Secondhand Smoke Raises Stroke Risk for Spouses

TUESDAY July 29, 2008 -- Nonsmokers who are married to smokers run a significantly higher risk for experiencing a stroke, a new study suggests.

Researchers also found that ex-smokers married to men and women who still smoke carry an even greater risk for stroke. However, nonsmoking spouses of former smokers do not appear to bear any higher risk for stroke than those married to someone who had never smoked.

"This adds to the growing evidence that secondhand smoke is bad for you, and I hope that it will help people who want to stop smoking to know that it will probably be good for their spouse's health, too," said Maria Glymour, an assistant professor of society, human development and health at the Harvard School of Public Health in Boston. Glymour is also a health and society scholar in the department of epidemiology at Columbia University in New York City.

She and her team were expected to publish the findings in the September issue of the American Journal of Preventive Medicine.

Glymour pointed out that hers is one of the few studies to specifically focus on the potential link between secondhand smoke and stroke risk. She further noted that indications that the association is real and strong stem from a larger National Institute on Aging research effort that tracked a wide range of social factors and their relationship to stroke risk.

In that study, all 16,000-plus participants were 50 and older and married. All were categorized according to smoking habits, and observed for stroke incidence over an average of about nine years between 1992 and 2006.

Nonsmokers married to a current smoker were found to have a 42 percent increased risk for stroke, compared with those married to spouses who had never smoked. Similarly compared, ex-smokers married to a current smoker had a 72 percent increased risk for stroke.

As for those married to ex-smokers, Glymour and her team only observed that the former smokers had kicked their habit at some point one to 50 years before the start of the study. They could not pinpoint exactly how much time would need to elapse after a smoking spouse quits before their husband or wife's stroke risk fully dissipated.

"But we think the risk to the spouse probably starts to decline right away," Glymour noted. "And that would be consistent with what we already know about stroke and active smoking, which is that if you stop smoking your own health risks decline quickly."

Thomas J. Glynn, director of cancer science and trends at the American Cancer Society, said that he found Glymour's analysis to be "very reasonable."

"I agree that one might expect a fairly steep drop-off in stroke risk for the spouse once the smoking partner quits," he said. "We know, for example, that although it takes about 15 years of not smoking to halve your risk for lung cancer, with heart disease it may take not much more than one to two years of cessation to cut back one's own risk to basically that of a nonsmoker, depending on how long you had been smoking. So, this conclusion makes sense."

"And, in general, I would say that this study provides further valuable evidence of the general dangers of secondhand smoke, and, in particular, the great and often over-looked danger of heart disease, he said. And, of course, it emphasizes the need for anyone who smokes to stop smoking, and at a minimum to establish smoke-free zones in the home, or not smoke in the home at all."

More information

For more about secondhand smoke and health risks, visit the American Lung Association.

Posted: July 2008


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