Table 2

Adjusted differences* in annual change in lung function in association with outdoor PM10 and occupational VGDF exposures during follow-up in PiMZ and PiMM carriers

NΔFEV1 (mL)ΔFVC (mL)ΔFEV1/FVC (%)ΔFEF25–75% (mL/s)
β (95% CI)†β (95% CI)†β (95% CI)†β (95% CI)†
▵PM10 (per 10 μg/m3 increase in 10 years)
 PiMZ97−6 (−15 to 4)−2 (−18 to 15)−0.2 (−0.4 to 0.0)−24 (−52 to 4)
 PiMM3642−3 (−7 to 0)−0 (−5 to 5)−0.0 (−0.1 to 0.0)−12 (−21 to −3)
High-level VGDF exposure
 PiMZ97−8 (−27 to 11)10 (−16 to 35)−0.3 (−0.6 to 0.0)‡−82 (−125 to 39)‡
 PiMM36421 (−2 to 4)−2 (−7 to 2)0.1 (0.0 to 0.1)6 (−1 to 13)

  • *Annual change in lung function was modelled in linear mixed regression with random intercept for area consisting of the following baseline covariates: age, age squared, sex, foreign status, height, body mass index, early respiratory infection, parental asthma, high-level education, cumulative VGDF exposure, and outdoor PM10; additional covariates included smoking status through follow-up, cumulative pack-years through follow-up, daily environmental tobacco smoke exposure at follow-up, difference in body mass index over follow-up period, seasonality, ▵PM10, high-level VGDF exposure during follow-up, and two-way interaction terms between environmental tobacco smoke exposure at follow-up and SERPINA1 genotype (PiMZ, PiMM as reference), and smoking status through follow-up and SERPINA1 genotype; we estimated the effect of ▵PM10 and high-level VGDF exposure during follow-up in PiMZ and PiMM carriers by adding interaction terms in the model.

  • †Negative signs indicate acceleration of decline in the lung function parameter with higher levels of exposure to the inhalants.

  • ‡p<0.0001 and p=0.03 for interactions between SERPINA1 genotype and high-level VGDF exposure on ▵FEF25–75% and ▵FEV1/FVC, respectively.

  • FVC, forced vital capacity; FEF, forced expiratory flow; FEV, forced expiratory volume; VGDF, vapours, dusts, gases and fumes.