Table 4. Mediation analysis: the mediated effect of air pollution on cardiovascular-related biomarkers through a change in gene-specific methylation.
| Estimates correspond to a standard deviation increase from the mean | ||||
|---|---|---|---|---|
| Particle number | Black carbon | Sulfate | Ozone (March to August) |
|
| γ1β2 estimate [95% CI] |
γ1β2 estimate [95% CI] |
γ1β2 estimate [95% CI] |
γ1β2 estimate [95% CI] |
|
| F3 methylation and fibrinogen protein |
(–0.267)(–0.032) = 0.009 [–0.013, 0.030] |
(–0.142)(–0.084) = 0.012 [0.000, 0.024] |
(–0.054)(–0.099) = 0.005 [–0.003, 0.014] |
(0.023)( –0.088) = –0.002 [–0.021, 0.017] |
| ICAM-1 methylation and ICAM-1 protein | (–0.053)( –0.077) = 0.004 [–0.004, 0.012] |
(0.022)(–0.069) = –0.001 [–0.007, 0.004] |
(-0.090)(–0.075) = 0.007 [0.000, 0.014] |
(–0.441)(–0.085) = 0.037 [0.003, 0.072] |
| TLR-2 methylation and CRP protein | (–0.002)(0.023) = 0.000 [–0.002, 0.002] |
(0.034)( –0.023) = –0.001 [–0.003, 0.002] |
(–0.015)(–0.010) = 0.000 [–0.001, 0.001] |
(–0.140)(–0.130) = 0.018 [–0.010, 0.047] |
| IFN-γ methylation and CRP protein |
(–0.101)(0.008) = –0.001 [–0.008, 0.006] |
(–0.050)(0.039) = –0.002 [–0.006, 0.002] |
(0.021)(0.017) = 0.000 [–0.001, 0.002] |
(0.163)(0.050) = 0.008 [–0.006, 0.023] |
| IL-6 methylation and IL-6 protein | (0.037)(–0.071) = –0.003 [–0.009, 0.003] |
(0.056)( –0.046) = –0.003 [–0.007, 0.001] |
(0.003)(-0.046) = 0.000 [–0.003, 0.002] |
(–0.128)(-0.024) = 0.003 [–0.008, 0.014] |
Variables included in the models: air pollutantb, temperatureb, relative humidityb, age, body mass index, smoking status, diabetes status, statin use, % neutrophils in blood count, % lymphocytes in blood count, seasonal sine and cosine, season, and methylation batch. Air pollutant, temperature, and relative humidity represent the moving average between lags 0 and 27 days.