Young female smokers are nearly 13 times more likely to suffer a serious heart attack than non-smokers, a new study has found.
According to the Daily Mail, women under 50 were at the highest risk compared to both non-smokers and male smokers of the same age, according to British researchers. Male smokers aged 18 to 50 are 8.5 times more likely to suffer a heart attack than non-smokers of the same age, significantly lower than women.
Previous studies have revealed the impact of smoking on a higher risk of heart attacks. However, this is the first to establish a difference in gender.
The research, carried out at the University of Sheffield and South Yorkshire Cardiothoracic Centre (SYCC), involved nearly 3,000 patients undergoing treatment for acute ST-segment elevation myocardial infarction or STEMI - a medical term for a major heart attack - at SYCC.
Researchers have yet to establish the reason for the gender divide, and say they were surprised at the results. "The finding that younger women [those under 50] had a significantly greater likelihood of a major heart attack than younger men was a surprise as there is a general belief that cyclical female hormones provide a degree of cardiovascular protection," said Dr Ever Grech, consultant interventional cardiologist at Sheffield Teaching NHS Foundation Trust.
"However, our study indicates that if women smoke, this protection is easily overridden. This study also showed that when hormonal protection is no longer present in post-menopausal women, there was an even greater gender difference in heart-attack risk between male and female smokers."
While women under 50 ran the highest risk, the gender divide was greatest in older smokers.
Women smokers aged 50 to 65 are 11 times more likely to have a heart attack, while men of the same age are only 4.6 times more likely than their non-smoking peers.
Authors of the study said this could be explained by the fact that men of this age group are more likely to suffer heart attacks than women regardless of whether or not they smoke.
Dr Grech added: "The reasons for the gender differences in heart-attack risk across all age groups are unclear and likely to be complex. One possible theory is that female coronary arteries are smaller in calibre and may be more prone to complete blockage when blood clots form over pre-existing fatty deposits within the artery wall.
"There may be other factors too, but the end result is a very serious and life-threatening heart-attack event. Our previous study has shown that 50 per cent of these are directly attributable to smoking and are therefore readily preventable."
Regardless of age or gender, smokers were found to be five times more likely to suffer an acute heart attack. Previous studies have found current smokers to be some ten to 11 years younger than former or non-smokers when they suffer a STEMI.
Current smokers and former smokers are also twice as likely as those who have never been a habitual smoker to have had any previous coronary heart disease before their heart attack.
The research was presented at the American College of Cardiology's annual Scientific Sessions in Washington DC.