Jackson Heart, tobacco study link smoking, peripheral artery disease

Published on Monday, January 28, 2019

By: Karen Bascom

African-Americans who smoke cigarettes are more likely than those who don’t smoke to develop peripheral artery disease, or PAD, according to new research from the University of Mississippi Medical Center and data from the Jackson Heart Study.

Published in the Journal of the American Heart Association January 23, the study shows that the more cigarettes smoked daily, the more likely a person was to develop PAD.

“Peripheral artery disease is a major disease burden in the African-American population,” said Dr. Donald “Trey” Clark III, assistant professor of medicine and lead author of the study. “Establishing a clear association between smoking and peripheral artery disease in African Americans can help guide our efforts to lower risk and improve health in this population.”

PAD is a narrowing of arteries that don’t flow directly to the heart. Instead, they move blood to arms and legs, as well as vital organs like the brain and kidney. If this blood flow is reduced, stroke, kidney failure, erectile dysfunction, pain in the legs when walking and even loss of limbs can occur. PAD is associated with hypertension, diabetes and obesity, all of which increase the risk for cardiovascular disease.

Cigarette smoking is a known PAD risk factor. According to Centers for Disease Control and Prevention data, African-Americans and non-Hispanic whites have comparable rates of current cigarette use, at 16.5% and 16.6%, respectively. However, African-Americans have more than twice the rate of PAD.

The Jackson Heart Study is the largest single-site cohort study of cardiovascular health and disease in African-Americans. It is a 20-year collaboration between UMMC, Jackson State University, Tougaloo College and 5,300 residents of Hinds, Madison and Rankin counties. The Mississippi State Department of Health joined the study during its August 2018 renewal. The National Heart, Lung, and Blood Institute and National Institute on Minority Health and Health Disparities fund the study.

Because of its size and participant population, “The Jackson Heart Study is in a unique position to evaluate the extent to which variations in prevalence of modifiable cardiovascular disease risk factors such as tobacco and cigarette use among population subgroups contribute to health disparities,” said Dr. Adolfo Correa, director of the JHS.

Among the JHS participants included in this study, 68 percent have never smoked, 19 percent are past smokers and 13 percent are current smokers.

The researchers determined if individuals had PAD by measuring the ankle-brachial index, ABI for short, which compares blood pressure in the arteries of the extremities. A low ABI is a sign of PAD. They also used computer tomography scanning to look for calcium and plaque build-up in blood vessels.

Current smokers were twice as likely as non-smokers to have subclinical PAD and were eight times more likely to have calcium build-up in the aorta, the body’s main artery. In addition, participants who smoked 20 or more cigarettes daily had higher odds of PAD compared than those who smoked fewer than 20 cigarettes daily.

“These findings demonstrate that smoking is associated with PAD in a dose-dependent manner,” Clark said. “This is particularly important in the African-American community and supports the evaluation of smoking-cessation efforts to reduce the impact of PAD in this population.”

This study is also part of the American Heart Association’s Tobacco Regulation and Addiction Center, also called A-TRAC, funded by the Food and Drug Administration and the National Institutes of Health. The initiative’s goal is to conduct research on the cardiovascular effects of tobacco in order to inform the FDA regulatory policy, to learn more about the attitudes and behaviors associated with tobacco use and to shape effective communication about the health effects of tobacco.

In October 2018, A-TRAC’s funding was renewed for five years. The team includes several UMMC investigators, including Dr. Michael Hall, associate professor of medicine.

“Historically, marketing of tobacco products has been more aggressive in African-Americans,” said Hall, corresponding author for the study. “This is despite the abundance of evidence that African-Americans seem to be more affected by the adverse health effects of tobacco products, such as vascular disease, kidney disease, and heart disease, compared to whites.”

“Our findings add to the mountain of evidence of the negative effects of smoking and highlight the importance of smoking cessation, as well as prevention of smoking initiation,” Clark said.

UMMC-affiliated authors include Dr. Javed Butler, professor and chair of medicine and Patrick Lehan Chair of Cardiovascular Research; Dr. Ken Butler, professor of medicine; Dr. Loretta Cain, assistant professor of data science; Dr. Michael Hall; associate professor of medicine; and Dr. Daisuke Kamimura, faculty clinician-scientist in medicine. Dr. Wendy White, principal investigator of the JHS undergraduate center at Tougaloo College is also a co-author. Other authors represent Johns Hopkins University, University of Louisville, Duke University, Vanderbilt University, and Boston University.

Ready to quit using tobacco? The UMMC ACT Center’s team of clinicians helps patients through counseling- and medication-based approaches. For more information, visit www.act2quit.org or call 601-815-1180.