Influence of Time and Frequency of Passive Smoking Exposure on Mucociliary Clearance and the Autonomic Nervous System

BACKGROUND: There are still gaps in the knowledge regarding the damage to mucociliary and autonomous systems from passive exposure to cigarette smoke. Also, the influence of the frequency and duration of exposure on these systems is still unclear. The objective of this work was to verify the effects of passive smoking on mucociliary clearance and adult autonomic nervous systems and investigate the influence of frequency and time of passive exposure on these systems. METHODS: 44 smokers (smoking group), 38 passive smokers (passive smoking group), and 38 healthy individuals (control group) were evaluated. Evaluation of lung function was performed. To analyze the autonomic nervous system, heart rate variability data were collected. Hemodynamic parameters were collected. Mucociliary clearance was evaluated using the saccharin transit time test. RESULTS: The passive smoking group presented reduced lung function (P = .02). Systolic blood pressure was significantly greater in the passive smoking group when compared with the smoking group (P = .02). The passive smoking group presented significantly slower transportability time than the control group. No differences were observed between the groups for the heart rate variability data. There was a significant correlation (P < .05) between the frequency of exposure and diastolic blood pressure, oxygen saturation, and FEF25-75%. Correlation analyses also demonstrated a reduction of global autonomic activity according to exposure load, in addition to a reduction in vagal activity and an increase in sympathetic activity according to exposure frequency. CONCLUSIONS: Passive smokers presented worse mucociliary clearance, and there was a correlation between passive exposure load and damage to the hemodynamic response, pulmonary function and autonomic nervous system.