Study Finds Adults Who Use ENDS Have Increased Risk of Asthma Incidence at Earlier Ages

Asthma is one of the most prevalent respiratory diseases, and cigarettes or combustible product use is associated with an increased risk of asthma onset in users. The use of electronic nicotine delivery systems (ENDS) has also increased in popularity in the United States, with nicotine users opting to use vapes, electronic cigarettes (e-cigarettes), or hookah pens instead of non-electronic nicotine products. ENDS were proven to have harmful chemical ingredients that can affect pulmonary function and potentially negatively influence respiratory health; however, there is no sufficient data specifically related to age of asthma onset and the association of prevalence of past 30-day (P30D) ENDS use in youths and adults. Authors of a JAMA Network Open study evaluate the potential risk of earlier asthma onset because of P30D ENDS use to either prevent initial use or motivate users to stop.

This cohort study is a secondary analysis of waves 1 to 6 of the United States nationally representative Population of Tobacco and Health Study, which was conducted from 2013 to 2021. Wave 1 was collected in 2013 to 2014, wave 2 in 2014 to 2015, wave 3 in 2015 to 2016, wave 4 in 2016 to 2017, wave 4.5 in 2017 to 2018, wave 5 in 2018 to 2019, wave 5.5 in 2019 to 2020, and wave 6 in 2020 to 2021. Patients who were eligible consisted of adults aged 18 years or older and youths aged 12 to 17 who did not have asthma or chronic obstructive pulmonary disease (COPD) at the time of the first wave of participation.

During the previous waves, adult participants were asked if they were told by a physician or other health care professional that they had asthma or COPD, and if the answer was no at the time of the first wave, they were asked about asthma diagnosis in the past 12 months during waves 2 through 6. Additionally, parents of youths who participated were asked to participate to help enhance the accuracy of some responses. Youths without asthma at the first wave of study participation were asked about asthma diagnosis in the past 12 months using waves 2 to 6. The authors note that COPD was not measured in youths.

During waves 1 and 2, P30D ENDS use was measured based on patients’ responses to whether they used an e-cigarette within the past 30 days, even if it was minimal (1 or 2 times). Similarly, during waves 3 to 5.5, use was measured based on patients’ responses to whether they used an ENDS, even if use was minimal.

Participants’ birthdays were not provided and because the exact date of asthma onset was not assessed, the age at the time of the first wave of study participation and the number of weeks between survey dates were used to estimate the age of asthma onset. Further, lower and upper age bounds of asthma onset were estimated for the time-to-event analyses, and the age of asthma onset was estimated to occur between the lower and upper age bounds in all participants.

A total of 24,789 participants were enrolled at the first wave of participation (adults: n = 7766; youths: n = 17,023). The findings indicate that among adults without asthma or COPD and who never used cigarettes, about 6.2 per 1000 adults reported the occurrence of asthma by 27 years of age (HR, 0.62%; 95% CI, 0.46%-0.75%), by 35, about 10.8 per 1000 adults reported experiencing asthma (HR, 0.62%; 95% CI, 0.46%-0.75%), and by 55, about 25.8 per 1000 adults reported the incidence of asthma (HR, 0.62%; 95% CI, 0.46%-0.75%). In addition, about 22.3 per 1000 youths reported the incidence of asthma by 15 years of age (HR, 2.23%; 95% CI, 1.88%-2.45%), and 79.6 per 100 reported by 20 years of age (HR, 7.96%; 95% CI, 7.31%-8.61%).

Further, when adjusting for covariates, there were no observed association of P30D ENDS use with the age of asthma onset (HR, 1.79; 95% CI, 0.67-4.77), and when reducing the number of covariates, results were similar. Compared to adults who never reported using tobacco product (TP) and P30D ENDS use, adults who reported P30D use of any combustible TP and no P30D ENDS use had an approximate 69% increased risk of earlier age of asthma onset (HR, 1.69; 95% CI, 1.25-2.29) and adults who reported P30D use of any combustible TP and P30D ENDS use had a 143% increased risk (HR, 2.43; 95% CI 1.71-3.34). The investigators also noted there was no association found between the interaction of P30D use of any combustible TP and P30D ENDS use with the age of asthma onset in youths.

Limitations of the study include the factors associated with age of asthma onset, such as environmental factors, allergies, dust mites, maternal smoking status, family history, and nutritional intake, which were not included in the PATH Study; the association of other covariates with the age of asthma onset were reported but not discussed; and the PATH study did not ask participants for the exact date of their asthma diagnosis. The investigators note that the analysis was limited to evaluate the association of P30D ENDS use with the age of asthma onset, with secondary hypotheses evaluating the interaction of P30D ENDS use by sex as well as race and ethnicity are in preparation.

According to the investigators, modifying the screening guidelines for asthma to implement P30D ENDS use may result in early detection of asthma and lead to better symptom control with loser doses of medication, fewer adverse events, and improved treatment outcomes. Additionally, they note that prevention and cessation programs that are specifically catered to ENDS use are necessary to lessen its influence on the age of asthma onset.

Reference

Pérez, A, Valencia, S, Jani, PP, Harrell, MB. Use of Electronic Nicotine Delivery Systems and Age of Asthma Onset Among US Adults and Youths. JAMA Netw Open. 2024;7(5):e2410740. doi:10.1001/jamanetworkopen.2024.10740