Release Date: February 21, 2003
BUFFALO, N.Y. -- Women already at risk of having a stroke because they smoke cigarettes increase their stroke risk three-fold if they live with a spouse who smokes, a study conducted at the University at Buffalo has shown.
The overall increase in risk of developing any form of stroke was more than three-fold in this group. On the other hand, non-smoking women whose spouses smoked did not show an increase risk of stroke.
Adnan Qureshi, M.D., lead author on the study, said a possible explanation for the increase in risk among smoking women, but not among non-smoking women, could be related to certain smoking habits.
"Spouses are more likely to smoke in proximity (the same room) to wives who smoke than to wives who do not smoke," he said. "There also is an increased likelihood that when both spouses smoke, they are less likely to spend time in a smoke-free environment.
"The findings suggest that spousal smoking exerts a negative effect on cardiovascular health of women who smoke, in addition to and independent of the classical cardiovascular risk factors."
Results of the study were presented Feb. 14 at the 28th International Stroke Conference in Phoenix, Ariz.
Several studies have pointed to second-hand smoke from spouses as a source of tobacco exposure that can increase a woman's risk of cardiovascular diseases. Qureshi and colleagues at UB set out to examine this concept in a national cohort of women who took part in the first National Health and Nutrition Examination Survey, conducted from 1971-75, and its follow-up study conducted 10 years later.
The study group consisted of 6,003 women who reported their own smoking status and that of their spouse at the initial data collection. Of this group, 2,470 were cigarette smokers; 1,970 had a cigarette-smoking spouse, while 500 did not.
Researchers compared the original data on smoking status with incidence of cardiovascular diseases and stroke that occurred among the women during the subsequent 10 years. Results showed that women smokers living with smoking spouses were at three times the risk of suffering any type of stroke and 2.3 times the risk of experiencing an ischemic stroke -- one caused by a blood clot in a blood vessel in the brain, the most common type of stroke. The risk for experiencing any type of cardiovascular disease was 2.4 times greater in this group.
These results held despite taking into account a host of conditions known to influence a person's risk of stroke: age, race, gender, obesity, hyperlipidemia, systolic blood pressure, diabetes, daily cigarette consumption and age when participants started smoking.
Additional authors on the study, all from the UB Toshiba Stroke Research Center and Department of Neurosurgery in the UB School of Medicine and Biomedical Sciences, were: M. Fareed K Suri, M.D.; Amir M. Siddiqui, M.D.; Ricardo A Hanel, M.D.; Adnan Safdar, M.D.; Jawad F. Kimani, M.D.; Andrew R. Xavier, M.D.; Abutaher M. Yahia, M.D., and L. Nelson Hopkins, M.D., department chair.
Qureshi was an associate professor of neurosurgery at UB at the time of the study. He now is director of the Cerebrovascular Program at the University of Medicine and Dentistry of New Jersey (UMDNJ) -- New Jersey Medical School.