Grant: Operating Grant

There are 5 million smokers in Canada. Cigarette smoking is known to cause hardening of the arteries that carry blood to the body. This hardening increases the risk of heart attacks and strokes. We know that stopping smoking reduces the risk for heart attacks and strokes. However, we do not know if stopping smoking improves the hardening of the arteries. We also do not know how long it takes for the hardness of the arteries to get better after quitting. We propose a study that has two parts. In part 1, we will test the immediate and long-term effects of smoking on hardening of the arteries. In part 2, we will follow three groups of healthy individuals every 6 months for a period of 2 years. These groups will be ex-smokers who recently stopped smoking, never smokers, and current smokers. In both part 1 and 2, we will test: a) the blood of the subjects, and b) the hardening of the arteries at rest and when the body is stressed, as in exercise. We will use a simple and safe technique to test the hardness of the arteries. People with hard arteries may have no problem at rest, but they may have difficulty to do demanding activities. This difficulty may only show after exercise. This is why we will test the hardening of the arteries after exercise. The results of this study may help us understand how smoking harms the arteries, and how stopping smoking helps the arteries get better. We propose a new way to uncover the harm that smoking causes to the arteries. This new way is to study the hardness of the arteries after exercise. Using this new approach, doctors will be able to better assess the risk of each person who is a smoker or ex-smoker to have a heart attack and stroke.