Health impact of E-cigarettes: a prospective 3.5-year study of regular daily users who have never smoked

Abstract

Although electronic cigarettes (ECs) are a much less harmful alternative to tobacco cigarettes, there is concern as to whether long-term ECs use may cause risks to human health. We report health outcomes (blood pressure, heart rate, body weight, lung function, respiratory symptoms, exhaled breath nitric oxide [eNO], exhaled carbon monoxide [eCO], and high-resolution computed tomography [HRCT] of the lungs) from a prospective 3.5-year observational study of a cohort of nine daily EC users (mean age 29.7 (±6.1) years) who have never smoked and a reference group of twelve never smokers. No significant changes could be detected over the observation period from baseline in the EC users or between EC users and control subjects in any of the health outcomes investigated. Moreover, no pathological findings could be identified on HRCT of the lungs and no respiratory symptoms were consistently reported in the EC user group. Although it cannot be excluded that some harm may occur at later stages, this study did not demonstrate any health concerns associated with long-term use of EC in relatively young users who did not also smoke tobacco.

An online survey of Malaysian long-term e-cigarette user perceptions

“…Long-term EC usage had a threshold of ≥2 years, in accordance with recent prospective studies 15,16 . A current smoker was defined as an adult who smoked 100 cigarettes in his lifetime and who currently smokes conventional cigarettes 24 .…”

“…Another recent investigation, a 2-year longitudinal follow-up study in the US, found significantly higher tobacco quit attempts and cessation rates among EC users 15 . A prospective 3.5year observational study among a cohort of 9 never smokers who used ECs daily found no significant harmful health effects from EC use 16 . This study was, however, limited by its relatively small sample size.…”

Nicotine and the renin-angiotensin system

“…In young, normotensive nonsmokers, Fogt et al (48) found that e-cig inhalation preferentially increased both resting and exercise diastolic BP 40 min following nicotine inhalation. A recent prospective 3.5-yr observational study by Polosa et al (112) found that in a population of healthy e-cig users who had never smoked conventional cigarettes, there was no change in systolic or diastolic BP compared with healthy never smokers and non-e-cig users. The authors thus concluded that daily e-cig use is not associated with adverse health concerns.…”

Immunological and pathological effects of electronic cigarettes

“…Nitric oxide is involved in antimicrobial activity against lung pathogens and has anti‐tumour effects, whereas eCO is a biomarker of smoking that reflects airway inflammation; thus, normalization of FeNO and eCO might support the use of E‐cigarettes to reverse the harmful effects of CS in the lungs. A prospective 3.5‐year observational study of nine E‐cigarette users who never smoked conventional cigarettes found E‐cigarette use did not alter healthy outcome including blood pressure, heart rate, body‐weight, lung function, respiratory symptoms, exhaled breath nitric oxide (eNO), exhaled carbon monoxide (eCO) or high‐resolution computed tomography of the lungs …”

“…A prospective 3.5year observational study of nine E-cigarette users who never smoked conventional cigarettes found E-cigarette use did not alter healthy outcome including blood pressure, heart rate, body-weight, lung function, respiratory symptoms, exhaled breath nitric oxide (eNO), exhaled carbon monoxide (eCO) or high-resolution computed tomography of the lungs. 20 In addition to helping to reduce harmful effects in smokers with normal lung function, E-cigarette use may also benefit patients with respiratory and systemic diseases. COPD patients who switched to the use of E-cigarettes reduced their CS consumption, and more than half stopped cigarette smoking completely during a 12-month follow-up.…”