In women over 30, physical inactivity may be the greatest single contributor to heart disease risk.
Researchers followed 32,154 Australian women in three age groups: those born in 1973-1978, 1946-1951 and 1921-1926. They used a mathematical formula called population attributable risk, or P.A.R., that indicates the percentage reduction in disease that would be achieved in a given population if exposure to a specific risk were eliminated. The study was published online last week in The British Journal of Sports Medicine.
They found that the importance of the most common risk factors for heart disease — smoking, high blood pressure, physical inactivity and excess weight — varies with age.
In women under age 30, for example, the greatest contributor to heart disease is smoking. Stopping smoking would reduce the risk of heart disease in this group twice as effectively as reducing high body mass index.
But for women in their 70s, being physically active would lower the P.A.R. almost three times as much as smoking cessation, and significantly more than reducing blood pressure or achieving a healthy body weight.
“It’s a heads-up for women in their 30s, 40s, 50s to get moving,” said the lead author, Wendy J. Brown, a professor of health at the University of Queensland. “And if they are moving, to move more.”
By Nicholas Bakalar