Other factors are involved in your heart’s health. They are called coronary risk factors. This term is used because the arteries that supply blood directly into the heart muscle itself are called coronary arteries (see diagram at right).
One in four Canadians will develop some form of heart disease during their lifetime. The most recent Canadian statistics (Stats Can 2004) show that about 75,000 Canadians had heart attacks that year. Around 19,000 of those died.
However, the good news is that the incidence of heart disease and stroke has significantly reduced over the last several decades. The percentage of Canadians suffering from it has gone down 25 per cent in the last 10 years, 50 per cent in the last 20 years, and 70 per cent in total since 1956.
These numbers show that we are more aware of heart disease and more aggressive about making our lifestyles healthier. Even so, two out of every three Canadians have one or more coronary artery risk factors. As the trends show, you can significantly reduce your risk of having heart disease by minimizing factors that lead to an unhealthy heart.
The information here can help you to understand your risk factors and keep your heart healthy. A tool that can estimate your chances of having heart trouble is below. Using it, you can compare your risk of heart disease to the average risk of a healthy individual your age and gender.
Table 1: Coronary Artery Risk Factors
|Moderate Risk||High Risk|
|Family history of heart disease||Personal history of heart disease|
|High blood pressure||Very high blood pressure|
|Total cholesterol of 5.2 to 6.8 mmol/L||Total cholesterol over 6.8 mmol/L|
|LDL cholesterol of 3.4 to 4.1 mmol/L||LDL cholesterol over 4.1 mmol/L|
|HDL cholesterol under 1.0 mmol/L||HDL cholesterol under 0.9 mmol/L|
|Triglycerides over 2.26 mmol/L||Triglycerides over 5.65 mmol/L|
|Fasting blood glucose over 6.3 mmol/L||Fasting blood glucose over 6.6 mmol/L|
|Smoking – pipe or fewer than 10 cigarettes a day||Smoking – more than 10 cigarettes a day|
|Not much exercise||No exercise at all|
|Overweight by 10 to 20 per cent||More than 30 per cent overweight|
|High stress levels||High stress levels|
Table 1 lists the most important coronary artery risk factors. While you really cannot change some, your actions make a difference with most.
Your age, gender and family history are factors you cannot change. The possibility of heart disease increases with age, especially if you are male or have several blood relatives with heart disease. If you have had certain previous problems with your heart, like angina (chest pain) or an actual heart attack, your risk naturally increases. If you have diabetes, you probably know you are at more risk of damage to your coronary arteries.
Blood pressure is the force exerted on the walls of the arteries as blood passes through. Blood pressure is measured at its maximum and at its minimum. The maximum is the systolic pressure, when the heart chambers are contracting. The minimum is the diastolic pressure, when the heart chambers relax.
High blood pressure is one factor that you and your doctor can successfully deal with together. High blood pressure is defined as systolic blood pressure of 140 mm (Hg) or greater or diastolic blood pressure of 90 mm (Hg) or greater. Weight control, good nutrition, sufficient exercise, limiting alcohol and salt, and not smoking go a long way for most of us. All too often, medication is also required to lower blood pressure to an acceptable level.
Over five million Canadians have high blood pressure. Unfortunately, many needlessly suffer from the effects. Studies have shown that, even in North America, high blood pressure is treated adequately only about 16 per cent of the time.
Only about half the population with high blood pressure has it checked frequently enough to know that it is elevated. Not everyone with known high blood pressure gets the right treatment. Not all of those getting the right medication take it faithfully enough for it to help.
Persistent, uncontrolled high blood pressure is very hard on the walls of arteries. It can significantly reduce the amount of blood pumped through them to your organs. Lowering your blood pressure protects other important arteries like those to your kidneys and your brain.
Get your blood pressure checked periodically. This can be done at most local pharmacies and at some fire stations. If your reading is high, visit your doctor. Some people become nervous in the doctor’s office. If this is true for you, it may be more reliable to check your blood pressure with your own equipment at home.
Your body uses substances known as lipids to produce healthy cell membranes, nerves and certain hormones. Lipids are blood fats, including cholesterol and triglycerides. The body coats these fats with protein so they can be carried in the blood. Fats linked to proteins are called lipoproteins.
However, lipoproteins have a down side. Higher levels of certain types increase the risk to the health of your heart. Doctors commonly measure cholesterol and triglycerides to estimate the risk from fats in your blood stream. Your doctor may also want to know your levels of LDL (low density lipoproteins), VLDL (very low density lipoproteins), and HDL (high density lipoproteins).
