[Relation between respiratory function, bronchial reactivity and symptoms in heavy smokers].

As part of a study of the morphology of hyperreactive airways, 22 heavy smokers (67 +/- 31 pack-years), all male, were challenged with histamine, questioned on symptoms and skin-tested for common allergens before thoracic surgery, mainly for cancer. Histamine was delivered with a hand operated nebulizer in a total dose of 7.8 mumol or a 20% fall from the baseline FEV1. The PD20 (dose of histamine which causes a 20% fall of FEV1) was determined on a semi-log dose-response curve. Symptoms were recorded by physician-administered questionnaire and skin tests were performed with 8 common allergens. Values for FEV1%VC ratio and response to salbutamol were taken from preoperative spirometric studies. Bronchial hyperresponsiveness (BHR) was found in 45% of the patients. The PD20 was in the range of asthma. Past symptoms of airway allergy did not enhance BHR risk. Half of the 13 subjects with airway obstruction (FEV1%VC of less than 2 SD of the predicted value) had normal bronchial responsiveness; however, PD20 correlated well with FEV1 (% predicted) in the hyperresponsive group (r = 0.90, p less than 0.001). The degree of BHR was unrelated to tobacco consumption, number of positive skin tests and response to salbutamol. Symptoms were those of chronic bronchitis and bronchoconstriction (wheezing, morning chest tightness, sudden dyspnea), as well as cough. They were experienced, to some extent, by 82% of patients, only half of whom had BHR. These smokers with BHR differed from asthmatics in that half of them did not report bronchoconstriction symptoms and none experienced chest discomfort during provocation.(ABSTRACT TRUNCATED AT 250 WORDS)