番茄社区

MILAN -- Nicotine exposure from vaping was associated with a transient, but potentially harmful, increase in arterial stiffness, according to researchers here.

The study included 15 young adults (average age of 26) with no history of electronic cigarette use who identified themselves as seldom smokers, meaning that they smoked no more than 10 cigarettes a month. They vaped e-cigarettes with nicotine for 30 minutes on one study day and non-nicotine containing e-cigarettes for the same length of time on another study day in a controlled setting, explained Magnus Lundback, MD, PhD, of the Karolinska Institute in Stockholm, and colleagues.

During the first 30 minutes after smoking e-cigarettes containing nicotine, a three-fold increase in arterial stiffness was observed, as well as increases in blood pressure and heart rate. These effects were not seen following the non-nicotine vaping session, they reported at the (ERS) International Congress.

These early findings may have important implication for the use of e-cigarettes in smoking cessation, the authors noted. In addition it is the first clinical trial to link e-cigarette exposure to arterial stiffening in humans, they stated.

Lundback told 番茄社区 that even though the study was small and the results should be considered preliminary, they raise concerns about possible cardiovascular risks associated with e-cigarette use.

"There are thousands of toxins in conventional cigarettes, and the thinking has been that they, and not nicotine, are responsible for these cardiovascular effects," he said. "But this study suggests that that might not be the case. It may be that continuous, repeated exposure to e-cigarettes may chronically alter vascular stiffness and increase the risk for cardiovascular events in the future."

While the effects on blood pressure, heart rate, and arterial stiffness seen in the study lasted no more than 30 minutes, they mimicked the temporary effects on arterial stiffness seen in cigarette smokers.

Lundback noted that chronic exposure to both active and passive conventional cigarette smoke is known to permanently increase arterial stiffness over time.

His group took measurements of blood pressure, heart, and arterial stiffness at three time points during each vaping session: during the first 30 minutes following exposure and at 2 and 4 hours post-exposure.

Because exposure to non-nicotine e-cigarettes was not associated with an increase in these cardiovascular risk factors, the immediate increase was most likely attributable to nicotine, Lundback said.

"Our results underline the necessity of maintaining a critical and cautious attitude towards e-cigarettes, especially for healthcare professionals," he said.

Lundback told 番茄社区 that efforts to legitimize e-cigarettes as potential alternatives to readily available nicotine replacement therapies (NRTs) may expose smokers who want to quit to unnecessary risk.

"These NRTs work well," he said, adding that the long-term risks of e-cigarettes are not known. "We should be very cautious in promoting these products for smoking cessation."

Francesco Blasi, MD, PhD, of the University of Milan and ERS past president, agreed that because the long-term effects of using e-cigarettes containing nicotine are not known, promoting their use for smoking cessation is problematic.

"The problem is, we haven't had randomized, clinical trials that are big enough to understand the efficacy and safety of these products for this use," said Blasi, who was not involved in the research. "And the smaller studies have shown mixed results."

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