婦女感染HPV會增加得心髒病的危險

美國研究人員已找到人類乳突病毒（HPV）感染與心髒疾病間的關聯。這項研究的受試婦女皆無其他風險因子，報告結果在昨天發表，為這類型研究之首。

盡管這項研究尚屬早期階段，專家表示若經證實，將可為對抗心髒疾病提供新方法。心髒疾病為大部分國家的婦女頭號殺手。

德克薩斯州大學醫學分校（University of Texas Medical Branch）心髒內科（Division of Cardiology）主任藤瀨（Ken Fujise）說：〝近20%心血管疾病患者沒有顯現任何風險因子，顯示‘非傳統’成因可能隱含在內。〞

藤瀨說：〝HPV似乎是女性1項危險因子。〞

研究人員會想到調查HPV為潛在心髒疾病風險，是因為其抑製p53及pRb兩種腫瘤抑製基因、引發癌症。p53是調節動脈粥狀硬化過程的關鍵基因；pRb則是調節細胞周期的重要因素。

同樣來自UTMB的研究共同作者郭緒格（Hsu-Ko Kuo，譯音）表示，盡管研究人員尚未證實HPV與心髒疾病的關聯性，但的確發現〝致癌HPV類型與心髒疾病的強烈相關〞。研究對象為2500名20至59歲女性。

研究將刊於11月1日號的〝美國心髒病學會期刊〞（Journal of the American College of Cardiology）。

HPV是最普遍的性傳染病，類型逾40種，部分可導致子宮頸癌或尖形濕疣，但大多數時候HPV不會出現任何症狀。

Women who carry the human papillomavirus (HPV) have an increased risk of heart disease, a new study finds.

Women who tested positive for any of the 37 strains of the virus the researchers tested for were 2.3 times more likely to also have had either a heart attack or stroke than women who tested negative, the study found. And women who tested positive for either of the two strains associated with cervical cancer had 2.86 times the risk of heart attack or stroke, according to the study.

As such, the study suggests that "the HPV vaccine may also help prevent heart disease," said lead author Dr. Ken Fujise, director of cardiology at the University of Texas Medical Branch at Galveston.

Nearly 20 percent of people who develop heart disease do not have any known risk factors, such as smoking or high blood pressure, which indicates that other "nontraditional" causes may be involved. "HPV appears to be one such factor among women," Fujise said.

Still, women with HPV should not worry because "this is very first study to link HPV with [heart disease],” Fujise said. Longitudinal studies, which follow patients over time, are needed to confirm the link between HPV and heart disease. "However, our data suggests those patients should be followed more closely by their doctors — if [they] have chest pain, take it very seriously," he said.

The study will be published on Nov. 1 in the Journal of the American College of Cardiology.

HPV and heart disease

The study included nearly 2,500 women between the ages of 20 and 59; the researchers gathered data from the National Health and Nutrition Examination Survey, conducted by the Centers for Disease Control and Prevention between 2003 and 2006.

Among the study participants, 44.6 percent tested positive for HPV, including 23.2 percent who had the cancer-causing strains of the virus. Other studies have found that the virus is found in between 20 percent and 45 percent of people in the general population, Fujise said.

Of the 60 women in the study who reported they'd had either a heart attack or stroke, 39 tested positive for any HPV strain, and 21 tested negative.

"I thought there would be a weak link between HPV and cardiovascular disease, but I didn't expect [the risk] to be 2.3 times as high," Fujise said.

The study showed that for every 55 women with HPV, one woman is likely to have a heart attack or stroke because of the virus, rather than because of other risk factors, Fujise said.

Every year, 510,000 U.S. women have heart attacks, according to the American Heart Association. If the study's findings hold up in larger studies, Fujise calculated that would mean that 4,321 of these women are having heart attacks due to HPV, rather than other risk factors; and 1,618 women die yearly from these HPV-related heart attacks.

How a virus might cause a heart attack
 
The researchers said the link might be due to the virus's ability to silence two genes known to play roles in the health of blood vessels. The two genes, called p53 and retinoblastoma protein, both work to suppress the growth of tumors. Atherosclerosis, which is the thickening of artery walls, is also regulated by p53, while the retinoblastoma gene regulates the growth of smooth muscle cells that line blood vessels, and so could impact blood flow.

"We didn't study males, but men can be infected with HPV. Our next hypothesis is that maybe male HPV vaccinations would protect men from heart attacks and stroke," Fujise said.

If researchers find the exact mechanism by which HPV causes heart attacks and stroke, they could look for a drug that could treat people infected with the virus to lower their risk, he said.

Pass it on: Women with HPV may have a higher risk of heart disease.