, lack of physical activity, diet, and weight.

How can blood pressure be lowered?

There are two ways in which blood pressure can be lowered.

• Modifications to lifestyle (weight, exercise, diet, salt, and alcohol) if any of these can be improved upon (details below).
• Medication (details below).

Lifestyle treatments to lower high blood pressure

Lose weight if you are overweight
Losing some excess weight can make a big difference. Blood pressure can fall by up to 2.5/1.5 mmHg for each excess kilogram which is lost. Losing excess weight has other health benefits too.

Regular physical activity
If possible, aim to do some physical activity on five or more days of the week, for at least 30 minutes. For example, brisk walking, swimming, cycling, dancing, etc. Regular physical activity can lower blood pressure in addition to giving other health benefits. If you previously did little physical activity, and change to doing regular physical activity five times a week, it can reduce systolic blood pressure by 2-10 mmHg.

Have a low salt intake
The amount of salt that we eat can have an effect on our blood pressure. Government guidelines recommend that we should have no more than 5-6 grams of salt per day. (Most people currently have more than this.) Tips on how to reduce salt include:

• Use herbs and spices to flavour food rather than salt.
• Limit the amount of salt used in cooking, and do not add salt to food at the table.
• Choose foods labelled 'no added salt', and avoid processed foods as much as possible.

Eat a healthy diet
Briefley, this means:

• AT LEAST five portions, and ideally 7-9 portions, of a variety of fruit and vegetables per day.
• THE BULK OF MOST MEALS should be starch-based foods (such as cereals, wholegrain bread, potatoes, rice, pasta), plus fruit and vegetables. 医学全在线网站www.med126.com
• NOT MUCH fatty food such as fatty meats, cheeses, full-cream milk, fried food, butter, etc. Use low fat, mono-, or poly-unsaturated spreads.
• INCLUDE 2-3 portions of fish per week. At least one of which should be 'oily' such as herring, mackerel, sardines, kippers, pilchards, salmon, or fresh (not tinned) tuna.
• If you eat meat it is best to eat lean meat, or poultry such as chicken.
• If you do fry, choose a vegetable oil such as sunflower, rapeseed or olive oil.
• Low in salt.

A healthy diet provides health benefits in different ways. For example, it can lower cholesterol, help control your weight, and has plenty of vitamins, fibre, and other nutrients which help to prevent certain diseases. Some aspects of a healthy diet also directly affect blood pressure. For example, if you have a poor diet and change to a diet which is low-fat, low-salt, and high in fruit and vegetables, it can lower systolic blood pressure by up to 11 mmHg.

Drink alcohol in moderation
A small amount of alcohol (1-2 units per day) may help to protect you from heart disease. One unit is in about half a pint of normal strength beer, or two thirds of a small glass of wine, or one small pub measure of spirits.

However, too much alcohol can be harmful.

• Men should drink no more than 21 units of alcohol per week (and no more than four units in any one day).
• Women should drink no more than 14 units of alcohol per week (and no more than three units in any one day).

Cutting back on heavy drinking improves health in various ways. It can also have a direct effect on blood pressure. For example, if you are drinking heavily, cutting back to the recommended limits can lower a high systolic blood pressure by up to 10 mmHg.

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