Oct. 24, 2011 -- It's well known that several types of human papillomavirus (HPV) cause most cases of cervical cancer. Now new research suggests that some of these same types of HPV may also increase a woman's likelihood of having a heart attack and/or stroke -- even without any other risk factors.
Two HPV vaccines are now approved by the FDA. Both of these vaccines are recommended to prevent cervical cancers. They are now on the CDC's childhood routine vaccination schedule for girls starting at age 9.
The findings are published in the Journal of the American College of Cardiology.
HPV and Heart Attack Risk
The study included information on 2,500 women aged 20 to 59. Of these, 44.6% tested positive for HPV, and 23.2% tested positive for the HPV strains that are linked to cervical cancer.
Women with HPV infection are 2.3 times more likely to have a heart attack or stroke as women who are not infected with these strains of HPV, says study researcher Hsu-Ko Kuo, MD, MPH, of the University of Texas Medical Branch in Galveston.
"For every 55 females with HPV, there will be one heart attack or stroke," he says. This was true even in the absence of other known risk factors for heart attack or stroke such as high blood pressure, high cholesterol, diabetes, and high body mass index.
Exactly how -- or even if -- HPV increases a woman's risk for heart attack and stroke is not known. It may affect certain genes that help protect the arteries from atherosclerosis (hardening of the arteries). This process sets the stage for heart attack and stroke.
The next step is to try to understand this further, he says. After that, researchers want to examine the link in older women and men to see if the findings still hold. Then "we hope to look at the effects of vaccine to see if it can protect females from heart disease," he says.
Can a Shot Prevent Heart Disease?
Suzanne Steinbaum, DO, is "floored" by the new findings. She is the director of women and heart disease at Lenox Hill Hospital in New York City. "Those who had the cancer-causing HPV strain had an increased risk of cardiovascular disease and stroke, without any of the other traditional risk factors being present."
The study "sheds a new light on the assessment and risk factor analysis of heart disease in women, many of whom have HPV, and lends a new direction into the understanding of who is at risk for heart disease and therefore another means for us to prevent it," she says.
Nieca Goldberg, MD, medical director of the Joan H. Tisch Center for Women's Health and the Women's Heart Program at New York University Langone Medical Center in New York City, urges caution in interpreting the new findings.
"It would be groundbreaking, but we are so early on in the process," she says.
"If this is eventually proven to be a real risk for heart disease, it will be a way to identify younger women who are at risk," she says.
But it is a big leap to say that the HPV shot could protect women from heart attack and strokes. "HPV causes cervical cancer. In terms of cardiovascular disease risk, there may be a connection, but we are not there yet," she says.
There are things that women can do today that we know will lower their risk for heart attack or stroke, she says. These include quitting smoking, making sure their blood pressure, cholesterol levels, and body weight are within the normal range, and engaging in regular physical activity.
"We can't let people forget about the other risk factors," she says.