Effect of age and occupational exposure to airway irritants on lung function in non-smoking individuals with α1-antitrypsin deficiency (PiZZ)

Abstract

Background: Severe α1-antitrypsin (AAT) deficiency (PiZZ) is associated with an increased risk of lung emphysema, especially in smokers. The aim of this study was to identify risk factors other than smoking for declining lung function. Methods: Lung function was studied in 225 self-reported never-smoking PiZZ individuals included in the Swedish AAT deficiency register. Results: Lung function was poorer in men than in women (mean (SD) forced expiratory volume in one second (FEV1) 80 (30) versus 88 (17)% predicted) despite the fact that the men were younger (mean (SD) age 45 (18) versus 51 (17) years), and poorer in those aged 50 or older than in those aged under 50 (mean (SD) FEV1 70 (30) versus 98 (16)% predicted). Self-reported occupational exposure to gas, fumes, or dust occurred more frequently in men than in women. In those aged 50 or older lung function was lower in individuals exposed to airway irritants than those who were not exposed (mean (SD) FEV1 63 (29) versus 76 (31)% predicted). Male sex, increasing age, and previous symptoms of wheezing were independent risk factors for lung function impairment, and male sex, wheeziness, and occupational exposure to airway irritants were independent risk factors in the subjects aged 50 years or more. Conclusions: In non-smoking PiZZ individuals lung function declines with increasing age, especially after 50. Men are at greater risk of lung function deterioration than women. Asthmatic symptoms and occupational exposure to airway irritants appear to constitute additional risk factors.