Secondhand smoke more harmful to obese.

• Position: Toxicology - Brief article

New insights into why obese cigarette smokers experience a high risk of heart disease suggest that cigarette smoke affects the activity of hundreds of key genes that both protect the heart and lungs and expose them to damage. The study, published in Chemical Research in Toxicology, suggests that the effects especially may be profound in obese nonsmokers who inhale "side-stream smoke" from cigarettes smoldering nearby.

Diana J. Bigelow and her colleagues in the Biology Division at Pacific Northwest National Laboratory, Richland, Wash., point out that active smoking doubles the risk of heart disease, while secondhand smoke exposure increases this risk by about one-third. They set out to gain more information on why the risks especially are high among people with obesity.

The report describes how mainstream smoke and, to a greater...