EFFECT OF ENVIRONMENTAL AND CLINICAL FACTORS ON LUNG-FUNCTION AND RESPIRATORY SYMPTOMS IN ADOLESCENTS WITH ALPHA(1)-ANTITRYPSIN DEFICIENCY

Individuals identified in the Swedish neonatal alpha 1-antitrypsin (AA T) screening study were followed prospectively from their first to the ir eighteenth year of life. The aim of this study was to analyse the e ffect of environmental factors, i.e. active and passive smoking, and o f clinical factors on lung function and the occurrence of respiratory symptoms in AAT-deficient adolescents. The study group consisted of 88 protease inhibitor (Pi)ZZ and 40 PiSZ adolescents. Medical history in cluding respiratory symptoms, and active and passive smoking were reco rded at each follow-up up to the age of 18 y. Lung function tests were performed at the present check-up. At the age of 18 y, both forced ex piratory volume in one second (FEV1) and FEV1/vital capacity (VC) were significantly lower in the smoking than in the non-smoking subgroup, and significantly more smokers than non-smokers reported the presence of phlegm. The mean FEV1/VC ratio was lower for those presently expose d to parental smoking. Multiple linear regression analysis indicated t hat clinical liver disease in early life, active smoking and parental smoking were independent determinants of FEV1/VC. The results suggest that marginal deviations in lung function and the symptom of phlegm am ong AAT-deficient adolescents occur characteristically early in the su bgroup of smokers. Parental smoking may contribute to decreased lung f unction.