Houston: If you are a smoker and under the age of 40, you are more likely to have a heart attack than your non-smoking counterpart.

According to a research in Tobacco Control and People, under the age of 40, who smoke, are five times as likely to have a heart attack as non-smokers of the same age.

The study was conducted to know if there was risk of heart disease to other age groups other than the older smokers.

The findings are based on data from the World Health Organisation's international monitoring study of cardiovascular disease (MONICA) and risk factors.

MONICA involved participants between the ages of 33 and 64 from 21 countries. The researchers assessed all nonfatal episodes of heart disease occurring between 1985 and 1994. These amounted to 18,762 'events' in men and 4047 in women.

Rates of smoking, collected as part of risk factor surveys, were lowest in Auckland, New Zealand (18 per cent) and highest in Beijing (65 pc).

But 80 per cent of those who had a nonfatal heart attack between the ages of 35 and 39 were smokers.

Men aged between 35 and 39, who smoked were almost five times as likely to have a nonfatal heart attack as their non smoking peers. The impact was even greater among women in the same age band, who smoked. They were over five times as likely to have a nonfatal heart attack.