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Human Papillomavirus Linked to Heart Disease
Human papillomavirus (HPV) is the most common sexually transmitted infection in the U.S. New research suggests it may also raise women's risk of contracting heart disease.
Women who tested positive for HPV DNA were between two and three times as likely as uninfected women to suffer a heart attack or stroke. The study does not show that the infection caused heart disease. It does suggest that the two conditions are linked.
This raises the possibility that the HPV vaccine (there are two) could help prevent heart disease and suggests that doctors should monitor patients with known HPV infections for indications of developing heart disease.
Scientists estimate that half of sexually active men and women have been infected with HPV and that 80 percent of women have had it by age 50. But in most people, the body's immune system successfully fights off the virus and it causes no health problems. The Centers for Disease Control and Prevention (CDC) estimates that 70 percent of new HPV infections go away within one year, and 91 percent are gone within two years.
There are more than 100 strains of HPV. When certain strains stay active in the body for a long time, they can cause cancer, particularly cervical cancer.
To test whether HPV was associated with heart disease, researchers at the University of Texas Medical Branch at Galveston examined data from 2,450 women, ages 20 to 59, who took part in a national health survey from 2003 to 2006 (NHANES). Infection with HPV was determined by DNA testing of vaginal swabs. Heart disease was any self-reported heart attack or stroke.
Nearly half of the women (1,141) tested positive for HPV. Sixty women reported heart disease, 39 of whom also tested positive for HPV. When the researchers analyzed the data and adjusted for other heart risks like smoking, blood pressure and weight, they found that women with HPV were 2.3 times as likely as those without the virus to have heart disease. The risk was even higher, 2.9 times that of uninfected women, in those who had HPV strains known to cause cancer.
Even if further research confirms the connection, most people who contract HPV would not be at special risk for heart disease. If the link is real, heart disease, like cancer, would be likely to develop only in people with lingering HPV infection.
Cancer causing strains of HPV are known to inactivate a protein called p53 that helps prevent cells from turning cancerous. Inactivation of p53 may also cause inflammation and thickening in the walls of arteries. The study results raise the possibility that a drug that protects p53 from degradation could help prevent heart disease in people who are infected with HPV.
The study results are only preliminary. The association between HPV and heart disease does not even tell which condition came first. It's possible that heart disease could have made the women more vulnerable to HPV. Or some other unknown factor could have predisposed the women to both HPV and heart disease. It will take more rigorous studies to prove that infection with HPV actually raises the risk of contracting heart disease.
Men can get HPV infections, too. But there's no reliable way of collecting a suitable genital sample for testing from men, so there's no approved HPV test for them. That's why most of the known information on HPV infections is from women.
An article detailing the study appears in the November 1, 2011 issue of the Journal of the American College of Cardiology. A video of the one of the authors discussing the study appears here.
November 2, 2011