The most common type of cardiovascular disease - ischemic heart disease -affects men and women equally. While arteries may stiffen with age, thus contributing to risk of cardiovascular disease in older Canadians, and while heredity may also play a part, the majority of cases of cardiovascular disease relate to modifiable risk factors.
The major modifiable risk factors include:
Smoking contributes to the development of blocked arteries, increases the risk of blood clots, reduces oxygen in the blood and increases blood pressure. Smoking and/or exposure to other people smoking are harmful to health in general and increase the risk of a person developing ischemic heart disease and stroke. More than 37,000 Canadians die prematurely each year from tobacco use. Non-smokers can also die prematurely from second-hand smoke, and smoking nearly doubles the risk of a person having a stroke.
Stopping smoking provides immediate and long-lasting benefits. The risk of heart attack starts to go down within hours. Within 15 years, the risk of a heart attack for former smokers is the same as for those who never smoked at all.
People who are physically inactive have twice the risk of having heart disease and a stroke. Unfortunately more than half of Canadians report being inactive. Physical activity after a heart attack is important because it reduces the risk of having another such event and it improves the chances of survival.
A minority of Canadians report eating fresh fruits and vegetables in the amounts that are recommended in Canada's Food Guide. Some 56% of Canadians eat less than 5 servings of fresh fruit and vegetables per day. Fresh fruits and vegetables can protect the heart and blood vessels. They provide fibre and contain anti-oxidants, substances which work against the development of blockage in the arteries.
Cholesterol is one of the fats in the blood that contribute to the growth of all cells in the body. Cholesterol is manufactured by the body in the liver, with a smaller amount coming from fatty food. Too much cholesterol can lead to blockage of arteries.
There are two main types of cholesterol:
While triglycerides are not a type of cholesterol they are, however, a type of fat that is found in the blood. High triglycerides are linked with excess weight, excess alcohol consumption and diabetes.
Blood pressure (hypertension) is a measure of the pressure or force of blood against the walls of the blood vessels called arteries. The top number of a blood pressure reading represents the pressure when the heart contracts and pushes blood out (systolic) and the bottom number is the lowest pressure when the heart relaxes between beats (diastolic).
Blood pressure that is consistently more than 140/90 mmHg is considered high. For those living with diabetes, 130/80 mmHg is considered high.
Over time high blood pressure can damage blood vessel walls causing scarring that promotes the build-up of fatty plaque, a substance that can narrow and eventually block arteries. Fatty plaque also strains the heart, initially causing a thickening of the heart muscle and eventually causing the heart to weaken. Very high blood pressure can cause blood vessels in the brain to burst resulting in a stroke.
In addition to being one of the most important risk factors for cardiovascular diseases, high blood pressure is also the number one modifiable risk factor for stroke. In Canada more than 4.6 million people have been diagnosed with hypertension and possibly as many again remain unaware that they may have it. More than 90% of individuals aged 55 to 65 with normal blood pressure are expected to develop high blood pressure over their lifetimes.
In 2007, 21 million visits to community physicians were due to high blood pressure. In addition, there has been an increase in prescriptions for high blood pressure medication. Direct costs of high blood pressure in Canada are estimated to be approximately $2.3 billion per year.
With mounting evidence linking over-consumption of dietary sodium with the development of high blood pressure, in 2007 the Government of Canada established a multi-stakeholder Working Group on Dietary Sodium Reduction. The mandate of the Working Group is to develop, implement and oversee a population-health strategy for the successful reduction of the sodium content in the diets of Canadian. The strategy will be available in the spring of 2009. Also, the new edition of Canada's Food Guide describes the benefits of eating well and being active, and emphasizes the importance of avoiding foods high in sodium, sugar, saturated and trans fats to prevent cardiovascular diseases and hypertension.
Recently PHAC provided support to Blood Pressure Canada for the development of a knowledge exchange portal, and knowledge development and translation initiatives on dietary sodium reduction. Through this project clinicians, scientists, policy makers and the Canadian public will have access to the most current scientific information on dietary sodium reduction.
Everyone understands the concept of stress yet the concept is hard to describe and even harder to measure. While stress can sometimes be a good thing, too much stress can be harmful, increasing the risk of heart disease and stroke. The cause of the stress (stressor) is not as important as the individual response to it. Learning to cope with stress is very important to the prevention of hypertension, especially if the stressor cannot be eliminated or changed.
Many life events such as moving, leaving school, changing jobs, and experiencing losses can cause stress. Daily frustrations, such as being stuck in traffic, facing deadlines or experiencing conflicts can also bring on stress. Managing stress effectively starts with identifying and then dealing with stressors.
The relationship between stress and heart disease and stroke is not completely clear, mainly because of some difficulties in measuring stress. It is certain, however, that high levels of stress or prolonged stress may result in high blood cholesterol, increased blood pressure or disturbances in heart rhythm.
When life is full of stress, it can be hard for the stressed person to lead a healthy lifestyle. Instead of being physically active to relieve stress, some people respond by overeating, eating unhealthy foods, consuming too much alcohol or smoking. Such reactions can increase the risk of developing heart disease and stroke. Responding to stress with anger can also be harmful. People who are prone to anger are also more likely to turn to unhealthy behaviours, such as smoking, excessive alcohol consumption and overeating.
Diabetes develops when insulin does not control the level of sugar in the body, either because not enough insulin is produced or the body does not react properly to the insulin that is produced. Insulin is required to break down sugar for energy.
Diabetes increases the risk of high blood pressure, coronary artery disease and stroke particularly if the blood sugar levels are poorly controlled. It can result in poor circulation caused by damage to the blood vessels.
There are three types of diabetes as follows: