Table 5.

Replication of previously reported EWAS signals for long-term exposure to ${\mathrm{NO}}_2$ and ${\mathrm{PM}}_{2.5}$, in the SAPALDIA study, single- and multiexposure models.

Air pollutant; Cohort (Reference)	CpG ID	CHR	Location	Gene	Beta	SE	$p$-Value	SAPALDIA (single-exposure model)	SE	$p$-Value	SAPALDIA (multiexposure model)	SE	$p$-Value
								Beta			Beta
${\mathrm{NO}}_2$; LifeLines, de FC Lichtenfels et al. 2018	cg04908668	6	32823941	PSMB9	$-0.012$	0.002	$7.94\times {10}^{-9}$	0.0003	0.0003	0.333	0.0004	0.0004	0.322
	cg14938677	7	127231698	ARF5	0.023	0.004	$1.05\times {10}^{-8}$	0.0004	0.001	0.619	0.0004	0.001	0.663
	cg00344801	22	46685728	TTC38	$-0.028$	0.005	$2.38\times {10}^{-8}$	0.001	0.001	0.209	0.001	0.001	0.282
	cg18379295	14	52326155	GNG2	0.020	0.004	$3.50\times {10}^{-8}$	$-0.001$	0.001	0.204	$-0.001$	0.001	0.367
	cg25769469	5	71643841	PTCD2	0.035	0.006	$3.69\times {10}^{-8}$	0.001	0.002	0.547	0.002	0.002	0.237
	cg02234653	2	224625080	AP1S3	$-0.017$	0.003	$4.70\times {10}^{-8}$	0.0005	0.001	0.553	0.0003	0.001	0.752
	cg08500171a	6	31590674	BAT2	0.024	0.004	$9.81\times {10}^{-8}$	0.002	0.001	0.042	0.003	0.001	0.019
${\mathrm{NO}}_2$; EPIC-ITALY, Plusquin et al. 2017	cg08120023	1	116947203	C1orf203	$-0.003$	0.0005		0.001	0.001	0.586	0.002	0.001	0.179
	cg22856765	8	42693384	THAP1	$-0.008$	0.001	$4.27\times {10}^{-9}$	$-0.00001$	0.0002	0.960	$-0.00001$	0.0002	0.930
	cg18164357	11	77534497	C11orf67	$-0.009$	0.001	$9.61\times {10}^{-9}$	0.0005	0.0003	0.042	0.001	0.0003	0.016
	cg13918628	9	35610380	CD72	$-0.012$	0.002	$1.02\times {10}^{-8}$	$-0.0003$	0.0002	0.184	$-0.0005$	0.0003	0.074
	cg03870188	13	113717830	MCF2L	$-0.004$	0.001	$1.02\times {10}^{-8}$	0.0001	0.0003	0.670	0.0001	0.0003	0.650
	cg20939320	3	132563279	NCRNA00119	$-0.006$	0.001	$3.49\times {10}^{-8}$	0.001	0.001	0.091	0.001	0.001	0.185
	cg13420207	7	81666278	CACNA2D1	$\begin{array}{c}-0.010\hfill \end{array}$	0.002	$5.56\times {10}^{-8}$	$-0.00004$	0.001	0.947	$-0.00003$	0.001	0.973
	cg04914283	1	23181832	EPHB2	$-0.005$	0.001	$5.85\times {10}^{-8}$	0.001	0.001	0.298	0.001	0.001	0.118
	cg21156210	4	100485208	RG9MTD2	0.010	0.002	$6.03\times {10}^{-8}$	$-0.00002$	0.0002	0.941	0.0001	0.0003	0.731
	cg16205861	12	54146572	NA	$-0.004$	0.001	$6.57\times {10}^{-8}$	$-0.0001$	0.0005	0.788	$-0.0001$	0.0005	0.882
	cg12790758	15	37369914	MEIS2	$-0.004$	0.001	$7.06\times {10}^{-8}$	0.0006	0.0005	0.287	$-0.0001$	0.001	0.898
	cg18201392	1	185023741	RNF2	$\begin{array}{c}-0.005\hfill \end{array}$	0.001	$8.02\times {10}^{-8}$	0.0002	0.0001	0.118	0.0002	0.0001	0.133
${\mathrm{NO}}_2$; Korean COPD Cohort, Lee et al. 2019	cg05171937	12	27396765	STK38L	0.010	0.002	$1.10\times {10}^{-8}$	0.003	0.001	0.068	0.002	0.002	0.125
	cg06226567	20	22559676	C20orf56	0.003	0.001	$3.50\times {10}^{-8}$	0.00002	0.0001	0.863	0.0001	0.0002	0.514
	cg26583725	13	110397643	NA	$-0.001$	${2.3}^{-4}$	$4.90\times {10}^{-8}$	0.0001	0.0001	0.183	0.0001	0.0001	0.228
${\mathrm{PM}}_{2.5}$; EPIC-ITALY, Plusquin et al. 2017	cg23890774	19	36618841	NA	0.078	0.014	$1.98\times {10}^{-8}$	0.0001	0.0003	0.704	0.0003	0.0003	0.263
${\mathrm{PM}}_{2.5}$; EPIC-NL never-smokers, Plusquin et al. 2017b	cg12575202	10	133331128	NA	$-0.467$	0.080	$5.40\times {10}^{-9}$	$-0.001$	0.003	0.786	$-0.002$	0.003	0.529
	cg08630381	13	100612277	NA	0.461	0.073	$2.58\times {10}^{-10}$	$-0.001$	0.001	0.415	$-0.001$	0.001	0.394
	cg17629796a	13	30707265	NA	$-0.563$	0.094	$2.11\times {10}^{-8}$	$-0.002$	0.001	0.076	$-0.003$	0.001	0.033
	cg07084345	15	61972967	NA	$-0.512$	0.075	$7.26\times {10}^{-12}$	0.002	0.008	0.816	0.002	0.008	0.769
	cg04319606	2	26785290	C2orf70	0.261	0.068	$1.31\times {10}^{-7}$	0.0002	0.002	0.893	$-0.00002$	0.002	0.989
	cg09568355	2	45228633	NA	0.261	0.049	$1.41\times {10}^{-7}$	0.003	0.002	0.286	0.004	0.003	0.179
	cg03513315	2	30988383	PES1	0.307	0.058	$1.35\times {10}^{-7}$	$-0.0003$	0.001	0.631	$-0.0001$	0.001	0.837
	cg25489413	7	44794343	ZMIZ2	$-0.365$	0.068	$6.48\times {10}^{-8}$	0.001	0.002	0.712	0.0002	0.002	0.933
	cg00005622	8	145180403	NA	$-0.398$	0.064	$5.16\times {10}^{-10}$	$-0.004$	0.001	0.109	$-0.004$	0.003	0.136

