Dual vaping/cigarette use may be no safer than tobacco cigarette use alone
E-cigarette use combined with use of traditional cigarettes may confer similar inflammatory and oxidative stress to exclusive use of traditional cigarettes, according to research published in Circulation.
“Some people who smoke cigarettes pick up e-cigarette use to reduce the frequency with which they smoke cigarettes,” Andrew C. Stokes, PhD, assistant professor of global health at Boston University School of Public Health in Boston, said in a press release. “They often become dual users of both products rather than switching entirely from one to the other. If e-cigarettes are used as a means to quit smoking, cigarette smoking should be completely replaced and a plan to ultimately attain freedom from all tobacco products should be advised.”
For this investigation, researchers included 7,130 participants in the Population Assessment of Tobacco and Health (PATH) study, a nationally representative, longitudinal, U.S. cohort. Data were collected from the wave 1 survey of the study, which included the collection of blood and urine samples. Participants were categorized as nonusers of traditional or e-cigarettes, exclusive e-cigarette users, exclusive cigarette users or dual users of traditional and e-cigarettes.
Biomarkers for inflammation included high-sensitivity C-reactive protein, interleukin-6, soluble intercellular adhesion molecule and fibrinogen. Oxidative stress was measured as urinary 8-isoprostane.
“This study is among the first to use nationally representative data to examine the association of cigarette and e-cigarette use behaviors with biomarkers of inflammation and oxidative stress,” Stokes said in the release. “Given the lag time between tobacco exposure and disease symptoms and diagnosis, identifying the association between e-cigarette use and sensitive biomarkers of subclinical cardiovascular injury is necessary for understanding the long-term effects of newer tobacco products such as e-cigarettes.”
E-cigarette use vs. nonuse
Overall, 58.6% of participants were nonusers, 1.9% used e-cigarettes only, 29.6% smoked traditional cigarettes and 9.9% were dual users.
Researchers observed that exclusive users of e-cigarettes had similar inflammatory and oxidative stress as nonusers:
- hsCRP (geometric mean ratio [GMR] = 1.08; 95% CI, 0.92-1.27);
- interleukin-6 (GMR = 1; 95% CI, 0.89-1.12);
- soluble intercellular adhesion molecule (GMR = 1.05; 95% CI, 0.99-1.11);
- fibrinogen (GMR = 1; 95% CI, 0.96-1.04); and
- urinary 8-isoprostane (GMR = 1.02; 95% CI, 0.89-1.17).
Smoking and dual use
Participants in the exclusive tobacco smoking group and dual use group had greater levels of all biomarkers for inflammatory and oxidative stress compared with nonusers:
- hsCRP (GMR for exclusive tobacco smoking = 1.19; 95% CI, 1.06-1.33; GMR for dual use = 1.17; 95% CI, 1.03-1.32);
- interleukin-6 (GMR for exclusive tobacco smoking = 1.15; 95% CI, 1.07-1.23; GMR for dual use = 1.11; 95% CI, 1.03-1.19);
- soluble intercellular adhesion molecule (GMR for exclusive tobacco smoking = 1.19; 95% CI, 1.15-1.24; GMR for dual use = 1.16; 95% CI, 1.11-1.22);
- fibrinogen (GMR for exclusive tobacco smoking = 1.04; 95% CI, 1.02-1.06; GMR for dual use 1.03; 95% CI, 1-1.06); and
- urinary 8-isoprostane (GMR for exclusive tobacco smoking = 1.24; 95% CI, 1.15-1.34; GMR for dual use = 1.26; 95% CI, 1.15-1.37).
E-cigarettes vs. traditional cigarettes
Compared with exclusive tobacco smokers, those who exclusively used e-cigarettes had significantly lower levels of almost all inflammatory and oxidative stress biomarkers except for hsCRP (GMR = 0.91; 95% CI, 0.79-1.07):
- interleukin-6 (GMR = 0.87; 95% CI, 0.78-0.98);
- soluble intercellular adhesion molecule (GMR = 0.88; 95% CI, 0.83-0.93);
- fibrinogen (GMR = 0.96; 95% CI, 0.92-0.99); and
- urinary 8-isoprostane (GMR = 0.82; 95% CI, 0.72-0.93).
“This study adds to the limited body of research we have on biologic measures in those using e-cigarettes,” Rose Marie Robertson, MD, FAHA, deputy chief science and medical officer of the American Heart Association and co-director of the AHA’s NIH/FDA-funded Tobacco Center of Regulatory Science, said in the release. “I believe it has an important message for individuals who may believe using e-cigarettes while continuing to smoke some combustible cigarettes reduces their risk. This commonly seen pattern of dual use was not associated with lower levels of inflammatory markers, and thus is not likely to offer a reduction in risk in this specific area.”