Relationship of airway conductance and its immediate change on smoking to smoking habits and symptoms of chronic bronchitis.

Abstract

Measurements of airway conductance (Gaw) and thoracic gas volume (Vtg) were made on 508 workingmen before and after smoking a cigarette and on 202 men before and after a control period. The results are presented as loge of the specific conductance (SGaw = Gaw/Vtg) to permit valid analysis of the changes caused by smoking. Despite poor reproducibility in a subs ample of men and a wide range of responses to smoking, including bronchodilation as well as bronchoconstriction, the mean change on smoking (+0.053) was significantly different from the smaller change (−0.060) after a control period. A multiple regression analysis showed that the main factor related to the smoking response was current cigarette consumption, and the heavier smokers tended to show more pronounced bronchoconstriction than lighter smokers or nonsmokers. Smokers who inhaled had a greater response than those who did not inhale. This effect was independent of symptoms of bronchitis or level of forced expiratory volume, which had no effect ...