Nasal nitric oxide and lifestyle exposure to tobacco smoke

Nitric oxide (NO) is a reactive gas generated by inflammatory cells and mucosal epithelial cells of the nose and paranasal sinuses and is an important mediator in nonspecific host defense against infectious agents. However, NO also mediates physiologic events such as vasodilation, mucus hypersecretion, and mucosal disruption that are associated with inflammatory conditions, and it is a regulator of ciliary beat frequency. In the present study, we hypothesized that lifestyle exposure to tobacco smoke, whether through active smoking or by inadvertent exposure to secondhand tobacco smoke, would result in higher detectable levels of nasal NO (nNO) than are found in well-documented nonsmokers.

Nasal NO measurements were obtained concomitant with assays of urine cotinine from well-documented nonsmokers, active smokers, and individuals exposed by lifestyle to secondhand smoke. These parameters were statistically analyzed to determine whether increasing levels of tobacco smoke exposure yield higher concentrations of nNO.

Our results and subsequent statistical analyses imply that active smokers who exhibit high urine cotinine levels exhibit significant increases in nNO levels in comparison to both nonsmokers and nonsmokers exposed to secondhand smoke.

There is an increased level of nNO associated with tobacco smoke exposure that may contribute to the inflammatory processes characteristic of disease pathogenesis in smokers.