Cigarette smoking increases the risk of brain hemorrhage, and the risk persists even after quitting, evidence from a new study by UB stroke researchers shows.

In their case-control study, they found that both current smoking and previous smoking were associated with a significantly increased risk of subarachnoid hemorrhage-bleeding into the space between the middle and inner linings of the brain.

The study was presented in Fort Lauderdale last week at the American Heart Association International Joint Conference on Stroke and Cerebral Circulation.

"People need to be aware that once they take up smoking, they are facing a potentially irreversible risk for subarachnoid hemorrhage," said Adnan I. Qureshi, assistant professor of neurosurgery and lead author.

"The study points out the important role of a potentially modifiable risk factor for brain hemorrhage. Unfortunately, the risk does not appear to change after quitting cigarette smoking. Therefore, the only effective way to reduce the risk is to avoid smoking altogether."

Less common than stroke caused by blocked arteries, this type of hemorrhage accounts for 5 percent to 10 percent of strokes. It may occur without warning and often is fatal.

Qureshi and colleagues affiliated with UB's Toshiba Stroke Research Center and Johns Hopkins medical institutions reviewed the medical records of 323 patients admitted to The Johns Hopkins University Hospital between January 1990 and June 1997 with a diagnosis of subarachnoid hemorrhage. They compared data on risk factors for stroke from these cases with data from matched controls selected from the Third National Health and Nutrition Examination Survey, a representative sample of the U.S. population.

Only 93, or 28 percent, of the patients were men, an indication that this brain event is much more common among women. Forty-six percent of the patients were smokers at the time of the stroke, while 39 percent had smoked in the past, according to their medical records. The average age was 52: this type of stroke occurs most often between the ages of 35 and 60.

Analysis of data from cases and controls showed that current smokers were twice as likely to experience a subarachnoid hemorrhage than persons who had never smoked. The risk for smokers who had quit was similar to those who were actively smoking.

"Our findings support previous research showing that smoking increases the risk of this type of stroke," Qureshi said. "It also shows that the risk persists, even after people quit. The message is, of course, that people should not begin to smoke if they want to avoid this and other health risks associated with smoking."

Additional researchers on the study were Abutaher M Yahia, M. Fareed K. Suri, Zulfigar Ali, Lee R. Guterman and L. Nelson Hopkins, all of UB, the Toshiba Stroke Research Center and Kaleida Health, and Rafael J. Tamargo of the Johns Hopkins medical institutions.