RT Journal Article SR Electronic T1 Interactions between SERPINA1 PiMZ genotype, occupational exposure and lung function decline JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP 234 OP 240 DO 10.1136/oemed-2013-101592 VO 71 IS 4 A1 A J Mehta A1 G A Thun A1 M Imboden A1 I Ferrarotti A1 D Keidel A1 N Künzli A1 H Kromhout A1 D Miedinger A1 H Phuleria A1 T Rochat A1 E W Russi A1 C Schindler A1 J Schwartz A1 R Vermeulen A1 M Luisetti A1 N Probst-Hensch A1 SAPALDIA team YR 2014 UL http://oem.bmj.com/content/71/4/234.abstract AB Objectives We evaluated interactions between SERPINA1 PiMZ genotype, associated with intermediate α1-antitrysin deficiency, with outdoor particulate matter ≤10 µm (PM10), and occupational exposure to vapours, dusts, gases and fumes (VGDF), and their effects on annual change in lung function. Methods Pre-bronchodilator spirometry was performed in 3739 adults of the Swiss Cohort Study on Air Pollution and Lung Disease in Adults (SAPALDIA) for whom SERPINA1 genotypes were available. At baseline in 1991, participants were aged 18–62 years; follow-up measurements were conducted from 2001 to 2003. In linear mixed regression models of annual change in lung function, multiplicative interactions were evaluated between PiMZ genotype (PiMM as reference) and change in PM10 (μg/m3), and VGDF exposure (high-level, low-level or no exposure as reference) during follow-up. Results Annual declines in forced expiratory flow at 25–75% of forced vital capacity (FEF25–75%) (−82 mL/s, 95% CI −125 to −39) and forced expiratory volume in 1 s over forced vital capacity (FEV1/FVC) (−0.3%, 95% CI −0.6% to 0.0%) in association with VGDF exposure were observed only in PiMZ carriers (Pinteraction<0.0001 and Pinteraction=0.03, respectively). A three-way interaction between PiMZ genotype, smoking and VGDF exposure was identified such that VGDF-associated FEF25–75% decline was observed only in ever smoking PiMZ carriers (Pinteraction=0.01). No interactions were identified between PiMZ genotype and outdoor PM10. Conclusions SERPINA1 PiMZ genotype, in combination with smoking, modified the association between occupational VGDF exposure and longitudinal change in lung function, suggesting that interactions between these factors are relevant for lung function decline. These novel findings warrant replication in larger studies.