U.S. death rates from coronary disease have dropped in the last two decades, but may be increasing in women with ages between 35 and 44 according to a new study.

Between 1997 and 2002, the rate of death from coronary disease in women increased by an average of 1.3 percent annually. This percent is statistically significant and a legitimate cause for concern said Dr. Earl S. Ford, a medical officer in the U.S. Public Health Service and a study co-author.

"Young adults should take stock of their lifestyles. If you're smoking, you should quit. If you're doing less than 30 minutes of physical activity per day, it's time to find ways to be more active. If you need to lose weight, you should burn more calories than you take in," Ford said in a statement.

Researchers at the Centers for Disease Control and Prevention in Atlanta and Dr. Simon Capewell, of the University of Liverpool used U.S. coronary data from 1980 to 2002.

The study found that the death rate from coronary disease fell by 52 percent in men and 49 percent in women from 1980 to 2002. This should be pleasing, but according to the report, the average annual rate of death from coronary disease leveled in men with ages between 35 and 54 and increased in women with the same age from 2000 to 2002.

If included all patients 35 and older, the results look a little better. The coronary disease death rate among men 35 and up declined by 2.9 percent during the 1980s, 2.6 percent a year during the 1990s and 4.4 percent a year from 2000 to 2002. For women aged 35 and over, things look a little different. The annual coronary death rate declined by 2.6 percent during the 1980s, 2.4 percent during the 1990s and 4.4 percent from 2000 to 2002.

"We can't tie these rates to anything in particular, so we have to speculate," Ford said.

As the doctor said, obesity, diabetes, high blood pressure and lack of physical activity numbers among the speculated causes for coronary disease. Smoking is also a major concern for scientists.

"There is a major epidemic of obesity in the United States. There have been no major decreases in smoking. [Changes in] cholesterol levels are also flat. Also, hypertension in the United States is something people have to pay more attention to," Ford said.