Note: Beta coefficients represent increase or decrease in DNA methylation in relation to ${\mathrm{NO}}_2$ or ${\mathrm{PM}}_{2.5}$ exposure. In a preliminary step, DNA methylation $\mathrm{\beta }$-values were regressed on the Illumina control probe-derived first 30 principal components to correct for correlation structures and technical bias, and residuals of these regressions covering 430,477 CpGs were used as the technical bias-corrected methylation level at the CpG sites. Extreme values of the residuals (lying beyond three times the interquartile range below the first quartile and above the third quartile at each CpG site) were replaced with their corresponding detection threshold value (“modified winsorization”). The “winsorized” data were then used as the dependent variables in the present EWAS. The multiexposure model contained all five exposures at same time. All SAPALDIA estimates were derived from linear mixed-effects EWAS models, with random intercept at the level of participant, adjusted for age; sex; educational level; area; neighborhood socioeconomic status; greenness index; smoking status; smoking pack-years; exposure to passive smoke; consumption of fruits, vegetables, and alcohol; nested study; asthma status; noise truncation indicators; survey; and leukocyte composition. Multiexposure model included all five exposures (Aircraft, railway, road traffic Lden and respective truncation indicators, ${\mathrm{NO}}_2$ and ${\mathrm{PM}}_{2.5}$) at the same time. CHR, chromosome; COPD, chronic obstructive pulmonary disease; CpG, Cytosine-phosphate-Guanine; EPIC, European Prospective Investigation into Cancer and Nutrition; EWAS, epigenome-wide association study; N.A., not annotated; NL, Netherlands; ${\mathrm{NO}}_2$, nitrogen dioxide; ${\mathrm{PM}}_{2.5}$, particulate matter with aerodynamic diameter $<2.5\mathrm{\mu }\mathrm{m}$; SAPALDIA, Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults; SE, standard error.

^aValidated in the SAPALDIA study.

^bSAPALDIA estimates derived from never-smoker sample comparable to the EPIC-NL never-smoker estimates.