All forms of tobacco exposure - smoking, chewing or inhaling second hand smoke - increase the risk of heart attack up to three times, according to an Article in this week’s issue of The Lancet.
Previous studies have shown that tobacco smoking increases the risk of heart disease. However, to date most of these studies have been in developed countries and few large studies have been done to examine the effects of tobacco in other geographical regions.
In the INTERHEART study, Salim Yusuf and Koon Teo (McMaster University, Ontario, Canada) and colleagues calculated the risk of heart attack for various forms of active tobacco use (both smoking and non-smoking) and second hand smoking (SHS) in all areas of the world. The study included data from over 27 000 people in 52 countries. The investigators adjusted their calculations to exclude the effect of other lifestyle factors that could affect heart attack risk, such as diet and age.