E-Cig Smoking Linked to Drop in Cough Reflex Sensitivity
(HealthDay News) — Electronic cigarette (e-cig) smoking is associated with a transient decrease in cough reflex sensitivity, and exposure to some flavors of e-cigs correlates with adverse effects on cells, according to two studies presented at the annual meeting of the American Thoracic Society, held from May 15–20 in Denver.
Peter V. Dicpinigaitis, MD, from the Albert Einstein College of Medicine in Bronx, NY, and colleagues measured cough reflex sensitivity in 30 healthy adult lifetime nonsmokers. They employed the capsaicin cough challenge at baseline, 15 minutes after e-cig exposure, and 24 hours later. The researchers found that cough reflex sensitivity was significantly diminished after e-cig exposure versus baseline (P<0.0001). The effect was transient, with enhancement of cough reflex sensitivity back to baseline levels at 24 hours after exposure (P=0.0002).
Temperance R. Rowell, from the University of North Carolina at Chapel Hill, and colleagues examined the effects of 13 flavors of e-cig liquid on airway epithelial calcium signaling, cell viability, and cell proliferation. Calu3 cells were seeded and exposed to various doses of the flavors for 30 minutes or 24 hours. The researchers found that certain flavors evoked a strong calcium response and cytotoxicity in higher doses during the 30-minute exposure. After the 24-hour exposure, these same flavors decreased cell proliferation and the ability of cells to respond to a pharmacologic agent that releases internal calcium stores.
"A number of cell viability and toxicity parameters pointed to five of 13 flavors tested showing overall adverse effects to cells in a dose-dependent manner," Rowell said in a statement.