[Early diagnosis of small airways disease in young smokers (author's transl)].

Investigations during the past years have established that determinations of closing volume, flow-volume curves and frequency-dependent compliance are capable of detecting pathological changes in the bronchial system at a time when the customary lung function tests (FEV1.0 resistance as measured by bodyplethysmography) are still normal. These observations have been made use of to diagnose incipient damage in persons exposed to bronchial noxae. In the present investigation the effect of smoking on the airways was studied in a group of 25 persons aged 20-25 years by determining the closing volume and differences in ventilatory distribution (Thews method). The results were compared with those obtained in a group of 27 non-smokers in the same age group.