By Marilynn Larkin
NEW YORK (Reuters Health) - 15/5/2019
Short-term respiratory responses to use of e-cigarettes and tobacco cigarettes are similar, researchers say.
Dr. Grzegorz Brozek of the Medical University of Silesia in Katowice, Poland and colleagues assessed acute respiratory responses to e-cigarettes in individuals who used e-cigarettes exclusively (E group) and dual users of tobacco and e-cigarettes (T/E group), and compared the effects with tobacco users only (T group) and controls. Their study was a continuation of a questionnaire survey conducted as part of the multicenter, international project YoUng People E-Smoking Study.
Thirty participants were included in each group. Participants had a mean age of about 23 and about 40% overall were women.
As reported online May 2 in Scientific Reports, the researchers measured spirometric status, oxygen saturation, exhaled nitric oxide (FeNO), exhaled carbon monoxide and exhaled breath temperature before the use of an e-cigarette (E and E/T groups) or tobacco cigarette, as well as one minute and 30 minutes afterward. Controls used an e-cigarette without e-liquid.
Lower baseline FeNO values were found in the T (15.4 ppb) and T/E (15.0 ppb) groups than in controls (19.6 ppb). Following exposure, the T and T/E groups also had significant decreases in peak expiratory flow (PEF) and maximal expiratory flow at 75% (MEF75) compared with controls.
One minute after exposure, mean FeNO values decreased in the T group by 2.1 ppb, by 1.5 ppb in the E group and by 2.2 ppb in the T/E group. However, by 30 minutes post-exposure, FeNO values had increased, reaching a level comparable to baseline values in the T and T/E groups, but higher by a mean of 1 ppb in the E group.
Active cigarette smoking or e-cigarette use also significantly affected the temperature of exhaled air, with statistically significant increases observed at one minute and 30 minutes after e-cigarette use in both the E and T/E groups.
Taken together, the authors state, "The use of e-cigarettes is associated with decreased FeNO and airflow indices (PEF, MEF75), but an increase in airway temperature. These changes are similar to those after exposure to tobacco cigarette smoke."
Dr. Monica Webb Hooper, a professor at Case Western Reserve University School of Medicine in Cleveland and Director, Office of Cancer Disparities Research, Case Comprehensive Cancer Center, told Reuters Health by email, "These findings add to a growing body of literature showing that measurable effects on respiration can be observed after only five minutes of e-cigarette exposure."
"As noted in the article, the full extent of acute respiratory and other physical consequences of vaping and dual use are not well-understood, and we are also still learning about the effects of combustible smoking after decades of research," she said.
"As evidence is emerging almost daily, clinicians should remain cautious in their recommendations regarding e-cigarette use," she added. "When talking with combustible cigarette smokers who are wondering whether they should try e-cigarettes to help them quit, the discussion should highlight the limited knowledge about their effectiveness for this purpose, and that health risks, including respiratory concerns have been identified."
"From a purely harm-reduction perspective, an exclusive switch to e-cigarettes from combustible smoking is a better option - if these are the only choices a patient is willing to consider," she concluded.
Dr. Krystal Cleven, a pulmonologist at Montefiore Health System and an assistant professor at Albert Einstein College of Medicine in New York City, called the study results "important and compelling."
"E-cigarettes are being used more often in young people and we as clinicians and researchers really have no idea how electronic nicotine delivery systems will affect health after several years or decades of use," she said in an email to Reuters Health.
"The results support many clinicians' concerns that e-cigarettes may be nearly as dangerous as traditional tobacco cigarettes," she said. "Certainly, longitudinal studies are needed on this topic. My concern is that we may not know the health effects of these new electronic nicotine delivery systems until respiratory and perhaps cardiovascular disease, as seen with traditional tobacco cigarettes, have already developed."
Dr. Brozek did not respond to requests for a comment.
Sci Rep 2019.