Research around the world

The increase in disease risk that is associated with smoking is 25% greater for women 

Smoking increases women’s risk of cardiovascular disease more than it does men’s.

A new study in Italy and a US review of 86 previous trials have come to the same conclusion: the extent to which smoking increases the risk of cardiovascular diseases such as atherosclerosis and coronary heart disease is greater in women than in men.

Professor Elena Tremoli of the University of Milan (Italy) used ultrasound technology to assess the presence of wall thickening and plaques (causes of atherosclerosis) in the carotid arteries of 1694 men and 1893 women from Finland, Sweden, the Netherlands, France and Italy. Her results were presented at the European Society of Cardiology (ESC) Congress in Paris, August 2011. They showed that total tobacco exposure had more than twice the thickening effect on carotid artery walls in women than it did in men, and the effect of tobacco consumption rate (number of cigarettes smoked per day) on the progression of atherosclerosis was more than five times greater in women than in men.

“The reasons for the stronger effect of tobacco smoke on women’s arteries are still unknown,” said Professor Tremoli in a press release, “but some hints may come from the complex interplay between smoke, inflammation and atherosclerosis.” Women are usually protected against the harmful effects of inflammation, compared to men, but lose this protection when they smoke.

Meanwhile, Dr Rachel R Huxley of the University of Minnesota (Minneapolis, USA) and Mark Woodward of Johns Hopkins University (Baltimore, USA) have compared the findings of 86 different medical studies on smoking and coronary heart disease, comprising data from nearly 4 million people. They calculated an adjusted female-to-male ‘relative risk ratio’, based on relative risks of coronary heart disease in smokers and non-smokers of 1.25 – Meaning the increase in disease risk that is associated with smoking is 25% greater for women than it is for men.

“Whether mechanisms underlying the sex difference in the risk of coronary heart disease are biological or related to differences in smoking behaviour between men and women is unclear,” say Huxley and Woodward, but either way “tobacco-control programmes should consider women, particularly in those countries where smoking among young women is increasing in prevalence.” Their findings were published online by The Lancet in August 2011.

Professor Helena Teede, director of research at Jean Hailes, says “This is yet further evidence that risk factors including diabetes and smoking are bad for all but more potent in women than in men. It highlights the need for greater awareness and focused prevention strategies for women and their healthcare providers.”

Content Updated November 2011