The prevalence of asymptomatic peripheral artery disease appears to be steadily increasing among American adults, according to a presentation at the annual meeting of the American Heart Association.

“We were interested in seeing if the prevalence of peripheral artery disease in the general U.S. population is increasing, specifically among people who do not have known coronary artery disease,” said Andrew D. Sumner, MD, lead author of the study and medical director of the Heart Station and Cardiac Prevention at Lehigh Valley Hospital in Allentown, PA.

Researchers hypothesized that the prevalence of asymptomatic peripheral disease is increasing and that the increase is associated with a rise in the prevalence of other common cardiovascular risk factors, including diabetes, smoking, obesity and hypertension.

Sumner and colleagues analyzed data from three successive National Health and Nutrition Examination Surveys (NHANES), conducted in two-year increments between 1999 and 2004, finding a case of peripheral artery disease by identifying people with an ankle-brachial index of less than 0.9.

Sumner explained, “The ankle-brachial index measures the ratio of the blood pressure in the arms and legs, and if it is less than 0.9, people by definition have peripheral artier disease.”

The researchers then examined the prevalence of associated cardiac risk factors of obesity, diabetes, hypertension and smoking in 5,376 participants, age 40 years and older with no prior history of cardiovascular disease.

They found that prevalence among asymptomatic adults 40 years and older significantly increased from 3.7 percent in the 1999-2000 survey to 4.2 percent in the 2001-02 survey and 4.6 percent in the 2003-04 survey.

“Peripheral artery disease prevalence was highest among those age 70 and older,” Sumner said. “But there also was an increase in the prevalence in each adult age group, including 40 to 49, 50 to 69 and greater than 70 years.”

The authors said prevalence of obesity, diabetes, hypertension and smoking also increased over these three surveys.

“Peripheral artery disease is affecting more people in the United States and will continue to do so because the prevalence of this problem increases as we get older, and we have an aging population,” Sumner said. “And this increase is associated with an increase in common cardiac risk factors.”