Electronic cigarettes help reduce exacerbations and improve exercise capacity in patients with chronic obstructive pulmonary disease (COPD) who saw their condition get worse by smoking conventional cigarettes, a new study reports.
The study, “Health effects in COPD smokers who switch to electronic cigarettes: a retrospective-prospective 3-year follow-up” was published in the International Journal of Chronic Obstructive Pulmonary Disease.
The use of e-cigarettes has been proposed as a potential strategy to reduce tobacco’s harm. They do not contain tobacco and, while not risk-free, the chemicals they emit are substantially lower than those in conventional cigarette smoke.
The impact of electronic cigarettes in smokers with COPD, however, remains unknown.
Researchers performed a long-term study to assess respiratory health outcomes in 44 COPD patients split into two groups: those who quit or significantly reduced conventional cigarette smoking by switching to electronic cigarettes (22 patients), and those who continued to smoke conventional tobacco (22 patients), the control group.
COPD patients from both study groups (e-cigarette users and controls) were followed for 36 months.
Researchers evaluated patients’ cigarette use and respiratory parameters, including COPD exacerbations and the disease’s impact on their lives (assessed by COPD Assessment Test scores), lung function, and exercise activity — evaluated with the 6-minute walk distance test (6MWT), which measures the maximum distance a person is able to walk over six minutes on a hard, flat surface.
The team compared COPD patients’ scores prior to switching to electronic cigarettes to that at follow-up visits at 12, 24, and 36 months.
Results showed that COPD patients using e-cigarettes significantly reduced their conventional cigarette use. At the beginning of the study (baseline) they smoked a mean of 21.9 cigarettes a day, while at 1-year follow-up they smoked a mean of 2 cigarettes a day, and 1.5 cigarettes a day at 3-year follow-up. No marked changes were observed among COPD controls regarding the number of conventional cigarettes smoked per day.
Almost 60 percent (13 of 22) of the COPD electronic cigarette users quit smoking conventional cigarettes by year 3, while the remaining nine used both electronic and conventional cigarettes.
Among the dual users, at all three periods assessed, there was a significant reduction — 75 percent or more — of their conventional cigarette use per day compared to baseline.
COPD exacerbations dropped significantly among the COPD users of e-cigarettes, falling from a mean of 2.3 at baseline to 1.7 (1-year follow up), 1.4 (2-year follow up), and 1.3 (3-year follow up). No significant changes in COPD exacerbation rates over the 36 months were seen in the control (conventional cigarette) group.
Researchers also saw a significant decline in COPD exacerbation rate among dual users — from a mean of 2.7 at baseline to 1.5 and 1.2 at 2- and 3-year follow up visits.
Lung function, measured by forced expiratory volume in one second (FEV1) and forced vital capacity (FVC), remained unchanged throughout the study in both groups.
Patient scores on the COPD Assessment Test also improved significantly among COPD users of e-cigarettes throughout the study, while no differences were detected in the control group.
The exercise capacity of COPD patients using electronic cigarettes also improved, with their results in the 6MWT improving by a median of 70 meters (almost 230 feet) at the end of the 36 months, compared to a decrease of 7.5 meters (24.6 feet) in the control group.
“While the sample size in the study was relatively small, the results may provide preliminary evidence that long-term use of ECs [electronic cigarettes] is unlikely to result in substantial health concerns in COPD patients,” researchers wrote.
“Quitting smoking is a key strategy not only to prevent the onset of COPD, but also to stop its progression to more severe disease stages,” Riccardo Polosa, MD, PhD, professor of internal medicine at the University of Catania, Italy and the study’s leader, said in a press release.
“Given that many COPD patients continue smoking despite their symptoms, the electronic cigarette could be an effective and safe alternative to the tobacco cigarettes also in this vulnerable population,” he said.
During the study, only two patients (8.3%) relapsed to cigarette smoking, and they were both dual users. This is a key finding, as smokers with COPD are known to have difficulties quitting.
The team concluded that electronic cigarette use “may ameliorate objective and subjective COPD outcomes and that the benefits gained may persist long-term.”
The findings also suggests that “relapse prevention may be another way by which [electronic cigarettes] contribute to individual and public health,” they wrote.
“The finding that COPD exacerbations were halved in patients who stopped or considerably reduced their smoking habit following switching to [electronic cigarettes] was an important finding that confirms the potential for harm reversal of these products,” wrote Pasquale Caponnetto, PhD, a behavioral psychologist at the Center for Tobacco Prevention and Cessation (CPCT) of the University of Catania, and the study’s lead author.