Study shows e-cigarettes not linked to wheezing risk

By Pooja Toshniwal PahariaReviewed by Benedette Cuffari, M.Sc.Apr 10 2023

In a recent study published in JAMA Network Open, researchers analyze the longitudinal association between electronic nicotine delivery systems (ENDS), cigarette use, and self-documented wheezing among adults in the United States.

Study: Assessment of Electronic Nicotine Delivery Systems With Cigarette Use and Self-reported Wheezing in the US Adult Population. Image Credit: Parkin Srihawong / Shutterstock.com

Background

The growing popularity of ENDS products, particularly among young adults, has increased concerns regarding their toxicity and outcomes regarding the respiratory effects of ENDS-only usage and the synergistic risks of combined use of ENDS and other tobacco products. Previous studies have reported on the relationship between smoking and wheezing, a commonly observed symptom in respiratory disorders; however, data on the impact of ENDS usage on the risk of wheezing are limited.

Moreover, most studies assessing the relationship between ENDS usage and wheezing had cross-sectional study designs and analyzed data from only the first and second waves of the U.S. Population Assessment of Tobacco and Health (PATH) study.

About the study

In the present study, researchers assessed the relationship between smoking, ENDS usage, and wheezing among U.S. adults.

Longitudinal data were obtained from the U.S. PATH study for adults from the first PATH study wave (between September 2013 and December 2014) to the fifth wave (between December 2018 and November 2019). The primary study outcome was the prevalence of self-documented wheezing between the second (between October 2014 and October 2015) and fifth PATH waves.

Wheezing prevalence was estimated for six categories of tobacco products consumption, including never smoking and non-current ENDS use, never smoking and current ENDS use, current smoking and non-current ENDS usage, current smoking, and current ENDS usage, former smoking and non-current ENDS usage, and former smoking and current ENDS usage.  

Generalized estimating equations (GEE) were used, and marginal logistic regression modeling was performed to determine the relationship between smoking, ENDS usage, and wheezing. The adjusted odds ratios (AOR) values were calculated, adjusting for age, sex, ethnicity and race, household income, history of respiratory diseases, obesity, and passive smoking.

Results

The sample comprised 17,075 adult U.S. residents, among whom the average age was 45 years, 51% were women, 66% were non-Hispanics, 50% were passive smokers, and 16% had a prior history of pulmonary disorders.

Wheezing prevalence reduced slightly from 16% in the second wave to 14% in the fifth wave, with the most significant frequency during the second wave. Current smoking prevalence was consistent across the four waves, ranging between 18% and 19%, with 23% of the population sampled reporting cigarette smoking for one or more years between the first and fourth PATH study waves.

In comparison, 6% of adults used ENDS one or more times; however, ENDS usage remained similar across waves for many study participants. More specifically, current electronic nicotine delivery system users were 3%, 4%, 3%, and 3% of the sample population in the first, second, third, and fourth waves, respectively. Only 0.3% of participants used ENDS exclusively.

Wheezing was most prevalent at over 30% among current smokers and non-current ENDS users, as well as among current smokers and current ENDS users, across PATH waves. Wheezing prevalence was the least among those who never smoked or used ENDS at 10% in the second wave and 9% in the fifth wave, as well as those who previously smoked and did not currently use ENDS.

Among never-smokers current ENDS users, self-documented wheezing prevalence varied between 24% in the second wave and 13% in the fifth wave. Compared to never smoking and non-current ENDS usage, the greatest association with wheezing was observed for current smokers and current ENDS users (AOR 3.3) and current smokers and non-current ENDS users (AOR 3.2). The association was considerably greater for former smokers and current ENDS users, with an AOR of 1.9.

Small and non-significant associations were observed for the probability of self-documented wheezing in the ENDS exclusive usage group compared to the never-smoking and non-current ENDS usage group (AOR 1.2). Similarly, the probability of wheezing, current smoking, and current ENDS usage had small and non-significant associations compared to that for current smokers and non-current ENDS users (AOR 1.0).

ENDS usage was not related to self-documented wheezing at follow-up (AOR 1.1); however, former and current smoking showed positive associations with AOR values of 1.5 and 3.2, respectively. A 10% increase in the probability of wheezing was observed with every 10-year increase in age. This probability was 59% greater for obese adults with AOR values of 1.1 and 1.6, respectively.

Non-Hispanic Blacks and Hispanics showed a lower probability of documenting wheezing with AOR values of 0.7 and 0.6, respectively, as compared to non-Hispanic Whites. Compared to individuals with annual income exceeding $100,000, those with income below $50,000 showed a greater probability (AOR 1.4) of wheezing. Women also had a lower probability of reporting wheezing compared to men (AOR 0.9).

In comparison to non-passive smokers, adults with less than seven hours of weekly exposure to second-hand smoke (AOR, 1.3) and over seven hours of weekly exposure (AOR 1.9) showed a greater probability of reporting wheezing. An AOR value of 6.8 was observed for the relationship between self-documented wheezing and prior pulmonary disease history.

Conclusions

Overall, the study findings showed that exclusive ENDS usage did not increase the risk of wheezing. However, a small rise in the risk between ENDS usage and wheezing was documented by cigarette smokers.  

Self-documented wheezing showed the greatest association with current dual users of ENDS and cigarettes, followed by current smokers and non-current ENDS users and those who smoked formerly and currently used ENDS.

Taken together, the study findings could inform population health policy-making for ENDS usage among various categories of tobacco product use.