TABLE 4

Mediation analysis in all participants, never smokers and non-APOE-ε4 carriers

MediatorExposureAll participants (n=520)Never smokers (n=410)non-APOE-ε4 carriers (n=369)
Proportion mediated %p-value mediationProportion mediated %p-value mediationProportion mediated %p-value mediation
Without exposure × mediator interaction
 FEV1PM104.920.0684.810.06410.590.052
 FEV1PM2.55.820.0665.670.07011.650.080
 FEV1NO26.230.1327.190.29811.240.328
 FVCPM103.330.1604.020.1145.020.262
 FVCPM2.54.160.1685.060.1146.090.278
 FVCNO25.830.2027.690.3246.790.486
 FEV1/FVCPM10−3.610.312−0.740.674−4.480.520
 FEV1/FVCPM2.5−3.350.372−0.460.758−3.770.586
 FEV1/FVCNO2−1.810.536−0.130.898−1.900.760
With exposure × mediator interaction
 FEV1PM105.510.0465.220.06810.090.078
 FEV1PM2.56.470.0646.100.08410.840.144
 FEV1NO27.120.0968.850.25011.020.284
 FVCPM103.490.1844.020.1204.670.290
 FVCPM2.54.210.1964.860.1345.460.322
 FVCNO26.340.2269.480.2506.600.466
 FEV1/FVCPM10−2.380.466−0.020.982−3.150.598
 FEV1/FVCPM2.5−1.830.5880.130.960−2.060.732
 FEV1/FVCNO2−2.140.522−0.190.964−2.910.700

Estimated percentage of the association between air pollution exposure and visuo-construction performance (VCP; figure copying) that was mediated by a decrease in lung function. All models were adjusted for age, height, body mass index, socio-economic status, current and former smoking habits (in the analysis of all participants and in the analysis of non-APOE-ε4 carriers), exposure to second-hand smoke, living in an urban area versus a rural area, APOE-ε4 incidence (in the analysis of all participants and in the analysis of never smokers), physical activity and depression. FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; PMx: particles with a 50% cut-off aerodynamic diameter of x µm; NO2: nitrogen dioxide.