A virus responsible for the majority of cervical cancers might also raise a woman's risk of heart attack and stroke, according to researchers who suggest HPV might underlie some cardiovascular disease in people who do not have such traditional risk factors as obesity, diabetes or smoking.
If additional research supports an association between cancer-linked strains of human papillomavirus (HPV) and clogged arteries, doctors might want to monitor HPV-infected women for heart disease, the researchers suggested. In addition, they proposed that HPV vaccines, now used to protect young women and men against cervical and anal cancers, might offer "additional benefit in cardiovascular health."
Writing in the Nov. 1 issue of the Journal of the American College of Cardiology, Dr. Keniche Fujise, director of cardiology at the University of Texas Medical Branch in Galveston, and Dr. Hsu-Ko Kuo, a UTMB internist, said they were the first to link HPV and cardiovascular disease. They said their work didn't establish that HPV infection caused heart attacks and strokes, but instead provided a path for further investigation. They also said that because their findings were limited to women, that left open the question of whether they could apply to men too.
HPV is among the most common sexually transmitted infections in the United States. HPV strains are present in more than a quarter of the population, according to federal statistics. Most HPV infections are transient and cause no major health problems, while others produce genital warts, which require medical treatment to avoid further spread. Two strains, HPV 16 and HPV 18, are responsible for 70 percent of cervical cancer, while HPV 16 accounts for about 85 percent of anal cancers and many tongue and throat cancers.
The authors set about studying the potential role of HPV in heart disease because of previous evidence that some proteins present in cancer-causing HPV strains disarm an important tumor-suppressing gene called p53, which also plays a role in clogging of the arteries, called atherosclerosis. Furthermore, patients in whom the p53 gene is disabled or inactivated are more prone to reclogging of their arteries after blockages have been surgically scraped away. So Fujise and Kuo reviewed HPV and heart disease data from an ethnically and geographically diverse sample of 2,450 women, ages 20 to 59, who participated in the National Health and Nutrition Examination Survey in 2003-2006, a large federally funded study.
They homed in on the 60 survey respondents told by health professionals that they'd suffered a stroke or heart attack. The doctors reviewed laboratory analyses of HPV from vaginal swabs each of the women provided, for the presence of 13 types of HPV defined as either cancer-causing or cancer-associated. Samples from nearly a quarter of the women tested positive for cancer-associated HPV. Women with those strains tended to be younger and have a greater prevalence of cardiovascular disease than the uninfected women.
In an accompanying editorial, Dr. Joseph B. Muhlestein, a cardiologist at the University of Utah in Salt Lake City, wrote that investigators for years have been pursuing the possibility that cardiovascular disease may be rooted in infection. In 1996, Muhlestein discovered that a large proportion of patients undergoing coronary bypass surgery were infected with Chlamydia pneumoniae. He's been among investigators who have failed to prove that antibiotic treatment of C. pneumoniae prevents strokes and heart attacks. Nevertheless, he expressed the hope that "in the end, the infectious hypothesis of atherosclerosis may still pan out."