Women who smoke tend to have heart attacks earlier in life than women who don't smoke, negating any natural protection from heart disease, the Associated Press reported Sept. 17.

Researchers from Norway studied 1,784 patients admitted for a first heart attack. After adjusting for various heart risk factors, they found that the women who smoked had heart attacks nearly 14 years earlier than women who didn't smoke, compared with male smokers whose first heart attacks typically occurred 6 years earlier than nonsmokers.

In research presented to the European Society of Cardiology, researcher Morten Grundtvig of the Innlandet Hospital Trust in Lillehammer said that female smokers might experience earlier menopause, leaving them without the protective effect of hormones like estrogen. The increase in female smokers means that doctors can expect to see more heart disease in women, Grundtvig added.

The differences in the effect of smoking on the sexes "are profound," noted Robert Harrington, a professor of medicine at Duke University and spokesman for the American College of Cardiology. "Unless women don't smoke or quit, they risk ending up with the same terrible diseases as men, only at a much earlier age," Harrington said.

Previous studies investigating gender and smoking risks have been inconclusive. Doctors have yet to determine gender differences in the effect of other cardiac risk factors like cholesterol and obesity.