By Allison Bond
NEW YORK (Reuters Health) - Heart disease is the single biggest killer of women and inactivity is the biggest contributor to heart disease for all but the youngest ones, according to Australian researchers.
They parsed the sources of cardiovascular risk among women of all ages in Australia and found smoking, obesity and high blood pressure are near the top of the list. But if all sedentary women ramped up their activity levels, the largest number of deaths would be averted.
“Understanding the risks associated with the development of serious health problems can inform more targeted intervention strategies,” said the study’s lead author Wendy Brown, an exercise physiologist at the University of Queensland.
Heart disease is the leading killer of women in the United States, where an estimated one in four women dies of the disease, and similar statistics prevail in Australia.
To measure the importance of various risk factors for heart disease, Brown and her team analyzed data from a long-term study that followed Australian women from 1996 to 2011, surveying them about their lifestyle and health every three years.
The roughly 30,000 participants ranged from 22 to 90 years old and fell into three groups born from 1973 to 1978, 1946 to 1951 and 1921 to 1926.
The researchers calculated for each group the extent to which the presence of heart disease could be attributed to body mass index (BMI, a measure of weight relative to height), physical inactivity, high blood pressure or smoking.
Overall, being sedentary was the greatest contributor to heart disease among women over age 30, including women as old as 90.
Smoking was the biggest culprit among women between the ages of 22 and 27. In that group, where heart disease is rare, smoking accounted for about 60 percent of it, according to the results published in the British Journal of Sports Medicine.
High blood pressure was least common among the youngest women, and high BMI (overweight or obese) was most common in the middle age group.
Inactivity was widespread, with 65 percent of women 73 to 78 years old and 81 percent of those 85 to 90 getting little or no physical activity.
Based on rates of death from heart disease in Australia, the researchers calculated that if all the women represented by the study population could do about 1 hour of moderately intense activity a day, some 2,612 deaths would be avoided.
That’s more Australian women than are killed in road accidents each year, they point out.
“Physical activity hasn’t been studied as well; the other risk factors (like body mass index) have been more targeted in the past,” said Nisha Parikh, a cardiologist at the University of California, San Francisco, who was not involved in the study.
“The nice thing is all these things track together,” Parikh told Reuters Health. “If you increase your physical activity, you generally lower body mass index, and you’re also going to have an impact on lowering blood pressure,” she said.
The study shows the importance of boosting activity levels at all ages, she added, and although that can be difficult, there are many simple ways for busy people to get in a few extra steps each day, like taking the stairs and parking a little farther away from their destination.
“Those kinds of things increase physical activity in a way that doesn’t impact the rest of the things busy people have going on,” Parikh said.
SOURCE: bit.ly/1jEjPrA British Journal of Sports Medicine, online May 8, 2014.