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Heart disease risk higher for female smokers, study says

A woman is seen smoking in this file photo.

August 11, 2011 12:00:00 AM PDT
Women who smoke may have a 25 percent greater risk of developing heart disease than men who smoke, according to a new study of nearly 4 million people.

Scientists gathered data from 75 studies that looked at the risk of heart disease between smokers and nonsmokers.

Researchers don't know the reason for the higher risk.

But they think there are biological differences in how women's bodies react to cigarette smoke compared to those of male smokers.

The report is in the online edition of "The Lancet."