Women who are otherwise healthy, but have low levels of physical activity and high levels of weight, generally have less favorable heart health than their leaner, more active counterparts, Boston-based researchers report in today’s issue of the Journal of the American Medical Association.

“The important observations from our study are that even in healthy women both fitness and fatness are very important for heart health,” Dr. Samia Mora from the Center for Cardiovascular Disease Prevention at Brigham and Women’s Hospital told Reuters Health.

The message, therefore, for women who want to protect themselves from having a heart attack, the number one killer of women, “is to get out and walk, be active 30 minutes each day most days of the week, and lose those 10 lbs or more if you need to, if you want to protect yourself against heart attack and stroke,” Mora said.

More than half of the US population falls short of recommended levels of physical activity and 65 percent are overweight or obese, with women outnumbering men. Both increased body weight and a sedentary lifestyle are strong predictors of heart disease, as well as diabetes and death.

Among 27,158 apparently healthy US women, Mora’s team found that lower levels of physical activity and higher levels of body weight were independently associated with adverse levels of nearly all of the 11 lipid and inflammatory biomarkers measured. These biomarkers are related to cardiac risk and may play a role in the development of atherosclerosis, also referred to as “hardening of the arteries.”

For example, inactive overweight women had higher levels of potentially harmful C-reactive protein, a blood protein that signals ongoing inflammation, and higher levels of “bad” LDL cholesterol and lower levels of “good” HDL cholesterol.

Compared with normal weight women, “women who were overweight or obese had 2 to 10 times increased levels of risk factors that increase women’s risk for heart attack and stroke, such as cholesterol and inflammation,” Mora reported. Women who were physically inactive, whether they had normal weight or elevated weight, also had 5 to 50 percent higher levels of these risk biomarkers, she added.

A high body weight was more strongly related to adverse cardiovascular biomarker levels that physical inactivity. However, within body weight categories, physical activity was generally associated with more favorable cardiovascular biomarker levels than inactivity.

SOURCE: The Journal of the American Medical Association, March 22/29, 2006.