ABSTRACT: Rationale: Minority sexual identity appears to confer asthma risks. Although associations between inhaled substances and asthma are established, these have not been examined among sexual minority youths. Given sexual minority adolescents' disproportionately high rates of substance use, research is needed to fill this important gap.Objectives: Using a representative sample of adolescents from the United States, we 1) examined associations among asthma, sexual identity, and inhaled substance use and tested 2a) whether sexual identity moderates relationships between asthma and inhaled substance use and 2b) whether inhaled substance use mediates associations between sexual identity and asthma.Methods: Data are from the 2015 and 2017 Youth Risk Behavior Surveillance Survey. Adolescents (n = 30,113) reported if they were ever diagnosed with asthma, current use of cigarettes, cigars and/or cigarillos, marijuana, and electronic vapor products and if they ever used inhalants or synthetic marijuana. We used logistic regression to examine associations between asthma, sexual identity, and inhaled substance use controlling for age, race or ethnicity, and body mass index percentile, stratified by sex.Results: Lesbian, gay, and bisexual respondents had higher relative risks for asthma than heterosexual youth. Sexual minority female youths had significantly higher relative risks than heterosexual female youths for use of every inhaled substance. There were few sexual identity differences in inhaled substance use among male youths. Inhaled substance use was significantly associated with higher risks for asthma. In general, associations between each individual inhaled substance and asthma did not differ between sexual minority and heterosexual youths. However, when all inhaled substances were added into the models concurrently, inhaled substance use appeared to mediate associations with asthma among lesbian and bisexual female youths, and partially mediated these associations among sexual minority male youths.Conclusions: Sexual identity and inhaled substance use appear to play important roles in asthma risk. However, these variables do not fully explain the risk, suggesting that other unmeasured variables (e.g., stress and victimization) may be implicated in risks for both inhaled substance use and asthma. It is important that clinicians providing care to adolescents ask about sexual identity and inhaled substance use. Effective approaches to reducing inhaled substance use among adolescents, especially sexual minorities, are needed.
