The study results "demonstrate that there is an association between depression and PAD," says researcher S. Marlene Grenon, MD. She is an assistant professor of surgery at the University of California, San Francisco. "We know that if you have depression, your risk for PAD is likely related to poor health behaviors like smoking and physical inactivity."
The findings were presented at the American Heart Association's Arteriosclerosis, Thrombosis, and Vascular Biology 2012 Scientific Sessions in Chicago.
People who were depressed were more likely to be younger and female. They were also more likely to have lower HDL ("good" cholesterol), high levels of C-reactive protein, which is a sign of inflammation in the body, and a history of heart attack, heart failure, or diabetes. They also tended to smoke and be physically inactive, and were less inclined to take their medications as directed.
Seven percent of depressed people and 5% of those without depression had a PAD-related event during the study period. These included surgery to open blocked leg arteries or other treatments.
What Is PAD?
PAD occurs when arteries away from the heart become narrowed and blocked. The leg and pelvis arteries are most commonly affected. PAD involving the leg arteries can cause pain while walking, climbing stairs, or exercising. This pain usually stops during rest.
PAD treatment includes lifestyle changes -- such as eating a healthy diet, quitting smoking, and getting more exercise -- that are aimed at reducing these risks. Medications to treat conditions that increase risk for PAD and/or surgery to open blocked leg arteries are also options.
"If people have pain with walking or lesions on their feet, they should be evaluated by a doctor to see if it is PAD," Grenon says. "If they do have PAD, they should make sure that they get proper treatment."
Is depression a red flag for PAD? "I don't think we can say that yet, but we need to look at other risk factors in patients with depression," she says. "People who have depression are at increased risk for heart disease and PAD in the future, but at present, they are more at risk of having certain poor health behaviors that could increase their risk of heart disease."
What Comes First?
Is depression the chicken or the egg? Vivienne Halpern, MD, is not sure. She is the chief of vascular surgery and a clinical associate professor of surgery at University of Arizona College of Medicine in Phoenix. "It has also been shown in prior studies that after PAD develops, there is an increasing risk of depression due to ... the feelings of endless problems and not feeling well that don't go away," she says in an email. "This is understandable as many of these diseases, including PAD, greatly alter what one is able to do and how one feels."
Treating the depression may help improve PAD. "It aids in having them participate in their care, helps them achieve better activity levels and avoid destructive habits," she says.
Regardless of which condition comes first, Alan Manevitz, MD, says that addressing the depression is important. He is a clinical psychiatrist at Lenox Hill Hospital in New York.
"Depression and heart disease are linked, and together they make for a more a difficult prognosis," he says.
Treating depression often has positive spillover benefits on other conditions.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.