E-Cigarettes Dampen Cough Reflex

Just one exposure to vapor from electronic cigarettes dampens the cough reflex, a study from researchers in New York City shows.

Reporting at the 2015 American Thoracic Society annual meeting in Denver, Peter Dicpinigaitis, MD, of Albert Einstein College of Medicine and Montefiore Medical Center in the Bronx, and colleagues said that is a potentially unhealthy reaction.

The cough reflex is designed to protect the upper respiratory system from the entrance of foreign material. Apparently, he said, the reduced sensitivity is caused by desensitization of the airway’s cough receptors.

The 30 subjects in the study were all healthy adults who had never smoked.

The team measured their cough reflex sensitivity by having them inhale capsaicin in increasing doses until the inhaled extract made them cough 5 times.

They did this to establish a baseline measuring how much capsaicin it took to make them cough repeatedly.

Next they were exposed to an e-cigarette. Their responses to the capsaicin where then measured 15 minutes later and again 24 hours later.

The e-cigarette sessions each involved 30 puffs of a disposable e-cigarette marketed under the brand name Blu (Lorillard Technologies) with each puff 30 seconds apart.

That resulted in a nicotine exposure equivalent to a tobacco cigarette (1.5 mg to 1.8 mg of nicotine).

The researchers found that cough reflex sensitivity was significantly diminished when tested 15 minutes after inhaling e-cigarette vapor, but that it returned to normal 24 hours later.

They concluded, however, that “the clinical significance, if any, of the transient, acute effect that we have demonstrated, as well as the consequences of chronic electron cigarette exposure remain to be elucidated.”