Use of e-cigarettes plus tobacco cigarettes linked to higher risk of respiratory symptoms

Exclusively using (or "vaping") e-cigarettes can help people quit smoking, but many people using e-cigarettes to quit smoking continue to smoke cigarettes. New research led by investigators at Massachusetts General Hospital (MGH) reveals that respiratory symptoms—such as cough and wheeze—are more likely to develop when people use both e-cigarettes and tobacco cigarettes together compared with using either one alone. The findings are published in the American Journal of Respiratory and Critical Care Medicine.

The investigators analyzed information on 20,882 individuals aged 12 years and older in the Population Assessment of Tobacco and Health (PATH) Study, a U.S. nationally representative longitudinal survey.

The analyzed participants had no respiratory symptoms when surveyed in 2015-2016. When they were surveyed about one year later, respiratory symptoms were reported by 10.7% of those who did not use e-cigarettes or tobacco cigarettes, 11.8% of exclusive e-cigarette users, 17.1% of exclusive tobacco smokers, and 19.7% of dual users (those who both vaped e-cigarettes and smoked tobacco cigarettes). Dual users had a 1.9-times higher odds of developing respiratory symptoms compared with exclusive e-cigarette users and a 1.24-times higher odds compared with exclusive tobacco smokers. The risk of new respiratory symptoms among individuals who vaped but did not smoke was not significantly higher than the risk among individuals who neither vaped nor smoked.

"To help people quit smoking, FDA-approved medications, such as the nicotine patch or the medication varenicline, are preferred," says lead author Krishna Reddy, MD, MS, an investigator in MGH's Division of Pulmonary and Critical Care Medicine and the MGH Tobacco Research and Treatment Center. "People who vape e-cigarettes in an effort to stop smoking tobacco cigarettes should be cautioned against using both and instead should switch over completely from smoking to vaping, with an ultimate goal of stopping vaping as well."

Senior author Nancy Rigotti, MD, director of the Tobacco Research and Treatment Center, adds: "This study helps identify how e-cigarettes can best be used to reduce the harms caused by smoking cigarettes. Exclusive e-cigarette use did not increase the risk of new respiratory symptoms while using both products (e-cigarettes and cigarettes) did."