Though obesity and smoking are widely touted as two of the largest risk factors for cardiovascular disease, according to a new study the two still fall below one measure as the greatest threat to women over the age of 30: physical inactivity.

Lack of exercise is quickly becoming one of the greatest afflictions for middle-aged people, whose day jobs require less-demanding physical labor and whose nights are often filled with busy family obligations. Making the time to stay active is effortful, so many people shirk it altogether. Unfortunately, the present researchers find, our health is paying a major price.

Researchers from the University of Queensland looked at data among 32,154 participants in the Australian Longitudinal Study on Women's Health, which has been tracking the long term health of women born in 1921-26, 1946-51, and 1973-78, since 1996. Specifically, they scanned for four risk factors: excess weight (high BMI), smoking, high blood pressure, and physical inactivity. To understand the relationship between health and behavior, they relied on the population attributable risk (PAR) — a mathematical formula used to describe how much of a disease would disappear if the people in a population were no longer exposed to a risk factor.

Overall, the team found smoking rates fell from 28 percent in women age 22 to 27 to five percent in 73- to 78-year-olds. Meanwhile, the other three factors rose in prevalence. Obesity increased from ages 22 to 64, but then declined over time thereafter. High blood pressure and inactivity increased steadily from 22 to 90. With a PAR of 59 percent, smoking posed the greatest risk for heart disease before age 30. But after analyzing the specific PAR of each factor after age 30, inactivity stood out as the greatest risk factor until people’s late eighties.

"Our data suggest that national programmes for the promotion and maintenance of physical activity, across the adult lifespan, but especially in young adulthood, deserve to be a much higher public health priority for women than they are now,” the researchers conclude.

Prior research implicates several other risk factors as possible contributors of heart disease, which currently stands as the leading cause of death in many developed nations. These include: high-salt diets, poor oral health, celiac disease, postpartum obesity, and simply poor genetics. The present study shines an important light on the overall benefits of exercise, which, in the U.S., health officials recommend people get at least 150 minutes of each week.

Moderate forms of activity include brisk walking or light cycling, while more vigorous forms include jogging, running, or swimming. If every woman between the ages of 30 and 90 were able to stick to this weekly exercise quota, the researchers estimate that the lives of more than 2,000 middle-aged and elderly women could be saved each year in Australia alone.

 

Source: Brown W, Pavey T, Bauman A. Comparing population attributable risks for heart disease across the adult lifespan in women. British Journal of Sports Medicine. 2014.