HRCT findings in secondhand smokers with respiratory symptoms

The present study aims to investigate the occurrence and severity of HRCT abnormalities in symptomatic never-smokers, passively exposed to cigarette smoke.

A total of 135 never-smokers with respiratory symptoms, without underlying lung disease, underwent paired inspiratory-expiratory HRCT and completed the secondhand smoking (SHS) exposure scale questionnaire. Individuals passively exposed to tobacco consisted the secondhand smoking group (SHS group) (n = 68); the remaining 67 controls were never exposed to SHS. Statistical analysis was performed using the Kolmogorov-Smirnov, x² and Pearson Point-Biserial correlation tests. P < 0.05 was statistically significant.

HRCT findings in SHS group included bronchial wall thickening (98.5%), mild cylindrical bronchiectasis (44%), ground-glass opacities (17.6%), and mosaic attenuation pattern (53%). Air trapping occurred in 65% of expiratory scans. Differences in occurrence of findings between SHS group participants and controls were statistically significant (p < 0.0001). There was significant correlation between exposure to tobacco smoke in hours/day and in number of cigarettes/day and the presence of mosaic attenuation pattern, ground-glass opacities, cylindrical bronchiectasis and air trapping, respectively (p < 0.05). Cumulative SHS exposure in years was also strongly correlated with the presence of ground-glass opacities, mosaic attenuation pattern, cylindrical bronchiectasis, and air trapping, as well as with the frequency of respiratory symptoms (p < 0.05).

HRCT findings attributed to SHS are mostly related to airway involvement and are correlated with the duration and grade of exposure to environmental tobacco smoke. SHS followed by lifestyle adjustments should be considered in symptomatic non-smokers with such HRCT findings.