August 25, 2006

Study stokes passive smoking’s risks

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Incoming medical student Alan Powers is happy to receive his white coat from VUSM Dean Steven Gabbe, M.D.
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Study stokes passive smoking’s risks

The dangers of breathing another person's smoke are well known — but not universally accepted.

In 2003, researchers reported finding no “causal relation” between environmental tobacco smoke and tobacco-related mortality among 118,000 California residents who had enrolled in a cancer prevention study four decades earlier.

In the current issue of the British Medical Journal, however, researchers at Vanderbilt University Medical Center report that passive smoking significantly increased the risk of death among more than 72,000 participants in the Shanghai Women's Health Study who had never smoked themselves.

The mortality analysis showed that women whose husbands smoked had a significantly increased risk of dying from cardiovascular disease and stroke, while women exposed to smoke in the workplace had a significantly increased risk of dying from cancer, particularly lung cancer.

This paper confirmed findings reported by the Vanderbilt group last year from an analysis of more than 60,000 non-smokers who participated in the Shanghai Women's Health Study. In that study, women whose husbands smoked 20 cigarettes or more a day had a 62 percent greater chance of suffering a stroke than did those whose husbands had never smoked.

The Shanghai Women's Health Study was launched in 1996 to explore the role of diet, exercise and other environmental factors in the development of cancer and other chronic diseases.

“This population is very unique,” said the lead author, Wanqing Wen, M.D., research assistant professor of Medicine in the Vanderbilt Center for Health Services Research.

While 60 percent to 70 percent of Chinese men smoke, the rate among women in the Shanghai cohort is less than 3 percent, Wen said. Smoking also is allowed in most workplaces in China. “It's ubiquitous,” he said.

Wen, a native of Hunan Province, joined the Vanderbilt faculty in 2000. His Vanderbilt co-authors were Xiao Ou Shu, M.D., M.P.H., Ph.D., professor of Medicine; Gong Yang, M.D., M.P.H., research assistant professor of Medicine; and Wei Zheng, M.D., M.P.H., Ph.D., professor of Medicine and Ingram Professor of Cancer Research.

Shanghai Cancer Institute physicians Yu-Tang Gao, Qi Li and Honglan Li also contributed to the study. The study was funded by the National Institutes of Health.