Women Smokers Have Higher Risk of Heart Disease Than Men

From Heartwire

Michael O'Riordan

August 11, 2011 (Minneapolis, Minnesota) — A large meta-analysis suggests that the harmful effects of tobacco smoking affect men and women differently. In a study of more than two million people, researchers showed that the pooled adjusted female-to-male relative risk of coronary heart disease in smokers vs nonsmokers is 25% higher in women.

"It's an unusually large study," lead investigator Dr Rachel Huxley (University of Minnesota, Minneapolis) told heartwire . "In the main analysis, there are about 2.4 million people with data on 44 000 coronary heart disease events, and what was very nice about the study is that the results were very consistent across all of the studies. There was no heterogeneity between them, adding to the robustness of the findings. We're pretty confident that the estimate we came up with is a real approximation of the true risk."

If anything, said Huxley, the 25% increased risk might be on the conservative side. Women have not been smoking as long as men, so the true impact of smoking on women's health might not yet have manifested entirely, and women don't smoke as many cigarettes as men when they do smoke. In addition, it's still taboo for women to smoke in many cultures, and as a result women might underreport their smoking habits. "All three factors combined would suggest that the 25% is an underestimate," said Huxley.
The results of the study are published online August 11, 2011 in the Lancet.
 
Females Still a Growth Market for Tobacco Companies
In the analysis, the researchers performed a systematic review and meta-analysis of prospective cohort studies published between 1966 and 2010. Studies that stratified by sex with measures of relative risk for coronary heart disease and current smoking compared with not smoking were included in the analysis.

 

As we all know, prevention is far better and far easier than trying to cure somebody of a habit.

In the 75 cohorts, which included 2.4 million participants, the pooled adjusted female-to-male relative risk ratios of smoking compared with not smoking for coronary heart disease was 1.25 (95% CI 1.12–1.39, p<0.0001). The relative risk ratio increased by 2% for every additional year of study follow-up, a finding that suggests the longer a woman smokes, the greater her risk of developing coronary heart disease compared with a man who has smoked the same length of time.
"If you looked at some countries, such as Asian-Pacific countries, this is still a growth market for tobacco companies, because the prevalence of smoking in women is still in the single digits," said Huxley. "For example, in China, about 60% of men smoke, whereas just 4% to 9% of women smoke. Tobacco-control programs really need to develop a female perspective to dissuade women from starting to smoke in the first place, because women often find it more difficult to quit smoking compared with men."

In an editorial accompanying the published study [2], Drs Matthew Steliga and Carolyn Dresler (University of Arkansas Medical Sciences, Little Rock) point out that coronary heart disease is predicted to remain the leading cause of death globally and is expected to cause approximately 14% of deaths annually by 2030. Most of coronary heart disease is attributable to lifestyle-related factors, including smoking.
"Thus, a large proportion of the most common cause of death worldwide is attributable to behavior or addiction," they write. "Although some people might view this statistic as discouraging, it can also be seen as a great opportunity to reduce the burden of disease through behavior modification and smoking-cessation programs."
The editorialists note that national and international organizations such as the International Network of Women Against Tobacco and the World Health Organization Tobacco Free Initiative are important reference organizations that can help promote more effective tobacco cessation in women.
To heartwire , Huxley said that an understanding of sex differences in smoking-cessation initiatives has not been fully explored. However, researchers are aware there are differences in smoking-related behavior between men and women. Men, for example, start smoking at a younger age, smoke more cigarettes than women, and always have a higher smoking prevalence across different age groups, the lone exception being adolescent and teenage girls.
"That's a particular concern, because more young girls will start to smoke than young boys, so we really do need to develop effective campaigns that can dissuade young girls from starting in the first place," said Huxley. "As we all know, prevention is far better and far easier than trying to cure somebody of a habit."