Association of cigarette smoking with increased use of heated tobacco products in middle-aged and older adults with self-reported chronic obstructive pulmonary disease, asthma, and asthma-COPD overlap in Japan, 2022: the JASTIS study

BACKGROUND: Smoking cessation is the most important intervention in chronic obstructive pulmonary disease (COPD), asthma, and asthma-COPD overlap (ACO); however, high rates of current cigarette smoking are observed in adults with these respiratory diseases. Meanwhile, rapidly increasing use of heated tobacco products (HTPs) is observed in Japan; however, the status of HTPs use has not been fully understood in adults with COPD, asthma, and ACO. This study aimed to reveal the association between COPD, asthma, and ACO and HTPs use in adults. METHODS: Data on Japanese individuals ≥ 40 years old obtained from the Japan Society and New Tobacco Internet Survey were analyzed. The prevalence of HTPs use in adults with COPD, asthma, and ACO, among individuals categorized into three groups according to cigarette smoking (never, former, and current), was calculated and the relationship between each disease and HTPs use were evaluated. The clinical diagnosis of these diseases was based on the self-reported diagnosis, as obtained from questionnaires. RESULTS: A total of 19,308 individuals were included. The proportions of never, past, and current cigarettes smokers were 10,900 (56.5%), 4,903 (25.4%), and 3,505 (18.2%), respectively, and that of HTPs use was 1,813 (9.4%). In current cigarettes smokers, the adjusted odds ratios (ORs) of HTPs use was 2.88 (95% CI [confidence interval], 1.86–4.47), 1.23 (95% CI, 0.99–1.52), and 5.81 (95% CI, 3.12–10.82) in adults with COPD, asthma, and ACO compared to those without these respiratory diseases, respectively. Meanwhile, in past cigarettes smokers, the adjusted ORs of HTPs use was 0.51 (95% CI, 0.24–1.08), 0.69 (95% CI, 0.53–0.88), and 0.25 (95% CI, 0.06–1.07) in adults with COPD, asthma, and ACO, respectively. CONCLUSIONS: HTPs use is more prevalent among current cigarettes smokers with COPD, asthma, and ACO compared to those without these respiratory diseases. Complete cessation of smoking both cigarettes and HTPs is the only way to achieve complete smoking cessation, therefore, adults with COPD, asthma, and ACO need to make greater efforts to quit smoking.