Vaping impacts blood vessels, even without nicotine

Healthy young people show signs of impaired blood vessel function after just a few puffs of an electronic cigarette, even without nicotine, new research shows.

"We essentially found that using e-cigarettes is not equivalent to inhaling water vapour; in fact, it can exert acute, detrimental effects on (blood vessels) even when the liquid does not contain nicotine," Dr. Alessandra Caporale of the University of Pennsylvania Perelman School of Medicine in Philadelphia, the study's first author, told Reuters Health in an email.

Evidence is mounting that vaping, sometimes touted as a safer alternative to smoking, is not risk-free, Dr. Caporale and her colleagues note in Radiology. In a previous study, they found that vaping nicotine-free e-cigarettes increased signs of inflammation and a form of tissue damage known as oxidative stress, which returned to normal levels in one to three hours.

Big US tobacco companies are all developing e-cigarettes. The battery-powered devices feature a glowing tip and a heating element that turns liquid nicotine and flavorings into a cloud of vapour that users inhale.

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In the new study, the authors used magnetic resonance imaging (MRI) to take several measurements of blood vessel function in 31 healthy adults who had never smoked, before and after they took 16 three-second puffs of an e-cigarette containing propylene glycol, glycerol and flavoring but no nicotine.

After vaping, study participants showed several changes indicating that "vascular reactivity," which is the ability of healthy blood vessels to widen when necessary, was "considerably and significantly impaired," Dr. Caporale noted.

These changes were temporary, but if repeated over a long period of time could cause inflammation and deterioration of blood vessel health, the researcher added. "We are far from suggesting that a single episode of vaping translates immediately into atherosclerosis."

With funding from the National Heart, Lung, and Blood Institute, which also supported the current research, Dr. Caporale and her team are planning a study that will look at inflammation, oxidative stress and circulatory changes in e-cigarette users, cigarette smokers and non-smokers over time.

Dr. Irfan Rahman, a professor at the University of Rochester Medical Center who researches the effect of e-cigarettes on health, reviewed the study for Reuters Health. "The study is interesting and has some insights into long-term consequences of electronic cigarette vapours in cardioneurovascular disorders," he told Reuters Health in a telephone interview.

But the findings don't confirm an association and shouldn't be interpreted to mean that e-cigarette users will develop these health problems, he added.