Some people call LDL ‘bad cholesterol’ and HDL ‘good cholesterol.’ High LDL levels contribute to hardening of the arteries. This is less likely to happen if you have high HDL levels.
Your blood cholesterol level is one risk factor you can usually reduce. You can lower your blood cholesterol levels by reducing to the ideal body weight and having less fat in your diet.
If this does not improve the situation, your doctor may recommend you take medication to lower your cholesterol. This is most likely if your total cholesterol is over 7.0 mmol/L or your LDL remains over 4.9 mmol/L. Medication is usually recommended for people with less severe elevations of cholesterol who have already had coronary artery problems.
Triglycerides are carried in very low density lipoproteins. They are also associated with risk of coronary heart disease. Changing your lifestyle with exercise, weight control and diet care will often deal with moderately elevated levels of triglycerides. Your doctor may suggest medication if your triglyceride levels are over 5.0 mmol/L. Again, medication may be considered for those with milder elevations who have had previous coronary problems.
Another risk factor is fasting blood glucose. This blood test is often used to predict the likelihood of diabetes. Diabetes seriously increases the risk of coronary artery disease. It has been estimated that more than 80 per cent of people with diabetes will die from some form of heart or blood vessel disease.
Smoking is a major risk factor. It causes one in every five deaths due to heart disease. In spite of this statistic, every day more young Canadians become smokers. The U.S. Surgeon General has called smoking “the most important of the known modifiable risk factors for coronary heart disease.” The risk of death from coronary heart disease increases up to 30 per cent among non-smokers exposed to smoke at home or at work. Smokers are more likely to die from their first heart attack than are non-smokers.
Studies have shown that as many as 60 per cent of adults do not get the recommended amount of physical activity. Regular aerobic exercise can help control abnormal cholesterol, diabetes, blood pressure and obesity. HDL levels can be improved by regular physical activity.
Physical activity does not need to be strenuous to be effective. Even moderate exercise can reduce the risk of heart disease, as long as it is carried out for at least 30 minutes, three to four times per week. Such activities as pleasure walking, tennis, dancing and a variety of home exercise can be very beneficial.
Almost half of all Canadians are overweight. Those who are overweight are more likely to develop heart disease even if they have no other risk factors. Obesity (being 20 to 30 per cent over ideal body weight) can increase your triglycerides, lower HDL and increase VLDL cholesterol. This is the wrong direction for all of these factors. Losing just seven to 11 pounds (three to five kilograms) can reduce your triglyceride and cholesterol levels.
The final risk factor to discuss is stress. The American Heart Association says that stress is a contributing factor to heart disease. Some 80 per cent of people who suffer heart attacks believe stress contributed to their condition. Whether the problem is stress itself, or what it leads us to do, is still an issue of debate. People may increase their risks by turning to eating, smoking or drinking when their stress levels rise.
If you are a woman, you probably do not worry that much about having heart disease. You may worry more about getting breast cancer. The fact is heart disease claims five times as many women as breast cancer. Although women develop heart problems seven to eight years later in life than men, they are less likely to survive their first heart attack.
Estrogen’s effects protect women until menopause. After age 65, women’s heart attack risk becomes almost equal to that of men. Hormone replacement after menopause can maintain some of a woman’s protection from coronary heart disease.
Most risk factors for heart disease are the same for women and men. A few differences do exist. Smoking doubles the risk of heart attack for both women and men. However, women who smoke and have also used oral contraceptives are 39 times as likely to have a heart attack as women who have done neither. Women with diabetes have a higher risk of heart disease than men who have diabetes. Diabetes doubles the risk of a second heart attack in women, but not in men.
Fortunately, coronary risk factors in women are now receiving more attention from both the medical profession and women themselves. In the past, through lack of education, there was a tendency to downplay or ignore these risks.
The First Heart Attack Risk Test (download pdf here) is a quick assessment tool. It is intended only to provide you with an approximation of your risks. A more accurate assessment of your risk can be found using the Alberta Health Services Heart Attack Risk Calculator (see Internet Resources).
Take the time to determine whether your heart is at low, medium or high risk. If the test results indicate you are at low risk, keep doing all of the things you are doing right. If, on the other hand, the answer is medium or high risk, identify the coronary artery risk factors that apply to you. Lifestyle changes can help you to start reducing those risks. However, you may find you want more advice regarding your situation. Your family doctor will be able to put your risk factors into perspective and give more information if you need it. A list of excellent, easy to obtain resources can be found below.