NEW YORK (Reuters Health) - A new study shows heart attacks and strokes are more common in women infected with human papillomavirus, or HPV.
The research only included a small number of women with heart disease, and it doesn't prove that the sexually transmitted infection is to blame. In fact, it's still unknown whether the women already had the virus before they suffered heart attacks and strokes.
Previous studies have suggested an increased risk of heart disease in people with certain infections, including HIV, hepatitis C and one strain of Chlamydia -- but also haven't been able to prove cause-and-effect.
"It is unclear what is the underlying mechanism for such risk, though the infection itself, (the) body's reaction to infection or a general milieu of inflammation may account for a part of the risk," said Dr. Adeel Butt, from the University of Pittsburgh School of Medicine, in an email to Reuters Health. He was not involved in the new work.
The report includes data from a national health survey that was analyzed by Dr. Hsu-Ko Kuo and Dr. Ken Fujise from the University of Texas Medical Branch in Galveston.
Close to 2,500 women between age 20 and 59 took vaginal swabs for HPV testing and told researchers whether or not they had ever been diagnosed with a stroke or heart attack.
About 47 percent of the women tested positive for HPV. The infections were evenly split between strains that can cause cervical cancer and non-cancer strains.
Sixty women reported a history of heart disease -- 39 who also tested positive for HPV, and 21 with no HPV. Women with HPV were more than twice as likely to say they'd had a stroke or heart attack, once researchers accounted for other heart risks including smoking, drinking and high blood pressure.
Breaking down the data further showed that it was only the cancer-causing HPV strains that were linked to an increased risk of cardiovascular disease. The researchers couldn't distinguish between chronic and short-lasting infections.
Because women were only tested and surveyed at a single time point, Kuo and Fujise also couldn't be certain if they got infected with HPV before or after suffering heart attacks and strokes.
In an editorial published with the study, Dr. Joseph Muhlestein from Intermountain Medical Center in Murray, Utah, pointed out that most women who get cardiovascular disease are over 60, so it's unclear how the findings in this younger group apply to them.
He added that larger studies that follow women over time are needed to clarify the link between HPV and heart disease.
So far, whether chronic infections play a role in heart disease remains "neither proven nor disproven," Muhlestein wrote in the Journal of the American College of Cardiology.
"Those who have HPV infections do not have to panic at all," Fujise told Reuters Health in a phone interview.
"More extensive vaccination may potentially prevent ... the incidence of coronary heart disease, heart attack and stroke, but this needs to be tested" in a bigger trial, he added.
The American College of Obstetricians and Gynecologists advises girls and women age nine to 26 to get the HPV vaccine, with the first vaccination typically starting at 11 or 12, to prevent future cervical cancers.
"Women should be evaluated for HPV vaccination whether or not HPV association with heart disease is proven," said Butt.
On Tuesday, U.S. vaccine advisers recommended that 11- and 12-year-old boys should be routinely vaccinated against HPV as well.
SOURCE: bit.ly/v3IS7l Journal of the American College of Cardiology, online October 24, 2011.