A new study finds that the life expectancy for women in 180 U.S. counties declined significantly between 1983 and 1999.

The decline averaged 1.3 years, and the 180 counties were mostly in the deep South and Appalachia. Men's life expectancy declined by 1.3 years in only 11 counties.

Researchers blame the decrease in women's life expectancy on high blood pressure as well as chronic diseases related to smoking and obesity, such as lung cancer and diabetes.

The study is based on data from the National Center for Health Statistics and the U.S. Census Bureau. It is posted in the online journal PLoS Medicine.