According to statistics from the World Heart Federation, cardiovascular disease - which includes heart diseases and stroke - is the world's leading cause of death. In Southeast Asia, it accounts for about 3.5 million deaths every year.
The good news is that heart disease is now mostly preventable and treatable, thanks to rapid advancements in medical science and progress with new diagnostic and treatment methods. Still, it is important to recognise the risk factors and estimate your susceptibility to coronary heart disease. By understanding and managing these factors, a patient can substantially lower his or her risk for heart disease.
What makes you at risk for coronary artery disease?
There are many risk factors for heart disease.
They are broadly classified into those that are modifiable (can be changed) and those that are non-modifiable (cannot be changed).
What are the non-modifiable risk factors?
These are risk factors that you have no control over. They are:
The older you are, the more susceptible you are to heart disease. For women, the effects of menopause - particularly the loss of natural oestrogen - appear to increase their risks of coronary heart disease and stroke.
Men are 3 to 5 times more likely to have coronary heart disease than women. However, the risk for women increases after menopause. By about 5 to 10 years following menopause, the risk for coronary heart disease for women increases to almost the same level as men.
Risk for coronary heart disease varies with different ethnic groups. A study done in Singapore shows that the likelihood for coronary heart disease is highest amongst South Asians, i.e. Indians, Pakistanis, Bangladeshis, etc. South Asians are 3 times, and Malays are 2 times more likely than Chinese to suffer from coronary heart disease.
Certain risk factors tend to run in some families. If there is a history of heart disease in your immediate family (parents, siblings, children), you should try very hard to control your modifiable risk factors.
Modifiable risk factors
What are the modifiable risk factors?
1) High blood cholesterol
Low-density lipoproteins (LDL) or "bad" cholesterol increases the build-up of fats in the arteries. This causes hardening of the arteries so that they become narrowed. The result is that the blood flow to the heart becomes blocked or reduced.
High-density lipoproteins (HDL) or "good" cholesterol carries cholesterol from the arteries back to the liver, thus preventing the build-up of fats and formation of plaque in the arteries.
High blood cholesterol does not cause symptoms. It is therefore important to check your cholesterol levels regularly. This means once a year for a normal person wishing to monitor his cholesterol and more frequently as advised by physicians for those who have elevated levels or risk factors.
If your cholesterol level is high, it can be lowered to reduce your susceptibility to coronary heart disease.
The desirable level of cholesterol depends on your pre-existing risk for coronary heart disease. The goal is to keep your total cholesterol level as low as possible.
2) High Blood Pressure / Hypertension
Hypertension is one of the major risk factors for coronary heart disease and cerebrovascular disease such as stroke. You should check your blood pressure at least once a year.
Like high blood cholesterol, hypertension usually occurs without any symptoms. If left untreated, it can result in damage to the heart and blood vessels, eventually leading to stroke, heart attack or renal failure. Occasionally, when one's blood pressure is extremely high, the person may experience headaches, dizziness or alterations in vision.
Normal blood pressure may vary from 90/60mmHg to 120/80mmHg in a young healthy person. Hypertension is present when a person's blood pressure is persistently above 140/90mmHg.
If you have diabetes or kidney disease, you must try to keep your blood pressure at around 120/80mmHg. This is because even a marginally higher blood pressure will increase your risk of developing complications.
Marginally elevated blood pressure may normalize when you lose weight, exercise more and reduce salt intake. If these measures are not successful, then medication may be needed. However, once medications have been started, it is essential to continue with the treatment, which should be complemented with a healthy lifestyle.
Treatment of hypertension for most people is lifelong.
3) Diabetes mellitus and abnormal blood glucose (sugar) levels
Diabetes mellitus is a chronic illness. People with diabetes are 2 to 4 times more likely to develop coronary artery disease and stroke. It is often associated with other cardiovascular risk factors, such as high blood pressure, increased total cholesterol and triglyceride levels, decreased HDL-cholesterol levels and obesity.
The basic treatment strategy is to maintain good control over the amount of glucose in your blood. Maintaining a healthy weight, a balanced diet and a regular exercise routine can prevent the onset of diabetes mellitus.
Before the onset of menopause, many women appear to be partially protected from coronary heart disease, heart attack and stroke by natural oestrogen.
A woman's oestrogen level is highest during her childbearing years and declines during menopause. However, women lose their natural oestrogen as they age and this may contribute to a higher risk of heart disease and stroke after menopause.
After menopause, women have a more adverse biochemical profile, which includes increased triglyceride, very low-density lipoprotein (VLDL) cholesterol levels or increased LDL or "bad" cholesterol levels. These changes increase women's risk of developing coronary heart disease.
If menopause is caused by surgery to remove the uterus and ovaries, the risk rises sharply. If menopause occurs naturally, the risk rises gradually. However, routine hormone replacement for women who have undergone natural menopause does not prevent heart disease.
5) Obesity and being overweight
People who have excess body fat, especially located around the waist, are more prone to developing heart disease and stroke even if they have no other risk factors.
Excess weight increases the strain on the heart and raises blood pressure, blood cholesterol and triglyceride levels, while lowering HDL ("good" cholesterol) levels. This may also be associated with the development of diabetes mellitus.
Family history and environment both play a part in determining obesity. Body fat increases when you consume more food calories than you require over a long period of time. Physical inactivity and a high fat diet also contribute to obesity.
Similarly, weight control (fat loss) is possible by decreasing food intake while increasing physical activity. If you use more calories because of increased physical activity, a gradual decrease in body weight will take place. Weight loss leads to a decrease in blood pressure, blood glucose and blood cholesterol levels.
6) Physical inactivity
An inactive lifestyle is a risk factor for coronary heart disease.
Regular physical activity helps prevent heart and blood vessel disease. Moderate-intensity activities will help if they are done regularly and over a period of time.
Regular exercise may also lead to improvement in other cardiovascular risk factors, such as weight loss, lower blood pressure, decreased stress and improved cholesterol level.
Exercise programmes should start at a slow pace initially to avoid injury to your muscle and ligaments.
While the risks of exercise are minimal, people with known coronary artery disease or those above 40 years of age who have been inactive should seek medical advice before starting a regular exercise programme.
Smoking leads to heart attack, stroke, high blood pressure, blood vessel disease, cancer and lung disease. Smokers have 2 to 3 times the risk of non-smokers of sudden cardiac death. In fact, smokers account for about 40% of deaths caused by heart disease in patients who are younger than 65 years.
When a person smokes, the nicotine in the smoke speed up his heart rate, raise the blood pressure and disturb the flow of blood and air in the lungs. The carbon monoxide in the smoke lowers the amount of oxygen carried in the blood to the rest of the person's body, including the heart and the brain. The tar and cancer-causing substances are deposited in his airways and lungs.
Smoking also causes a decrease in HDL-cholesterol.
Your blood pressure goes up momentarily when you get angry, excited, frightened or when you are under stress. If you are constantly stressed over a prolonged period, you may be at a higher risk of developing high blood pressure.
Stress affects everyone and may cause palpitation, headaches, insomnia and digestive symptoms. Prolonged stress may contribute to a heart attack.
Emotional stress and tension also cause the body to produce adrenaline, which makes the heart pump faster and harder, and may also cause the blood vessels to narrow down.
While we cannot do much about the non-modifiable risk factors, we can still work on the modifiable risk factors to reduce our risks for coronary heart disease.
Knowing and actively managing our risk factors is the best way to prevent or delay the onset of heart disease and lessening its impact on our lives.
This article was contributed by National Heart Centre Singapore (NHCS) and is part of a series on heart health.