研究表明，只使用一次电子烟就能改变血管

A new study is the latest to show changes in cardiovascular function after vaping e-liquids, though in this case, those liquids didn't even contain nicotine.

最新的一项研究表明，电子烟会改变心血管功能，不过在这种情况下，电子烟甚至不含尼古丁。

The study, published Tuesday in the journal Radiology, concluded that vaping temporarily impacts blood vessel function in healthy people. Using MRI scans, it found, for example, changes in blood flow within the femoral artery in the leg after just one use. The researchers couldn't determine which chemical might be responsible for the changes they observed.

周二发表在《放射学》杂志上的这项研究得出结论，蒸汽会暂时影响健康人的血管功能。例如，通过核磁共振成像扫描，研究人员发现，仅仅使用一次，腿部股动脉内的血流就发生了变化。研究人员无法确定是哪种化学物质导致了他们观察到的这些变化。

"After a few minutes, everything normalizes. One could say, big deal, nothing happens," said study author Felix W. Wehrli, professor of radiologic science and biophysics at the University of Pennsylvania's Perelman School of Medicine.

几分钟后，一切都恢复正常。这项研究的作者、宾夕法尼亚大学佩雷尔曼医学院放射科学和生物物理学教授费利克斯·w·韦赫里说:“人们可能会说，没什么大不了的，什么也没发生。”

"But if someone vapes regularly," Wehrli continued, there's a possibility that, over time, things might not go back to normal as readily. The changes his team measured in 31 people, who had never vaped or smoked, reflect the same processes," including atherosclerosis. But that takes years to develop, he added.

“但如果一个人经常吸电子烟，”韦赫里继续说，随着时间的推移，事情可能不会那么容易回到正常状态。他的团队对31名从未吸过电子烟或从未吸过卷烟的人进行了测量，发现有同样的过程，”包括动脉粥样硬化。但这需要数年的时间来发展，他补充说。

The study is the most recent addition to a proliferation of research aiming to measure the impact of e-cigarettes on the heart, blood vessels, lungs and brain. But experts say the research remains in its early stages, often taking place in the lab or in animals.

这项研究是众多旨在测量电子烟对心脏、血管、肺和大脑影响的研究的最新进展。但专家表示，这项研究仍处于早期阶段，通常在实验室或动物身上进行。

A study in May, for example, found evidence that e-cigarette flavors had toxic effects -- including poorer cell survival and signs of increased inflammation -- on a type of cardiovascular cell in the lab.

例如，今年5月的一项研究发现，有证据表明，电子烟的味道对实验室里的一种心血管细胞有毒性影响，包括降低细胞存活率和增加炎症的迹象。

"The use of e-cigarettes is increasing and the data demonstrating potential harm ... is also growing," doctors from the University of Massachusetts Medical School said in a commentary published alongside the May study. "In addition to harm from the nicotine, the additives are a potential source of adverse vascular health and one that is being disproportionately placed on the young."

“电子烟的使用正在增加，数据显示了潜在的危害……麻省大学医学院的医生们在5月份发表的一篇评论中说。“除了尼古丁的危害之外，这些添加剂还会对血管健康造成潜在的不利影响，而且对年轻人的影响尤为严重。”

While experts have long suspected that vaping poses fewer health risks than smoking cigarettes, the doctors wrote that "little is known about the potential toxicology" of flavorings, particles, heavy metals and other components used in e-cigarettes.

长期以来，专家们一直怀疑电子烟对健康的危害小于吸烟，但医生们写道，电子烟中使用的香料、微粒、重金属和其他成分的“潜在毒理学知识知之甚少”。