Study: Heated Tobacco Products May Be Safer Than Combustible Cigarettes in COPD

Heated tobacco products operate by heating liquid containing tobacco and nicotine in a controlled manner through a battery supported device.

A review of published literature showcased the pros of patients with chronic obstructive pulmonary disease (COPD) switching from combustible cigarettes to heated tobacco products (HTPs), including reductions in exacerbation risks and exposure to toxic chemicals.

The researchers behind the analysis, which was published in European Journal of Medical Research, noted that although combustible cigarettes have benefits compared with HTPs, quitting smoking entirely is even more favorable for patients with COPD.

“There are differences in research results between HTPs and combustible cigarettes in favor of HTPs. More long-term studies are needed to look at the effects of HTPs, especially in COPD. However, there is no doubt that it would be best for patients to give up their nicotine addiction completely,” the researchers wrote.

COPD is estimated to affect 9% to 10% of adults older than 40 years globally. In 2017, 3.2 million people died of the disease, and COPD deaths are projected to reach 4.4 million annually by 2040. Smoking plays a major role in development of COPD, and nearly half of all deaths from COPD are regarded as being caused by smoking. Acute COPD exacerbations can have a serious impact on lung function and lead to increased mortality rates. Smoking and environmental pollution, airway infections, and other comorbidities are the major factors contributing to acute exacerbations.

HTPs, such as e-cigarettes and personal vaporizors, appear to be a less harmful method of delivering nicotine compared with traditional cigarettes. They operate by heating liquid containing tobacco and nicotine in a controlled manner through a battery-supported device. The assumption is that the aerosol delivered to the lungs should contain significantly lower concentrations of toxic substances than cigarette smoke, and some experts believe that noncombustible tobacco products could be a tool to help people quit smoking and that these products are a less detrimental alternative to cigarettes.

The current analysis sought to provide an in-depth understanding of the mechanisms leading to tissue damage in COPD and compare the effects of smoking on lung tissue with the accessible published information on alternatives to cigarettes.

Researchers found that there is less exposure to toxic substances like carbonyls or reactive oxygen species using HTPs. These products also show better results in clinical trials with fewer exacerbations in patients with COPD switching to HTPs compared with continuing smoking. The levels of tobacco exposure–related biomarkers improved following HTP use compared with smoking cigarettes. However, more long-term studies are needed to look at the effects of HTPs, especially in COPD. The authors emphasized that all tobacco products have a negative effect on lung tissue and can cause inflammation.

Overall, smoking induces epigenetic changes in patients with COPD. Genome-wide association studies (GWAS) have provided compelling evidence on the association between polymorphisms in CYP2A6, a nicotine-metabolizing enzyme, and nicotinic acetylcholine receptors (CHRNA3/CHRNA5/CHRNAB4) cluster with the number of cigarettes smoked per day both in the general population and the COPD population.

Moreover, GWAS including over 400,000 patients found more than 270 independent loci significantly associated with lung function parameters, such as forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), peak flow measurement, and FEV₁/FVC ratio, the last of which is an indicator of airflow obstruction.

When it comes to smoking cessation, estimates say that up to 40% of patients who have COPD, including those with severe disease, continue to smoke. Although smoking cessation programs have strong educational support about the harms of smoking and methods to cope with nicotine addiction, they are poorly reimbursed and often overlooked by national health care systems. So far, no studies assessing the effectiveness of HTPs for smoking cessation have confirmed this.

The authors called for more randomized, non–industry-funded trials to make a reliable assessment of HTP use by patients with COPD. Additionally, more long-term studies with good methodology are needed to determine the effectiveness of smoking cessation methods using HTPs. Long-term studies with appropriate biomarkers and lung function tests will also be needed to investigate whether switching from combustible cigarettes to HTPs reduces damage and the number of exacerbations in people with COPD.

Reference

Błach J, Siedliński M, Sydor W. Immunology in COPD and the use of combustible cigarettes and heated tobacco products. Eur J Med Res. 2023;28(1):397. doi:10.1186/s40001-023-01374-2